Achieving high strength in indirectly-extruded binary Mg–Ca alloy containing Guinier–Preston zones
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When it comes to maintaining a healthy lifestyle,physical exercise is an essential component.Engaging in regular physical activity not only strengthens the body but also enhances mental wellbeing.Here are some key points to consider when writing an essay on the importance of exercising for health:1.Introduction to Physical Exercise:Begin by defining what physical exercise is and why it is important.Mention that it includes a range of activities that improve fitness and overall health.2.Benefits of Regular Exercise:Cardiovascular Health:Explain how regular exercise strengthens the heart and improves circulation,reducing the risk of heart diseases.Muscular Strength and Endurance:Discuss how exercise helps in building and maintaining muscle strength and endurance,which is crucial for daily activities and injury prevention.Mental Health:Highlight the role of exercise in reducing stress,anxiety,and depression,and how it can improve mood and cognitive function.3.Types of Exercise:Aerobic Exercises:Describe activities like running,swimming,and cycling that increase heart rate and improve stamina.Anaerobic Exercises:Explain the importance of weight training and highintensity interval training for building muscle and strength.Flexibility Training:Discuss the benefits of yoga and stretching for improving flexibility and range of motion.4.Importance of a Balanced Routine:Emphasize the need for a balanced exercise routine that includes a mix of aerobic,anaerobic,and flexibility training to cover all aspects of physical fitness.5.Setting Realistic Goals:Advise on setting achievable goals for exercise,which can motivate individuals to stick to their fitness plans and gradually improve their health.6.Overcoming Barriers:Address common barriers to exercise,such as lack of time, motivation,or physical limitations,and suggest strategies for overcoming these obstacles.7.Incorporating Exercise into Daily Life:Provide tips on how to integrate physical activity into daily routines,such as walking or cycling to work,taking the stairs instead of elevators,or participating in sports or group activities.8.Conclusion:Summarize the importance of regular exercise for overall health and wellbeing.Encourage readers to make physical activity a part of their lifestyle for longterm benefits.Remember to use clear and concise language,provide examples,and possibly include personal experiences or anecdotes to make the essay more engaging and relatable.。
In the realm of machining operations, especially in metalworking, the maximum swivel diameter (also known as the maximum swing over bed or chuck) is a critical parameter that significantly impacts the versatility and performance of a lathe machine. This essay provides an in-depth analysis of this concept from multiple perspectives, emphasizing its role in achieving high-quality and precision standards.The maximum swivel diameter refers to the largest diameter of a workpiece that a lathe can rotate around while being machined. It is essentially the distance from the center of the lathe spindle to the outermost edge of the machine's cross-slide or compound rest. This dimension determines the size of the largest cylindrical part that can be rotated and machined within the lathe’s capacity without interference.**Implications for Production Capacity and Versatility**The magnitude of the maximum swivel diameter directly affects the types and sizes of parts a lathe can handle. A larger diameter allows for the processing of bigger components, which is particularly important in industries such as aerospace and heavy machinery manufacturing where large-scale parts are common. Thus, it becomes a decisive factor when choosing a lathe for specific production requirements, ensuring the capability to meet high-volume and large-scale production needs with precision.**Precision and Accuracy**In the pursuit of high-quality standards, the maximum swivel diameter also plays a pivotal role. Lathes with larger diameters typically have more robust and stable structures to accommodate the increased mass and torque during machining operations. This structural stability contributes to improved dimensional accuracy and reduced vibration, thereby enhancing the overall precision of the machining process.Moreover, a lathe's ability to rotate a workpiece through a full 360-degree arc without obstruction by other machine components ensures uniform cutting and finishing across the entire diameter of the workpiece. This feature is crucialfor meeting stringent tolerances and surface finish requirements, hallmarks of high-quality machining.**Tooling and Machining Capabilities**The maximum swivel diameter also influences the choice and configuration of tooling. Larger diameters often necessitate longer tools or specialized holders to reach the workpiece. This aspect demands careful consideration of tool deflection and rigidity to maintain accuracy over long reaches. Advanced tool holding systems and intelligent tool path planning become essential to harness the full potential of a large swivel diameter while maintaining high-quality output.**Safety and Ergonomics**From a safety perspective, understanding and respecting the maximum swivel diameter helps prevent accidents caused by attempting to machine oversized workpieces. Overloading a lathe beyond its rated capacity can lead to equipment damage, compromised part quality, and potential hazards to operators.Additionally, a well-designed lathe with a suitable maximum swivel diameter promotes better ergonomics in the workplace. It allows for easier loading and unloading of workpieces and reduces operator fatigue, contributing to a safer, more efficient working environment that indirectly enhances product quality by reducing human error.**Conclusion**In summary, the maximum swivel diameter of a lathe is a fundamental characteristic that profoundly impacts a workshop's productivity, efficiency, and ability to produce high-quality, precision-machined components. It not only defines the physical limits of the machine but also influences the choice of materials, tooling, machining strategies, and even safety protocols. As such, selecting a lathe with the appropriate maximum swivel diameter is a strategic decision that reflects the commitment to achieving the highest levels of quality and precision in manufacturing processes.Understanding the multifaceted implications of this parameter underscoresits importance in today's industrial landscape, where technological advancements continue to push the boundaries of what's possible in terms of size, complexity, and precision in metalworking and beyond.。
Developing a healthy habit of exercising is essential for maintaining a robust physique and enhancing overall wellbeing.Here are some key points to consider when crafting an essay on this topic:1.Introduction to the Importance of Exercise:Begin by emphasizing the significance of physical activity in our daily lives.Mention how regular exercise can improve cardiovascular health,boost the immune system,and reduce the risk of chronic diseases.2.Understanding the Benefits of Regular Exercise:Elaborate on the various benefits of exercise,such as increased energy levels,better mood,improved sleep quality,and enhanced cognitive function.3.Setting Realistic Goals:Discuss the importance of setting achievable fitness goals. Explain how starting with small,manageable objectives can lead to a sustainable exercise routine.4.Creating a Routine:Describe the process of establishing a regular workout schedule. Highlight the importance of consistency and how it can lead to the formation of habits.5.Choosing the Right Type of Exercise:Explain the different types of exercises,such as aerobic,strength training,and flexibility exercises,and how individuals can choose the ones that best suit their needs and preferences.6.Incorporating Exercise into Daily Life:Offer suggestions on how to integrate physical activity into everyday routines,such as walking or biking to work,taking the stairs instead of elevators,or engaging in active hobbies.7.Overcoming Barriers:Address common obstacles to regular exercise,such as lack of time,motivation,or access to facilities,and provide strategies for overcoming these challenges.8.The Role of Nutrition:Briefly touch upon the connection between exercise and a balanced diet,explaining how proper nutrition supports fitness goals and enhances the benefits of physical activity.9.Staying Motivated:Discuss techniques for maintaining motivation,such as tracking progress,finding a workout buddy,or joining a fitness community.10.LongTerm Commitment:Conclude by emphasizing the need for a longterm commitment to exercise.Explain how turning exercise into a habit can lead to a lifetimeof health benefits.Remember to use clear and concise language,provide relevant examples,and possibly include personal anecdotes or quotes from experts to strengthen your essay.。
Humility is a virtue that has been extolled throughout history.It is often said that great achievements are made by those who are humble,as this quality allows individuals to remain grounded and focused on their goals without being swayed by ego or pride. Here is an essay that explores the idea that humility can lead to great accomplishments.Title:The Power of Humility in Achieving GreatnessIn the pursuit of success,many individuals believe that confidence and assertiveness are the key traits that drive one to the pinnacle of achievement.However,there is another quality that is equally,if not more,important:humility.It is the quiet strength that underpins the greatest of endeavors,allowing individuals to navigate the complexities of life and work with grace and effectiveness.The Essence of HumilityHumility is the ability to recognize ones own limitations and to acknowledge the contributions of others.It is not about selfdeprecation or a lack of selfworth rather,it is an honest assessment of ones abilities and a willingness to learn from others.This openness to new ideas and perspectives is what fuels innovation and growth,both personally and professionally.Humility in LeadershipIn the realm of leadership,humility is a critical component.Leaders who are humble are more likely to listen to the ideas and concerns of their team members,fostering an environment of collaboration and mutual respect.They are also more open to feedback, which is essential for continuous improvement and adaptation to changing circumstances. Humility and LearningThe humble individual is a perpetual learner.They understand that knowledge is vast and that there is always more to discover.This mindset keeps them curious and eager to explore new concepts,which can lead to breakthroughs and advancements in their field of expertise.Overcoming Obstacles with HumilityWhen faced with challenges,a humble person is more likely to seek help and advice rather than trying to tackle problems singlehandedly.This collaborative approach not only lightens the burden but also brings together diverse solutions that might not havebeen considered otherwise.Humility and RecognitionInterestingly,humility often leads to recognition,not because it is sought,but because it is genuinely appreciated by others.People are drawn to those who are genuine, approachable,and willing to share credit.This can lead to a strong network of support and opportunities that might not have been available to someone with a more selfcentered approach.The Role of Humility in ResilienceResilience is the ability to bounce back from setbacks and failures.Humility plays a significant role in this process,as it allows individuals to accept their mistakes and learn from them without being consumed by guilt or shame.This resilience is crucial for longterm success and growth.ConclusionIn conclusion,humility is a powerful force in the journey towards greatness.It is the foundation upon which great leaders,thinkers,and doers build their legacies.By embracing humility,one can achieve a level of success that is not only impressive but also sustainable and deeply fulfilling.Let us,therefore,strive to cultivate this virtue in our daily lives,recognizing that in doing so,we open ourselves up to a world of possibilities and achievements.。
青年人需要奋斗英文作文Here is an 800-word English essay on the topic of why young people need to strive and work hard:The Importance of Striving for Young People。
As young people, we are often told that we need to work hard and strive to achieve our goals. This message is repeated to us by our parents, teachers, and mentors, andit is a sentiment that is echoed throughout society. Butwhy is it so important for young people to adopt this mindset of striving and pushing ourselves to be our best? 。
Firstly, striving and working hard is essential for personal growth and development. When we challengeourselves and step outside of our comfort zones, we areable to learn and grow in ways that would not be possibleif we simply coasted through life. Facing difficulties and overcoming obstacles builds resilience, problem-solving skills, and a sense of accomplishment that cannot beattained through passivity. By striving, young people are able to develop the qualities and abilities that will serve them well throughout their lives.Additionally, a mindset of striving is crucial for achieving one's goals and dreams. It is all too easy to become complacent and settle for less than our full potential. However, if we want to reach the heights of success and fulfillment that we aspire to, we must be willing to put in the hard work and dedication required. Whether our goals relate to our education, our careers, or our personal lives, striving ensures that we are proactive in pursuing these aims rather than waiting for them to simply fall into our laps. 。
2024北京一六六中高一6月月考英语(时长:90分钟)班级:______姓名:______考查目标知识:必修二Unit3、至必修三Unit4词汇、语法能力:阅读能力、写作能力第一部分:完型填空(共10题;每小题1.5分,满分15分)阅读下面短文,掌握其大意,从每题所给的A、B、C、D四个选项中,选出最佳选项,并在答题卡上将该项涂黑。
Anger Is a Gift“Mom, where are you? I’ve been waiting for 10 minutes.” I shouted into the phone.“Honey, sorry. I left the office a bit late and the 1 caused really bad traffic, but I…”I hung up. Conversations like this happen every week. Being a teen is 2 enough, and my parents often make me feel less important than their work.In second grade, I broke my arm on the slide. When the school nurse called my mom, she was too 3 to answer. When the phone call reached my father, he sighed(叹息) and said, “I’m in the middle of research.” I sat in the nurse’s office for hours, before my parents finally 4 to take me to hospital.I wished my parents could keep me company. To make my parents take me seriously, I screamed. I tried to establish my own authority by ignoring their schedule. My mom did everything possible to solve the problem, but nothing 5 until she met that adviser.One day after I shut my door in her face, my mom didn’t complain or cry. Instead, she knocked and said, “I have something to tell you.” I opened the door. “Today I met a really good adviser. He said that every time your daughter is angry, she is just saying: I 6 you.”It dawned on me that my anger was merely a mask for me to 7 my loneliness and disappointment. But facing one’s 8 need is the first step towards being happier. This concept not only helped things between my parents and me but also enabled me to handle conflicts and emotions. I started to pay attention to other people’s 9 When an angry customer approached me at my volunteering job, he was saying, “I need more service.” When a homeless person shouted to me in a parking lot, he was simply saying, “I need food and help.”I am now able to see through the fog of anger and see the real face and heart of other people.Five minutes after I hung up on her, my mom’s car finally appeared through the fog. She rolled down her window and said, “Let’s go to a hotpot place, shall we?” I 10 , “OK, but promise me you won’t be late again.”l.A.rain B.snow C.fog D.wind2.A.hard B.unusual C.interesting D.exciting3.A.upset B.scared C.nervous D.busy4.A.passed by B.drove away C.showed up D.gave in5.A.appeared B.mattered C.happened D.worked6.A.hate B.need C.believe D.understand7.A.avoid B.relieve C.show D.hide8.A.unsatisfied B.typical C.increasing D.physical9.A.behavior B.anger C.reaction D.satisfaction10.A.whispered B.complained C.smiled D.hesitated第二部分:阅读理解(共两节,30分)第一节(共10题;每小题2,满分20分)阅读下列短文,从每题所给的A、B、C、D四个选项中,选出最佳选项,并在答题卡上将该项涂黑。
Growing up, I was always the skinny kid in the corner, the one who could barely lift a backpack without feeling the strain. But as I entered high school, something inside me clicked I wanted to change. I wanted to be strong, not just physically, but mentally and emotionally as well. This transformation wasnt just about lifting weights or doing pushups it was about a holistic approach to becoming stronger.The journey to becoming stronger started with a realization that strength is not just about muscles. Its about resilience, determination, and the ability to face challenges headon. I began by setting small, achievable goals for myself. Each day, I would challenge myself to do one more pushup, to run a little further, or to hold a plank for a few more seconds. These incremental improvements were my first steps towards building physical strength.But physical strength alone wasnt enough. I knew that to truly become strong, I needed to work on my mental fortitude. I started reading books on selfimprovement and psychology, learning about the power of the mind and how our thoughts can shape our reality. I practiced mindfulness and meditation, which helped me to stay focused and calm under pressure.I learned to embrace failure as a stepping stone to success, rather than something to fear or avoid.Emotionally, I worked on building my selfesteem and confidence. I surrounded myself with positive influences and supportive friends who encouraged me to be the best version of myself. I learned to express my feelings openly and honestly, rather than bottling them up and lettingthem fester. I also sought out new experiences and challenges to push myself out of my comfort zone, which helped me to grow and develop as a person.One of the most significant turning points in my journey was when I joined the schools track and field team. It was a whole new world for me, filled with athletes who were already strong and fast. At first, I felt out of place and struggled to keep up. But instead of giving up, I used it as motivation to work harder. I trained every day after school, pushing myself to the limit and beyond. The coachs words, Strength doesnt come from what you can do, but from overcoming the things you once thought were impossible, became my mantra.As the months went by, I started to see changes in myself. I was lifting heavier weights, running faster, and jumping higher. More importantly, I was becoming more confident and resilient. I was no longer the same person who shied away from challenges. I was learning to face them headon and to never give up, no matter how tough things got.But becoming stronger also meant learning to take care of my body. I started eating healthier, incorporating more fruits, vegetables, and lean proteins into my diet. I made sure to get enough sleep and rest, understanding that recovery is just as important as the training itself. I also learned the importance of staying hydrated and fueling my body with the right nutrients to support my growth and development.In conclusion, becoming stronger is a multifaceted journey that involvesphysical, mental, and emotional growth. Its about setting goals, pushing boundaries, and never giving up. Its about building resilience, confidence, and selfesteem. Its about taking care of your body and mind, and understanding that strength comes from within. For me, this journey has been transformative, and I am proud of the person I have become. I am stronger now, not just in body, but in mind and spirit, and I know that I can face whatever challenges life throws my way.。
Discipline and selfmotivation are the cornerstones of achieving ones dreams.In the pursuit of personal growth and success,these qualities are indispensable.The following essay explores the importance of selfdiscipline and selfmotivation in building new dreams and how they contribute to personal development.The Essence of SelfDisciplineSelfdiscipline is the ability to control ones emotions,desires,and actions in order to achieve longterm goals.It is the power to say no to immediate gratification for the sake of a better future.This trait is crucial in various aspects of life,including academics, career,and personal relationships.For instance,a student who is selfdisciplined is more likely to allocate time effectively for studying,leading to better academic performance.The Role of SelfMotivationSelfmotivation is the internal drive that propels an individual to take action towards achieving their goals.Unlike external motivation,which is dependent on rewards or punishments from others,selfmotivation comes from within.It is the fuel that keeps one going even in the face of adversity.A selfmotivated person is not easily deterred by setbacks and is more likely to persist in the pursuit of their dreams.Combining SelfDiscipline and SelfMotivationWhen selfdiscipline and selfmotivation are combined,they create a powerful force that can help individuals overcome obstacles and achieve their dreams.A disciplined and motivated individual is likely to set clear goals,create a plan,and stick to it,even when faced with distractions or challenges.Strategies for Cultivating SelfDiscipline and SelfMotivation1.Set Clear Goals:Define what you want to achieve and why it is important to you.This clarity will serve as a compass guiding your actions.2.Create a Routine:Establishing a daily routine can help in building discipline. Consistency is key to forming habits that support your goals.3.Stay Focused:Eliminate distractions and stay focused on your tasks.This may involve setting boundaries with technology or creating a conducive environment for work or study.4.Reward Yourself:Positive reinforcement can be a powerful motivator.Reward yourself for achieving milestones along the way to keep your motivation high.5.Learn from Failure:看待失败as学习和成长的机会,而不是放弃的理由。
变得积极向上的英语作文英文回答:Becoming a more positive person is a journey that requires effort, dedication, and a willingness to shift your mindset and behaviors. There are numerous strategies that you can employ to cultivate a more positive outlook on life, and the following are some of the most effective:1. Practice Gratitude: Regularly expressing gratitude for the good things in your life can help you to focus on the positive aspects and appreciate the present moment. Keep a gratitude journal, write thank-you notes, or simply take time each day to reflect on the things you aregrateful for.2. Surround Yourself with Positivity: The people you spend time with have a significant influence on your thoughts and feelings. Surround yourself with supportive, optimistic individuals who uplift you and encourage you tosee the best in yourself and the world around you.3. Challenge Negative Thoughts: When negative thoughts arise, challenge them by asking yourself if there is any evidence to support them. Are you catastrophizing orjumping to conclusions? Replace negative thoughts with more realistic and positive ones.4. Focus on Your Strengths: Identify your strengths and areas where you excel. Focus on developing these strengths and using them to your advantage. When you feel capable and confident, it is easier to maintain a positive outlook.5. Set Realistic Goals: Achieving goals can boost your self-esteem and give you a sense of accomplishment. However, it is important to set realistic goals that are achievable. Avoid setting yourself up for failure by setting the bartoo high.6. Engage in Physical Activity: Exercise releases endorphins that have mood-boosting effects. Regularphysical activity can help to reduce stress, improve sleep,and enhance overall well-being.7. Get Enough Sleep: When you are sleep-deprived, you are more likely to experience negative emotions and have difficulty regulating your thoughts and behaviors. Aim for 7-9 hours of quality sleep each night.8. Seek Professional Help: If you are struggling to overcome negative thoughts and emotions on your own, consider seeking professional help from a therapist or counselor. They can provide support, guidance, and coping mechanisms to help you develop a more positive mindset.中文回答:成为一名积极的人是一段需要付出努力、奉献以及改变思维方式与行为的旅程。
Selfdiscipline is a cornerstone of success in all aspects of life.It is the ability to control ones emotions and actions,to resist the temptations of immediate gratification, and to work towards longterm goals.Here is an essay on the importance of selfdiscipline and how it can lead to success.Title:The Power of SelfDisciplineIntroductionIn a world filled with distractions and instant gratification,selfdiscipline stands out as a key to achieving ones aspirations.It is the inner strength that propels individuals to persist through challenges and maintain focus on their objectives.The Essence of SelfDisciplineSelfdiscipline is more than just a character trait it is a skill that can be cultivated.It involves setting clear goals,prioritizing tasks,and managing time effectively.It is about making conscious decisions to do what is necessary,even when it is difficult or uncomfortable.Benefits of SelfDiscipline1.Enhanced Productivity:With selfdiscipline,individuals can accomplish more in less time,as they are less likely to procrastinate or get sidetracked by distractions.2.Improved DecisionMaking:Selfdiscipline enables better choices by allowing individuals to weigh the longterm consequences of their actions against shortterm desires.3.Increased Resilience:Those with selfdiscipline are better equipped to handle setbacks and maintain a positive attitude,as they understand that success is a journey with ups and downs.4.Greater Achievement:Selfdisciplined individuals are more likely to achieve their goals because they are persistent and committed to their objectives.5.Better Health:Selfdiscipline also extends to maintaining a healthy lifestyle,including regular exercise and a balanced diet.Cultivating SelfDiscipline1.Set Clear Goals:Define what you want to achieve and why it is important to you.This clarity provides motivation to stay disciplined.2.Break Down Goals:Large goals can be overwhelming.Breaking them down into smaller,manageable tasks makes them more achievable.3.Establish Routines:Consistent routines help to automate behaviors,reducing the need for willpower and making selfdiscipline easier to maintain.4.Practice Mindfulness:Being present and aware of your actions and thoughts can help you recognize when you are tempted to stray from your path.5.Seek Support:Surround yourself with people who encourage and support your disciplined habits.They can provide accountability and inspiration.Overcoming Obstacles1.Acknowledge Temptations:Recognize that temptations are a normal part of life and that it is the response to these temptations that matters.2.Develop Coping Strategies:Have a plan for when you face challenges or temptations that could derail your discipline.3.Learn from Failures:View setbacks as opportunities to learn and grow,rather than as reasons to give up.4.Stay Flexible:Understand that sometimes plans need to be adjusted.Flexibility can help maintain discipline without becoming rigid or overwhelmed.ConclusionSelfdiscipline is the silent guardian of success.It is the force that allows individuals to rise above their circumstances and achieve greatness.By understanding its importance and actively cultivating selfdiscipline,anyone can unlock their full potential and win in the game of life.In essence,selfdiscipline is not just about what you do,but how you do it.It is about the quality of your actions and the consistency with which you apply them.With selfdiscipline,the world is your oyster,and success is within reach.。
Strength is a fundamental aspect of life that can be cultivated and harnessed to achieve new accomplishments.It is not just about physical power but also encompasses mental and emotional resilience.Here is an essay that delves into the power of strength and how it can forge new achievements.The Power of Strength in Achieving New AccomplishmentsIn the vast tapestry of human endeavors,strength stands as a pivotal thread that weaves through the fabric of success.It is the force that propels individuals to surmount challenges,to break barriers,and to reach new heights of achievement.Strength is not a static attribute but a dynamic force that can be developed and refined over time.Physical Strength:The FoundationAt its most basic level,physical strength is the bedrock upon which many accomplishments are built.Athletes train rigorously to enhance their physical prowess, pushing their bodies to the limits to achieve records and victories.The disciplined pursuit of physical strength not only improves performance but also instills a sense of discipline and determination that can be applied to other areas of life.Mental Strength:The CatalystBeyond the physical,mental strength is the driving force behind innovation and intellectual growth.It is the ability to focus,to persevere through complex problems,and to maintain a clear vision in the face of adversity.Mental strength allows individuals to navigate the complexities of life with a level head and a strategic mindset,leading to breakthroughs in science,technology,and the arts.Emotional Strength:The BalmEmotional strength is the oftenoverlooked component that provides resilience in the face of personal and professional setbacks.It is the capacity to manage emotions,to maintain composure under pressure,and to bounce back from disappointments.Emotional strength fosters empathy,builds relationships,and creates a supportive environment that is conducive to achieving new goals.Cultivating StrengthStrength is not a gift bestowed upon a select few it is a skill that can be cultivated by anyone willing to put in the effort.Regular exercise,mental exercises such as puzzles andstrategic games,and practices like mindfulness and meditation can all contribute to building physical,mental,and emotional strength.Harnessing Strength for New AchievementsWhen strength is harnessed effectively,it becomes a tool for achieving new accomplishments.Whether it is an athlete striving for a world record,a scientist working on a groundbreaking discovery,or an entrepreneur launching a new venture,strength is the common denominator that propels them forward.ConclusionIn conclusion,strength is a multifaceted force that is essential for personal and professional growth.It is the foundation upon which new achievements are built,the catalyst that drives progress,and the balm that heals and fortifies the spirit.By understanding and developing ones strength,individuals can unlock their full potential and reach new pinnacles of success.。
Pursuing dreams is a journey that everyone embarks on at some point in their lives. It is a path filled with challenges,obstacles,and moments of doubt,but also with opportunities for growth,learning,and ultimately,fulfillment.Here is an essay on the importance of having the courage to chase ones dreams.Title:The Courage to Chase DreamsFrom a young age,we are often encouraged to dream big and to aspire to achieve great things.However,the path to realizing these dreams is not always clear,and it requires a certain level of courage to navigate the uncertainties and risks involved.The journey of pursuing ones dreams is a testament to ones resilience,determination,and belief in oneself.The Importance of DreamsDreams serve as the driving force behind our ambitions.They are the aspirations that keep us motivated and focused on our goals.Without dreams,life can become monotonous and devoid of purpose.They inspire us to push beyond our comfort zones and to strive for a future that is better than our present.Overcoming FearThe fear of failure is a common barrier that prevents many from chasing their dreams.It is essential to recognize that failure is not the end but rather a stepping stone towards success.Each failure provides valuable lessons that can be used to improve and refine our approach.Embracing failure as a part of the process can help to alleviate the fear and encourage us to take the necessary risks.Setting Realistic GoalsWhile it is important to dream big,it is equally important to set achievable goals. Breaking down our dreams into smaller,more manageable objectives can make the journey seem less daunting and more achievable.This approach allows for a sense of accomplishment along the way,which can be incredibly motivating.The Role of PersistencePersistence is the key to overcoming the inevitable setbacks and obstacles that will arise on the path to achieving our dreams.It is the unwavering commitment to continue striving for our goals,even when the odds seem stacked against us.Persistence is whatseparates those who achieve their dreams from those who do not.The Power of SupportSurrounding ourselves with supportive individuals can significantly impact our ability to pursue our dreams.Friends,family,and mentors can provide encouragement,advice,and a listening ear during difficult times.Their belief in us can bolster our own selfbelief and give us the strength to keep going.Embracing ChangeChasing dreams often requires change,whether it be in our personal lives,careers,or habits.Being open to change and adaptable in the face of new challenges is crucial.It is through change that we grow and evolve,becoming better equipped to handle the complexities of pursuing our dreams.ConclusionIn conclusion,the courage to chase dreams is a fundamental aspect of personal growth and fulfillment.It involves facing our fears,setting realistic goals,persisting through challenges,seeking support,and embracing change.By taking these steps,we can transform our dreams into reality and experience the profound sense of achievement that comes with realizing our aspirations.Remember,the journey may be long and arduous,but the rewards of reaching our dreams are immeasurable.So,let us all find the courage within us to chase our dreams,for it is in this pursuit that we truly discover our potential and make our mark on the world.。
Strength is a quality that is often admired and sought after in individuals.It is the foundation upon which great achievements are built,and it is what allows people to overcome adversity and achieve their goals.In this essay,we will explore the importance of strength in various aspects of life and how it can lead to the creation of glory.Firstly,physical strength is essential for athletes and individuals who engage in sports or physical activities.It enables them to perform at their best and achieve remarkable feats. For example,Olympic athletes train rigorously to build their strength and endurance, which allows them to compete at the highest level and bring glory to their countries.Secondly,mental strength is crucial for individuals who face challenges and obstacles in their personal and professional lives.It helps them to stay focused,persevere,and maintain a positive attitude despite setbacks.People with strong mental fortitude are more likely to bounce back from failures and continue pursuing their dreams,ultimately achieving success and recognition.Thirdly,emotional strength is vital for maintaining healthy relationships and navigating through lifes ups and downs.It allows individuals to express their feelings openly, empathize with others,and provide support when needed.Emotionally strong people are better equipped to handle conflicts,communicate effectively,and build strong bonds with those around them.Moreover,moral strength is the foundation of integrity and ethical behavior.It guides individuals to make the right decisions,even when faced with temptations or pressures. People with strong moral convictions are respected and admired for their honesty, fairness,and commitment to doing what is right.In conclusion,strength in various forms physical,mental,emotional,and moral plays a significant role in shaping an individuals life and achieving glory.By cultivating these qualities,one can overcome challenges,excel in their chosen field,and earn the respect and admiration of others.Embracing strength as a core value can lead to a fulfilling and successful life,filled with accomplishments and recognition.。
Humility is a virtue that has been celebrated and revered across cultures and throughout history.It is the quality of being modest and respectful,not overly proud or boastful.In the realm of personal growth and achievement,humility plays a crucial role that can often be overlooked.Here is an essay that explores how humility can lead to greatness.Title:The Power of Humility in Achieving GreatnessIn a world that often glorifies selfpromotion and selfaggrandizement,the concept of humility may seem counterintuitive to success.However,it is precisely this undervalued trait that can be the key to unlocking ones full potential and achieving true greatness.The Foundation of HumilityHumility begins with selfawareness.It is the recognition that we are all part of a larger whole and that our individual contributions,while important,are not the sole determinants of our worth.This awareness fosters a sense of gratitude and respect for others,which in turn can lead to more meaningful relationships and a deeper understanding of the world around us.Humility and LearningOne of the most significant benefits of humility is its ability to enhance our capacity for learning.When we approach knowledge with an open mind,acknowledging that we do not know everything,we become more receptive to new ideas and perspectives.This openness can lead to innovation and creativity,as we are not confined by the limitations of our own preconceived notions.Humility and LeadershipGreat leaders are often characterized by their humility.They understand that they do not have all the answers and are willing to listen to the insights and expertise of their team members.This willingness to learn from others fosters an environment of collaboration and trust,which is essential for achieving collective goals.Humility and ResilienceHumility also plays a vital role in building resilience.When we are humble,we are more likely to accept our failures and setbacks as opportunities for growth rather than as personal defeats.This mindset allows us to learn from our mistakes and to persevere inthe face of adversity.Humility and RecognitionAchieving greatness often comes with recognition and acclaim.However,maintaining humility in the face of success is crucial to avoid the pitfalls of arrogance and complacency.By staying grounded and remembering the journey that led to our achievements,we can continue to strive for improvement and maintain a connection with those who supported us along the way.ConclusionIn conclusion,humility is not a barrier to greatness but rather a catalyst.It is the quiet strength that underpins true success.By cultivating humility,we open ourselves up to learning,collaboration,resilience,and the ability to maintain perspective in the face of both challenges and triumphs.Embracing humility is not about diminishing our achievements but about recognizing that our success is part of a larger narrative,one that includes the contributions of many and the potential for continuous growth.。
In the journey of life,persistence is a virtue that is often celebrated and revered.It is the unwavering determination to continue in the face of adversity that propels individuals towards their goals.In this essay,we will delve into the significance of persistence in achieving success,overcoming challenges,and personal growth.The Role of Persistence in SuccessSuccess is not a destination but a journey that requires continuous effort and resilience. Persistence is the fuel that keeps the engine of ambition running,even when the path is fraught with obstacles.It is the quality that allows individuals to push through the barriers that stand between them and their aspirations.For instance,Thomas Edison,one of the most prolific inventors in history,is known for his relentless pursuit of innovation. Despite numerous failures,he persisted,leading to the invention of the light bulb,which revolutionized the world.Overcoming ChallengesLife is a series of challenges,and persistence is the key that unlocks the door to overcoming them.Whether it is academic struggles,career setbacks,or personal hardships,the ability to persevere through tough times is crucial.It is not the absence of challenges but the presence of persistence that defines a persons character.For example, J.K.Rowling,the author of the Harry Potter series,faced multiple rejections before her work was published.Her persistence paid off,and she is now one of the most successful authors globally.Personal Growth and DevelopmentPersistence is not just about achieving external goals it is also about personal growth.It is the inner strength that allows individuals to learn from their mistakes,adapt to new situations,and grow as a person.This growth is essential for developing a strong sense of self,which is the foundation of a fulfilling life.For instance,athletes who train rigorously and consistently,despite the physical and mental strain,often experience not only physical improvement but also a heightened sense of discipline and selfrespect.The Power of Persistence in AdversityIn times of adversity,persistence can be the difference between giving up and pushing forward.It is the force that enables individuals to maintain hope and optimism even when the odds are stacked against them.This resilience is particularly important in todays fastpaced and competitive world,where setbacks are common and the pressure tosucceed is immense.By persisting,individuals can turn failures into stepping stones towards success.ConclusionIn conclusion,persistence is a fundamental trait that can transform dreams into reality.It is the driving force that enables individuals to navigate through lifes challenges and emerge stronger.Whether it is in the pursuit of academic excellence,professional achievements,or personal development,persistence is the key to unlocking ones full potential.It is the silent partner in the journey of life,often unnoticed but always essential. Embracing persistence is embracing the possibility of achieving greatness.。
我想变得更优秀英语作文Certainly, here's a sample English essay to help you improve your English writing skills:Title: Striving for Excellence。
In today's fast-paced world, the pursuit of excellence has become increasingly important. Whether it's in academics, career, or personal development, striving for excellence is a hallmark of success. In this essay, we will explore what it means to be excellent, why it is essential, and how individuals can cultivate excellence in their lives.Excellence is not merely about being the best or outperforming others; it is about surpassing one's previous achievements and constantly pushing the boundaries of whatis possible. It is a mindset, a commitment to continuous improvement and self-refinement. Achieving excellence requires dedication, discipline, and perseverance. It involves setting high standards for oneself andconsistently striving to meet and exceed them.One of the primary reasons why excellence is crucial is its correlation with success. Whether in academics, business, sports, or any other field, those whoconsistently deliver excellence are more likely to achieve their goals and stand out from the crowd. Employers seek out individuals who demonstrate a commitment to excellence because they are seen as reliable, innovative, and capable of producing exceptional results.Moreover, striving for excellence fosters personal growth and fulfillment. When we challenge ourselves to do better, we expand our capabilities, learn new skills, and gain confidence in our abilities. Each milestone of excellence reached becomes a source of pride and motivation to aim even higher. As the saying goes, "Excellence is not a destination; it is a continuous journey."So, how can individuals cultivate excellence in their lives? Firstly, it requires setting clear and achievable goals. By defining what success looks like and breaking itdown into manageable steps, individuals can chart a path towards excellence. Secondly, it involves embracing a growth mindset, which recognizes that abilities can be developed through dedication and hard work. Instead of fearing failure, individuals should view it as an opportunity to learn and improve. Thirdly, seeking feedback and guidance from mentors or peers can provide valuable insights and help identify areas for improvement. Finally, maintaining a healthy balance between work and personallife is essential to sustain long-term excellence. Taking care of one's physical and mental well-being ensures the energy and focus needed to pursue excellence consistently.In conclusion, striving for excellence is a noble endeavor that requires dedication, discipline, and a growth mindset. It is not about being perfect but about constantly pushing oneself to be better than before. By embracing excellence in all aspects of life, individuals can unlock their full potential, achieve their goals, and lead a fulfilling life. As Aristotle famously said, "We are what we repeatedly do. Excellence, then, is not an act but a habit."。
Diligence and perseverance are two virtues that are often celebrated as the cornerstones of success.They are the driving forces that propel individuals to overcome obstacles and achieve their goals,regardless of the challenges they face.Diligence:The Path to MasteryDiligence is the quality of being hardworking and persistent in ones efforts to achieve a goal.It is the habit of putting in consistent and focused effort,day after day,without giving up.Diligent individuals are characterized by their attention to detail,thoroughness, and the ability to stay focused on the task at hand.They understand that success does not come overnight but is the result of consistent effort and dedication.In the pursuit of success,diligence is essential because it allows individuals to develop expertise in their chosen field.Whether it is mastering a new language,excelling in sports, or achieving academic excellence,diligence is the key to acquiring the necessary skills and knowledge.It is through consistent practice and learning that one can improve and refine their abilities.Perseverance:Overcoming AdversityPerseverance is the ability to continue in a course of action even in the face of difficulty or with no assurance of success.It is the mental strength to keep going when the odds are against you.Persevering individuals are not easily discouraged by setbacks instead,they view them as opportunities to learn and grow.In the journey towards success,perseverance is crucial because it enables individuals to bounce back from failures and keep moving forward.It is the quality that helps one to maintain their motivation and commitment to their goals,even when faced with adversity. Perseverance is the force that keeps the fire of ambition burning,even in the darkest times.The Intersection of Diligence and PerseveranceThe combination of diligence and perseverance creates a powerful synergy that can lead to remarkable achievements.Diligence provides the groundwork for consistent progress, while perseverance ensures that this progress is not abandoned in the face of challenges. Together,they form a formidable pair that can break through barriers and surmount obstacles.For example,consider the story of Thomas Edison,who is often credited with saying,Genius is one percent inspiration and ninetynine percent perspiration.Edisons invention of the light bulb was not an overnight success it was the result of thousands of experiments and a relentless pursuit of improvement.His diligence in conducting numerous trials and his perseverance in the face of repeated failures ultimately led to a breakthrough that changed the world.Cultivating Diligence and PerseveranceTo cultivate these virtues,one must start by setting clear and achievable goals.It is important to break down larger objectives into smaller,manageable tasks that can be tackled with daily effort.This approach helps to maintain momentum and provides a sense of accomplishment that fuels further progress.Additionally,developing a growth mindset is essential.This involves embracing challenges as opportunities for learning and understanding that skills and abilities can be developed through hard work and dedication.A growth mindset fosters resilience and the willingness to learn from mistakes,which are inevitable on the path to success.ConclusionIn conclusion,diligence and perseverance are indispensable qualities for anyone seeking success.They are the twin engines that power the journey from ambition to achievement. By cultivating these virtues,individuals can transform their dreams into reality,navigate through the complexities of life,and ultimately reach the summit of their aspirations. Success may not be guaranteed,but without diligence and perseverance,it is certainly unattainable.。
Striving for success is a universal theme that resonates with people across different cultures and backgrounds.The English essay on creating brilliance through perseverance can be approached from various angles,such as personal growth,professional achievements,or societal contributions.Heres a detailed essay on the topic:Title:The Pursuit of Excellence through PerseveranceIn the vast canvas of life,it is the strokes of determination and hard work that paint the masterpiece of success.The journey towards creating brilliance is not an easy one it is fraught with challenges,setbacks,and moments of doubt.Yet,it is through the unwavering spirit of perseverance that individuals rise above these obstacles and achieve greatness.The essence of striving lies in the commitment to ones goals.It is the early morning hours spent poring over books,the late nights dedicated to honing ones craft,and the countless hours of practice that lay the foundation for excellence.This dedication is not just about the pursuit of personal glory but also about the desire to contribute positively to society.One of the key aspects of striving for brilliance is the ability to learn from failure.Every setback is an opportunity to grow,to understand ones weaknesses,and to strengthen them. It is through these trials that individuals develop resilience,a quality that is indispensable for achieving longterm success.Moreover,the process of striving for excellence fosters a sense of humility.It teaches us that no matter how high we climb,there is always more to learn,more to achieve.This humility keeps us grounded and focused on our journey,preventing us from becoming complacent or arrogant.In the professional realm,striving for brilliance often translates into innovation and excellence.It is the relentless pursuit of better solutions,the continuous improvement of products and services,and the unwavering commitment to quality that sets apart successful businesses from the rest.This pursuit not only drives economic growth but also enhances the overall quality of life.On a societal level,the collective striving of individuals can lead to monumental achievements.From the moon landing to the development of lifesaving vaccines,history is replete with examples of what can be accomplished when people come together with a shared vision and a relentless drive to succeed.However,the journey towards creating brilliance is not without its sacrifices.It often requires individuals to forgo immediate pleasures and comforts in pursuit of longterm goals.It demands discipline,focus,and an unwavering belief in ones abilities.In conclusion,the pursuit of excellence through perseverance is a journey that is as rewarding as it is challenging.It is a testament to the human spirits ability to overcome adversity and achieve greatness.By embracing the process of striving,we not only create a legacy of brilliance for ourselves but also contribute to the betterment of society as a whole.。
我们也可以当赢家英语作文Title: Becoming Winners: A Journey of Personal Growth。
In the pursuit of success, the notion of winning often dominates our thoughts and actions. But what does it truly mean to be a winner? Is it solely about achieving victory over others, or does it encompass a deeper, more personal journey of growth and self-discovery?To embark on this exploration, let us first redefine what it means to be a winner. Winning is not merely about outperforming others or attaining external recognition; it is about surpassing our own limitations, pushing past obstacles, and striving for continuous improvement. In essence, winning is a mindset—a relentless commitment to self-improvement and the pursuit of excellence.One fundamental aspect of becoming a winner is cultivating a growth mindset. Rather than viewing challenges as insurmountable obstacles, winners perceivethem as opportunities for learning and growth. They embrace setbacks as valuable lessons, allowing them to develop resilience and perseverance in the face of adversity. By adopting a growth mindset, individuals can unlock theirfull potential and achieve success beyond their wildest dreams.Furthermore, winners understand the importance of setting clear goals and taking proactive steps towardstheir realization. They possess a vision for the future and are unwavering in their determination to turn their dreams into reality. Through careful planning, diligent effort, and unwavering dedication, winners consistently progress towards their objectives, overcoming obstacles with unwavering resolve.Moreover, being a winner entails cultivating essential traits such as discipline, determination, and grit. Success rarely comes easy, and winners understand that it requires relentless discipline and a willingness to make sacrifices along the way. Whether it's waking up early to pursue their passions or putting in extra hours of practice, winners arewilling to do whatever it takes to achieve their goals.Additionally, winners recognize the power of collaboration and teamwork. While individual excellence is important, true success often stems from the collective efforts of a cohesive team. Winners understand the value of leveraging the strengths of others, fostering a supportive environment where everyone can thrive and excel. By working together towards a common goal, individuals can achieve feats that would be impossible to accomplish alone.Furthermore, being a winner extends beyond personal achievement; it encompasses making a positive impact on the world around us. Winners are not only driven by self-interest but also by a desire to contribute to the greater good. Whether it's through acts of kindness, philanthropy, or advocacy for social change, winners strive to leave a lasting legacy that uplifts and inspires others.In conclusion, becoming a winner is not solely about achieving victory in a competitive sense; it is a holistic journey of personal growth, self-discovery, and positiveimpact. By cultivating a growth mindset, setting clear goals, embracing discipline and determination, fostering teamwork, and making a difference in the world, individuals can transcend mere success and become true champions in life. So let us embark on this journey together, striving not only to win but to become the best versions of ourselves.。
Selfdiscipline is a vital trait that can significantly influence an individuals success in various aspects of life.It is the ability to control ones emotions,desires,and actions in order to achieve longterm goals and maintain a sense of order and consistency in ones life. Here is a detailed English essay on the importance of selfdiscipline and how it can lead to great achievements.Title:The Power of SelfDiscipline in Achieving GreatnessIntroductionIn the pursuit of success,many factors come into play,but few are as crucial as selfdiscipline.It is the cornerstone of personal development and the driving force behind the accomplishments of great individuals throughout history.This essay will explore the concept of selfdiscipline,its impact on personal growth,and how it can be harnessed to achieve significant life goals.The Essence of SelfDisciplineSelfdiscipline is more than just a buzzword it is a commitment to a set of principles that guide ones actions and decisions.It involves setting clear objectives,creating a plan to achieve them,and sticking to that plan even in the face of distractions or temptations.It is about delaying gratification,prioritizing tasks,and maintaining focus on what is truly important.SelfDiscipline and Personal GrowthPersonal growth is a continuous process that requires a strong sense of selfawareness and the ability to adapt and improve.Selfdiscipline plays a pivotal role in this journey by:1.Enhancing Time Management:With selfdiscipline,individuals can allocate their time more effectively,ensuring that they are dedicating sufficient time to their goals and responsibilities.2.Building Strong Habits:Good habits are the foundation of success.Selfdiscipline helps in forming and maintaining habits that contribute positively to ones wellbeing and productivity.3.Overcoming Procrastination:Procrastination is a common enemy of productivity. Selfdiscipline equips individuals with the mental fortitude to resist the urge to delay tasks and to tackle them promptly.SelfDiscipline and Goal AchievementThe path to achieving great things is often paved with challenges and obstacles. Selfdiscipline is the key that unlocks the door to overcoming these hurdles:1.Setting and Adhering to Goals:Selfdiscipline enables individuals to set realistic and ambitious goals and to follow through with the necessary actions to achieve them.2.Handling Stress and Pressure:In highpressure situations,selfdiscipline helps to maintain composure and make rational decisions,which are essential for success.3.Staying Motivated:The journey to success can be long and arduous.Selfdiscipline provides the motivation to keep going,even when the going gets tough.Cultivating SelfDisciplineDeveloping selfdiscipline is not an overnight process it requires consistent effort and practice.Here are some strategies to cultivate selfdiscipline:1.Start Small:Begin with small,manageable tasks that can be easily incorporated into daily routines.Gradually increase the level of difficulty as confidence grows.2.Establish Routines:Consistent routines provide a framework that supports selfdiscipline by reducing the need for decisionmaking and increasing predictability.3.Practice Mindfulness:Being present and aware of ones thoughts and actions can help in making conscious choices that align with ones goals.4.Seek Accountability:Sharing goals with others can create a sense of responsibility and provide external motivation to stay disciplined.ConclusionIn conclusion,selfdiscipline is the bedrock of success in all human endeavors.It is the force that propels individuals to overcome challenges,to persist in the face of adversity, and to achieve their dreams.By understanding and applying the principles of selfdiscipline,anyone can unlock their potential and make significant strides towards greatness.。
LetterAchieving high strength in indirectly-extruded binary Mg–Ca alloy containing Guinier–PrestonzonesHucheng Pan,Gaowu Qin ⇑,Yuping Ren,Liqing Wang,Shineng Sun,Xiangying MengKey Laboratory for Anisotropy and Texture of Materials (Ministry of Education),Northeastern University,Shenyang 110819,Chinaa r t i c l e i n f o Article history:Received 28October 2014Received in revised form 10January 2015Accepted 13January 2015Available online 19January 2015Keywords:Magnesium alloys Mg–CaIndirect extrusion G.P.zoneMechanical propertiesa b s t r a c tWe developed a high strength Mg–1wt.%Ca binary alloy by an integrated method comprising of conven-tional casting,homogenization and indirect extrusion.The as-extruded Mg–Ca alloy exhibits superior mechanical properties compared with the currently reported results,possessing a tensile yield strength of 310MPa and an ultimate tensile strength of 330MPa,which is attributed to the combined effects of fine dynamically recrystallized grains and nanoscale Mg 2Ca heterogeneous phases.It is worthy to empha-size that a high density of Guinier–Preston (G.P.)zones appear and are expected to play important roles in precipitation hardening and pinning the grain growth of a -Mg matrix.Ó2015Elsevier B.V.All rights reserved.1.IntroductionMagnesium alloys have received increasing interests as struc-tural materials due to unique advantages such as low density and specific strength,and thus they have been widely utilized in vehicles to achieve a lightweight design [1–3].Besides that,Mg alloys,with proper mechanical and biocompatible properties,have great potentials as load-bearing degradable biomaterials,for exam-ple,artificial human bones [4,5].Among various candidates,it has been confirmed that the corrosion resistance of binary Mg–Ca alloys (Ca <2wt.%)is the mostly comparable with pure Mg metal because of the anodic role of Mg 2Ca phase in the Mg–Ca binary alloys [6],which thus results in a lower degradation rate than the other Mg-based biomaterials [7].Moreover,the released Ca component is beneficial for the bone regeneration.With these advantages,Mg–Ca binary alloys are expected to be one of the most promising candidates for high-performance biomaterials [7].Recent studies have been focused on improving mechanical properties of Mg–Ca binary alloys [6–8].For example,Seong et al.[6]improved the strength of binary Mg–Ca alloy through a microstructure refinement via a high-ratio differential speed roll-ing method.Recently,by combining with an indirect extrusion process,the extruded Mg–1wt.%Ca alloy was achieved,reaching a moderate yield strength (YS)of 185MPa and an ultimate strength (UTS)of 239MPa [7].However,a further improvement on the strength of binary Mg–Ca alloys is still expected to maintain a long-term structural stability during biodegradation.In fact,the considerable efforts have been devoted to resolve these issues by alloying and/or deformation in this field [9,10].Precipitation hard-ening has been proven as an effective route in newly developed wrought Mg alloys,such as the low-cost Mg–Zn-,Mg–Sn-and Mg–Ca-based systems [11–15].For example,the twin roll cast Mg–6.2Zn–0.5Zr–0.2Ca alloy shows both high YS (>300MPa)and excellent formability due to uniform precipitation of Mg(Zn,Zr)particles [12].With presence of high melting point Mg 2Sn phases,the both Mg–8Sn–1Zn–1Al wt.%and Mg–10Sn–3Zn–1Al wt.%alloy could be extruded at a wide ram speed of 0.1–6.7mm/s,and YS of the samples range from 199MPa to 319MPa,with the elongation of 6–15%[13,14].Moreover,grain refinement hardening has also been employed widely.For example,the novel method of aging prior to extrusion was applied on Mg–7.6Al–0.4Zn wt.%alloy,thus grain size was reduced to be $8.4l m and YS of the sample could reach 210MPa [16].The Mg–3Al–1Zn wt.%alloy with YS of 220MPa was successfully extruded at low temperature of 250°C by indirect extrusion method,and the grain size of 1.8l m was obtained [17].Recently,high-pressure torsion was applied on both the binary Mg–3.4at.%Zn and ZK60alloys,ultra-fine grains in size of 0.14–1l m were produced [18,19].All these studies evidently indicate that both the grain refinement and precipitation of hard-ening phases can significantly contribute to the enhancement of mechanical properties of Mg alloys.More interestingly,Yu et al.[20]showed that an increased den-sity of dynamic precipitates can be generated at a relatively low/10.1016/j.jallcom.2015.01.0680925-8388/Ó2015Elsevier B.V.All rights reserved.⇑Corresponding author.E-mail address:qingw@ (G.Qin).extrusion temperature for the Mg–8Al–0.5Zn wt.%alloys,effec-tively suppressing the growth of dynamically recrystallized grains of a-Mg matrix,thus a high YS of403MPa was obtained.It is also well known that a homogenization treatment procedure can increase the density of nano-scale heterogeneous particles,result-ing from the precipitation during the following extrusion[15,21]. In this context,we herein applied an indirect extrusion to the suf-ficiently homogenized binary Mg–1Ca ingot at a relatively low temperature.By integrating with conventional casting,homogeni-zation and indirect extrusion together,we reasonably expect to achieve high-performance mechanical properties of Mg–Ca alloys.2.ExperimentalThe Mg–1Ca alloy ingot was prepared by melting commercial pure Mg,Ca in an electrical resistance furnace,and$0.1wt.%Mn was added to remove the Fe impu-rity in the Mg raw material during melting the Mg–Ca alloy[22],because trace Fe had serious deterioration effects on corrosion resistance.Finally,the melt was poured into the pre-heated steel mold with the protection of mixture gas of CO2 and SF6(100:1).The actual contents of Ca and Mn elements in the ingot were chem-ically analyzed to be1.05wt.%and0.097wt.%.Homogenization treatment was con-ducted at500°C for12h with protection of graphite powders,and then the sample was quenched into cold water.The ingot was indirectly-extruded at300°C and 350°C,respectively(named as1Ca-300and1Ca-350)with an extrusion ratio of 20and a ram speed of2mm/s.The mechanical properties of bars were tested on the Shimadzu AG-X Plus250kN at an initial tensile strain rate of1Â10À3sÀ1. The X-ray diffraction(XRD,Philips PW3040/60X’Pert PRO with Cu K a radiation) was used to identify constituent phases of the as-cast and as-extruded samples. The developed textures of extruded samples were measured via XRD.The micro-structures of specimens were examined by optical microscope(OM,Olympus GX),scanning electron microscope(SEM,JEOL JEM-2100F,accelerating voltage of 20kV,working distance of10mm)equipped with energy dispersive spectrometer (EDS)and transmission electron microscope(TEM,JEOL JSM-7001F).Thin foils for TEM were prepared by mechanical polishing($40l m)and then ion beam thinning (GATAN,working voltage of4.5V and thinning angle of7°between the incident beam and the sample surface,at vacuum and cooled atmosphere by liquid nitro-gen).TEM observation was conducted at an accelerating voltage of200kV.3.Results and discussionFig.1shows SEM images of the as-cast and extruded bars.The as-cast sample(Fig.1a)exhibits dendritic a-Mg microstructures with inter-dendritic eutectic-phases.After the homogenization and extrusion processing(Fig.1b),most of the bulk phases in the as-cast sample were dissolved into matrix,while the other phases are seriously fractured and distributed homogeneously.XRD pat-terns(Fig.1c)and EDS results(not shown)furthermore confirm that the bulk and dotty contrasts correspond to the Mg2Ca phases.size evolve to be$5%,5l m and$1.2l m,respectively.A large number of Mg-and Ca-enriched nano-particles,confirmed by EDS,are also observed both among the matrix and along the grain boundaries,as marked by the arrows in Fig.2c and d.Fig.2c1and c2shows the enlarged morphology of a typical nano-particle and the corresponding Fast Fourier Transformation(FFT)pattern, which confirm that the nano-particle is the Mg2Ca phase and a new orientation relationship with matrix can be determined as [11À20]p||[1À210]a and(0001)p||(10À11)a.It is believed that these nano-Mg2Ca phases could pin the DRXed grain boundaries and suppress the grain growth during extrusion,leading to the severe refinement of DRXed grains(Fig.2c and d)[23].The(0002)X-ray polefigures of the Mg–Ca samples extruded at both300°C and350°C are analyzed to assess the grain orienta-tion evolution,as shown in Fig.2e.The sample extruded at300°C exhibits an unusualfiber texture with h0001i axis of the Mg matrix tilting about30°away from the radial direction,and a max-imum texture intensity of16.9.With increasing extrusion temper-ature to350°C,more random texture with a decreased intensity of 10.3is detected.Previous studies demonstrated that the DRXed grains usually represent a relatively weak texture.For example, the grains nucleated by the particle stimulated nucleation(PSN) mechanism are proven to be random in orientation,which leads to the weak texture[15,24].So the low texture intensity in the sample extruded at350°C might be attributed to the increased volume fraction of the DRXed grains(Fig.2b).Fig.3a and b shows the brightfield TEM images of the Mg–Ca samples extruded at both300°C and350°C with electron beam parallel to[11À20]a,and the corresponding selected area electron diffraction(SAED)patterns are displayed in Fig.3A and B,respec-tively.A considerable number of plate-like precipitates,with $1nm in thickness and$40nm in length,lie on the basal plane of the a-Mg matrix for the sample extruded at300°C(Fig.3a). TEM image in a higher magnification taken from the area A marked by a circle in Fig.3a is shown in Fig.3c.Together with EDS ana-lyzes,the rectangular regions(position1)and the plate-like regions(position2)are verified to be Ca-enriched(Fig.3c1).The rectangular phase with$35nm in length and$18nm in width, was also observed in the over-aged Mg–0.3Ca–0.3Zn(wt.%)alloys, which was identified as Mg2Ca phase in Ref.[25].Moreover,it is usually recognized that Mg2Ca phase is the only precipitation phase in the Mg-rich region of Mg–Ca binary alloys,as confirmed by the electron diffraction in this work.Based on these evidences, the rectangular regions are reasonably thought to be Mg2Ca phases in the Mg–Ca alloys.images of the(a)as-cast sample and(b)sample extruded at300°C observed over cross-section of rods,(c)XRD patterns for the as-cast and theH.Pan et al./Journal of Alloys and Compounds630(2015)272–276273micrographs and(c)and(d)TEM images of the as-extruded samples.(a)and(c)are the sample extruded at300°C,and enlarged morphology of typical nano-particles in(c)and the corresponding FFT patterns are included in c1and c2.Textures Extrusion direction and radial direction are marked as ED and RD,respectively.images of samples extruded at the(a)300°C and(b)350°C with electron beam parallel to[11À20]a.Diffraction patterns magnification TEM image taken from the area marked as A in(a),containing the rectangular nano-phases and G.P.zones.respectively.The corresponding FFT patterns of the area2marked as square are inserted as inset in(c).The radial directionpatterns of G.P.zones observed in Mg–Ca–Zn alloys [25,26]and other Mg–RE alloys [27].Based on these observations,the plate-like phases are considered to be coherent with a -Mg matrix and are thus regarded as G.P.zones.In the sample extruded at 350°C,similar microstructures of numerous G.P.zones can be observed (Fig.3b).However,by comparing two samples,it can be found that size of G.P.zones (about 0.5nm in width and 18nm in length)in the sample extruded at 350°C is much smaller than the one at 300°C and bulk Mg 2Ca phases are rarely detected.In fact,G.P.zones formation requires both mass transfer and presence of the sufficient density of vacancies.A high density of defects,such as vacancies and dislocations,could be generated in Mg alloys processed by plastic deformation [28].Even though excess vacancies would decrease rapidly to the half of its original state within a few hours due to the migrations to the dislocations and grain boundaries,it finally presents a slow decay and approaches an equivalent level [29].It can be expected that the present extrusion processing at high temperature can also provide a large number of defects.Moreover,high concentrations of vacan-cies could have been formed during the high-temperature homog-enization process (500°C)which could be remained in the a -Mg matrix by quenching.The stress field around these defects would become the driving force for mass transfer [30],resulting in the formation of the solute clusters.The high density of vacancies can also approach the solute to form the vacancy–Ca clusters.Moreover,the dislocations pipe and vacancies flux can provide fast diffusion paths for the solute clusters [31],which eventually evolve to be the G.P.zones.However,it is worthy to note that the G.P.zones formation strongly depends on the concentration of disloca-tions/vacancies in metallic alloys [32].At the extrusion tempera-ture of 350°C for the present Mg–Ca system,the internal stress could be released and the dynamic recovery is promoted [33].Thus the concentration of dislocations/vacancies can be decreased sig-nificantly,and the dynamic formation of G.P.zones is restricted,as shown in Fig.3b,revealing a reduced size of the G.P.zones.Nev-ertheless,the above observation shows the dynamical precipita-tion behavior of the extruded Mg–Ca alloy is extremely different from the conventional quench-aging of binary Mg–Ca alloy,where only the basal type Mg 2Ca phases are precipitated [34].As to thethermodynamic reason for the G.P.zones formation in the Mg–Ca binary system,it needs a further study in the near future.Fig.4shows the engineering tensile stress–strain curves of the as-extruded Mg–1Ca samples.The sample extruded at 300°C exhibits a YS of 310MPa,an UTS of 330MPa and an elongation to failure (EL)of $4%.For the sample extruded at 350°C,the YS and the UTS decrease slightly to be 280MPa and 310MPa,respec-tively,while the EL increases up to $9.5%.The YS of sample extruded at 300°C is higher than those of previously reported Mg–Ca binary alloys,such as Mg–1Ca (185MPa),Mg–2Ca (205MPa)and Mg–3Ca (249MPa)[7].Besides,the YS of the pres-ent sample is higher than the commercial AZ31extruded at 270°C (178MPa)[35],and is even higher than those of the newly devel-oped high-strength Mg–6Zn–0.4Ag–0.2Ca–0.6Zr (ZQXK6000)alloy (288MPa)[23],Mg–4.7Zn–0.5Ca (ZX50)alloy (291MPa)[36]and Mg–9.8Sn–1.2Zn–1.0Al alloy (TZA911)(308MPa)[35].The detailed comparisons of yield strengths among these alloys are listed in Table 1.In general,the enhanced YS of extruded sample is evidently related to the grain size of the a -Mg matrix,texture and dynamic precipitation.Grain refinement strengthening mechanism is usu-ally described by the Hall–Petch (HP)equation:r ys ¼r 0þk y d À0:5,where d is the average grain diameter,r 0is the friction stress and k y is the HP slope [37].Previous studies showed that the parameters for HP relationship in Mg alloys depend on the texture and grain size,and the hardening effect is more obvious than that of Al alloys due to the higher k y value [38].It is shown that the mean grain size of the as-extruded samples are approximately 1.4–2.3l m by averaging the unDRXed and DRXed grain regions,and consequently such grains refinement would play important roles in achieving the high YS for the present 1Ca-300and 1Ca-350alloys.Following the texture that h 0001i of Mg matrix tilted about 30°away from the radial direction,both the basal and pris-matic slip can be activated during tensile deformation since the Schmid factor for the basal slip increases [39].Considering the low critical shear stress of the basal slip [40],the YS of the sample could be reduced compared to the case with a strong fiber texture.However,the precipitation strengthening due to the copious G.P.zones and nano-Mg 2Ca phases can compensate the strength loss from texture.Notably,the orientation of G.P.zones with respect to the Mg matrix is critical for the strengthening effect.Nie [41]reported that plate-like precipitates formed on prismatic planes of Mg matrix are most effective in dispersive strengthening by developing the Orowan equation that is appropriate for Mg alloys with rods/plates precipitate.The comparison result also shows that plate phases formed on the basal plane,e.g.the G.P.zones in present samples,could considerably contribute to the strength of Mg alloys by providing barriers for gliding dislocations,if their interspacing is small enough.Accordingly,the G.P.zones uniformly distributed in as-extruded sampled with interspaces of about 45nm would readily enhance the YS substantially [42],where the additional stresses have to be applied on dislocations to overcome the obstacles from the second phases.The much higher tensile strength achieved in this study compared with pre-vious work of the binary Mg–Ca wrought alloys can be attributed to the processing method of a lower extrusion temperature and a more sufficient solution treatment [6–8].On the other hand,the higher ductility of 9.5%in the sample extruded at 350°C is consid-ered resulting from the higher volume fraction of DRXed grainsand4.Engineering tensile stress–strain curves of the Mg–1Ca samples extruded °C and 350°C,respectively.Table 1Comparison of the YS among the present Mg–1Ca samples extruded at 300°C,350°C and the samples reported in literatures.Samples 1Ca-3001Ca-3501Ca [7]2Ca [7]3Ca [7]AZ31[35]ZQXK6000[23]ZX50[36]TZA911[35]YS (MPa)310280185205249178288291308Compounds 630(2015)272–276275the weaker texture intensity,where more dislocations on the basal plane could be induced due to the easier activation of basal h a i slip mechanism,thus more plastic deformation could be accumulated [43,44].In the as-extruded Mg–Ca alloy,thefine grain microstructure stems from the dynamic recrystallization[23,35].The precipita-tions play important roles in refining a-Mg grain size of the extruded binary Mg–Ca alloy.As seen in Figs.2and3,a large num-ber of nano-scale Mg2Ca particles and the G.P.zones disperse along grain boundaries and among matrix.Since both the high density of dislocations and vacancies are introduced during extrusion,the defects can provide the driving force and the nucleation sites for forming the precipitates,which in turn drag the grain boundary movement and suppress the grain growth of a-Mg matrix [35,36],and thus contribute to an enhanced strength in Mg–1wt.%Ca alloy.4.ConclusionsIn summary,Mg–1wt.%Ca alloys were indirectly extruded at 300°C and350°C,respectively,resulting in the formation of ultra-fine DRXed grain size of1.0–1.2l m,and a high density of G.P.zones.The extruded bar exhibited a high YS of310MPa and an UTS of330MPa.The microstructure analyzes evidenced that the high strength was mainly resulted from the refined DRXed grains,as well as the combined effect of the nano-scale heteroge-neous Mg2Ca particles and the G.P.zones.AcknowledgementsThe authors acknowledge thefinancial support from National Natural Science Foundation of China(Nos.51171043and 51371046),National863High-Tech Project(No.2013AA031601) and Changjiang Scholars and Innovative Research Team in Univer-sity(No.IRT0713).References[1]A.A.Luo,J.Magnesium Alloys1(2013)2–22.[2]H.C.Pan,F.S.Pan,J.Peng,J.Gou,A.T.Tang,L.Wu,H.W.Dong,J.Alloys Comp.578(2013)493–500.[3]G.W.Qin,Y.P.Ren,W.Huang,S.Li,W.L.Pei,J.Alloys Comp.507(2010)410–413.[4]M.P.Staiger,A.M.Pietak,J.Huadmai,G.Dias,Biomaterials27(2006)1728–1734.[5]P.R.Cha,H.S.Han,G.F.Yang,Y.C.Kim,K.H.Hong,S.C.Lee,J.Y.Jung,J.P.Ahn,Y.Y.Kim,S.Y.Cho,J.Y.Byun,K.S.Lee,S.J.Yang,H.K.Seok,Sci.Rep.3(2013)1–6.[6]J.W.Seong,W.J.Kim,Acta Biomater.11(2015)531–542.[7]Y.S.Jeong,W.J.Kim,Corros.Sci.82(2014)392–403.[8]S.E.Harandi,M.Hasbullah Idris,H.Jafari,Mater.Des.32(2011)2596–2603.[9]B.Lv,J.Peng,Y.Peng,A.Tang,J.Magnesium Alloys1(2013)94–100.[10]H.D.Zhao,G.W.Qin,Y.P.Ren,W.L.Pei,D.Chen,Y.Guo,J.Alloys Comp.509(2011)627–631.[11]K.Hono,C.L.Mendis,T.T.Sasaki,K.Oh-ishi,Scr.Mater.63(2010)710–715.[12]T.Bhattacharjee,B.C.Suh,T.T.Sasaki,T.Ohkubo,N.J.Kim,K.Hono,Mater.Sci.Eng.,A609(2014)154–160.[13]W.L.Cheng,H.S.Kim,B.S.You,B.H.Koo,S.S.Park,Mater.Lett.65(2011)1525–1527.[14]F.R.Elsayed,T.T.Sasaki,T.Ohkubo,H.Takahashi,S.W.Xu,S.Kamado,K.Hono,Mater.Sci.Eng.,A588(2013)318–328.[15]S.Xu,K.Oh-Ishi,S.Kamado,F.Uchida,T.Homma,K.Hono,Scr.Mater.65(2011)269–272.[16]J.-G.Jung,S.H.Park,H.Yu,Y.M.Kim,Y.-K.Lee,B.S.You,Scr.Mater.93(2014)8–11.[17]B.Kim,C.H.Park,H.S.Kim,B.S.You,S.S.Park,Scr.Mater.76(2014)21–24.[18]F.Meng,J.M.Rosalie,A.Singh,H.Somekawaa,K.Tsuchiya,Scr.Mater.78(2014)57–60.[19]S.A.Torbati-Sarraf,ngdon,J.Alloys Comp.613(2014)357–363.[20]H.Yu,S.H.Park,B.S.You,Mater.Sci.Eng.,A610(2014)445–449.[21]T.Homma,N.Kunito,S.Kamado,Scr.Mater.61(2009)644–647.[22]T.Zhu,P.Fu,L.Peng,X.Hu,S.Zhu,W.Ding,J.Magnesium Alloys2(2014)27–35.[23]K.Oh-ishi,C.L.Mendis,T.Homma,S.Kamado,T.Ohkubo,K.Hono,Acta Mater.57(2009)5593–5604.[24]S.W.Xu,K.Oh-ishi,H.Sunohara,S.Kamado,Mater.Sci.Eng.,A558(2012)356–365.[25]J.C.Oh,T.Ohkubo,T.Mukai,K.Hono,Scr.Mater.53(2005)675–679.[26]K.Oh-ishi,R.Watanabe,C.L.Mendis,K.Hono,Mater.Sci.Eng.,A526(2009)177–184.[27]M.Nishijima,K.Hiraga,M.Yamasaki,Y.Kawamura,Mater.Trans.49(2008)227–229.[28]J.Cizek,I.Prochazka,B.Smola,I.Stulikova,Acta Phys.Pol.,A107(2005)738–745.[29]O.Melikhova,J.Cizek,P.Hruska,M.Vlcek,Defect Diffus.Forum322(2012)151–155.[30]D.Blavette,E.Cadel,A.Fraczkiewicz,A.Menand,Science286(1999)2317–2319.[31]J.Huang,M.Meyer,V.Pontikis,Phys.Rev.Lett.63(1989)628–631.[32]T.Hu,K.Ma,T.D.Topping,J.M.Schoenung,vernia,Acta Mater.61(2013)2163–2178.[33]H.Borkar,R.Gauvin,M.Pekguleryuz,J.Alloys Comp.555(2013)219–224.[34]J.F.Nie,Metall.Mater.Trans.A43(2012)3891–3939.[35]S.Park,B.You,Scr.Mater.65(2011)202–205.[36]H.Somkawa,T.Mukai,Mater.Sci.Eng.,A459(2007)366–370.[37]W.Yuan,S.K.Panigrahi,J.Q.Su,R.S.Mishra,Scr.Mater.65(2011)994–997.[38]S.M.Razavi,D.C.Foley,I.Karaman,K.T.Hartwig,O.Duygulu,L.J.Kecskes,S.N.Mathaudhu,V.H.Hammond,Scr.Mater.67(2012)439–442.[39]D.L.Yin,J.T.Wang,J.Q.Liu,X.Zhao,J.Alloys Comp.478(2009)789–795.[40]B.Song,R.Xin,G.Chen,X.Zhang,Q.Liu,Scr.Mater.66(2012)1061–1064.[41]J.F.Nie,Scr.Mater.48(2003)1009–1015.[42]J.D.Robson,N.Stanford,M.R.Barnett,Acta Mater.59(2011)1945–1956.[43]T.Liu,Y.D.Wang,S.D.Wu,R.Lin Peng,C.X.Huang,C.B.Jiang,S.X.Li,Scr.Mater.51(2004)1057–1061.[44]B.L.Wu,Y.H.Zhao,X.H.Du,Y.D.Zhang,F.Wagner,C.Esling,Mater.Sci.Eng.,A527(2010)4334–4340.276H.Pan et al./Journal of Alloys and Compounds630(2015)272–276。