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Thermal Analysis of Self-Propagating High-Temperature Reactions in Titanium, Boron, and Aluminum Pow

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METALLURGICALANDMATERIALSTRANSACTIONSAVOLUME30A,MARCH1999—781ThermalAnalysisofSelf-PropagatingHigh-Temperature

ReactionsinTitanium,Boron,andAluminumPowder

Compacts

L.H.CHIU,D.C.NAGLE,andL.A.BONNEY

Thisarticlefocusesonthecharacterizationofself-propagatinghigh-temperaturesynthesis(SHS)

reactionsthatoccurinpowdercompactscontainingtitanium,boron,andaluminum.Interestinthis

powdersystemisbasedonthecriticalneedtodevelopnewjoiningtechniquesforbondingceramics

tometals.Theexothermicreactionsofparticularinterestinthisstudyincludethosethatgenerate

TiB2,TiB,Ti3Al,andTiAlfromtheirelementalpowders.Datafromdifferentialthermalanalysis

(DTA),thermogravimetricanalysis(TGA),andX-raydiffractometryarepresented.Theseresults

demonstratethatthegasphasesurroundingtheSHSpowdersplaysanimportantroleininitiating

theSHSreactionandindeterminingwhichreactionproductswillforminthefinalbond.

I.INTRODUCTION

FORtheoptimumperformanceofmanyaerospace,

commercial,andmilitarysystems,theuseofdissimilarma-

terialsisbecomingincreasinglynecessary.[1,2]Therefore,

thejoiningofadvancedmaterials,composites,andceramics

tometalstructuresisaprominentissue.[3]Thejoiningof

ceramicstometalspresentsaparticularlydifficulttask,due

tothedifferencesinmechanicalandthermalpropertiesof

thesematerials.Thesedifferencescanleadtoexcessive

stressatthejoininginterfaces,causingmechanicalfailure

intheformofmicrocracks.[4]Currenttechniquesforjoining

theseadvancedmaterialsincludetheuseofpolymer-based

adhesion,mechanicalfastening,andwelding.Ingeneral,

polymericadhesivesdonotenhancetheoverallperform-

anceofthestructure.Also,commerciallyavailablepoly-

mericadhesiveswilldegradeattemperatureshigherthan

180ЊC.[5]Thisseverelylimitstheapplicationsinwhich

polymericadhesivescanbeused.Mechanicalfasteners,

suchasboltsandsleeves,concentratestressesandincrease

thechancesofbrittlefractureand,ultimately,failureofthe

ceramicpart.Toalleviatetheseproblems,ceramicpartsare

oftenmetallized,whichaddsstepsinthemanufacturing

processandincreasesthetotalcostofthecomponent.[6]

Also,partsmustbedesignedtodistributestressesresulting

frommechanicalfasteningashomogeneouslyaspossible.

Welding,ontheotherhand,oftenresultsinoxidization

and/orrecrystallizationofthemetal,especiallywhenare-

pairisperformed.Manyweldingcompoundsdonotwet

ceramiccomponents.Differencesinthethermalexpansion

oftheweldmaterialandsubstratecanalsoleadtobond

failure.[6]Further,speciallytrainedweldersareusually

needed,whichaddstothecostofjoining.

Theultimategoalofthisresearchistoinvestigatethe

joiningofceramicstometalsbyself-propagatinghigh-tem-

L.H.CHIU,formerlywiththeMaterialScienceandEngineeringDepartment,JohnsHopkinsUniversity,iswithParatek,Inc.,Aberdeen,MD21001.D.C.NAGLEiswiththeMaterialScienceandEngineeringDepartment,JohnsHopkinsUniversity,Baltimore,MD21218.L.A.BONNEY,formerlywiththeMaterialsScienceandEngineeringDepartment,JohnsHopkinsUniversity,iswithBicron,Solon,OH44139.ManuscriptsubmittedJanuary13,1998.peraturesynthesis(SHS)reactions.Thermitereactionsin-

volvingmetal-oxidereactionshavebeenusedformany

decadestojoinsteelstructures.[7]Incontrasttothermite

reactions,theSHSreactionsareprimarilyusedtoproduce

refractorymetalcompoundsandceramicsfromcompacted

mixturesofelementalpowders.[8,9]Likethermitereactions,

SHSreactionsaretypicallyinitiatedbyheatingasmallpor-

tionofthepowdercompactwithahotfilamentorflame.

Onceinitiated,theexothermicheatissufficienttopropa-

gatethereactionthroughoutthemixture.Themainadvan-

tageofusingthismethodforjoiningisthegenerationof

hightemperatures(1200ЊCto4000ЊC)[10]forshortperiods

oftime,whichminimizestheheat-affectedzoneinthe

metal.TheveryhighheatoftheSHSreactioncanalso

desorbtheimpuritiesphysicallyadsorbedonthepowder

surfaces.[11]Thismethodoffersthepotentialforthefield

bondingofcomponentsatarelativelylowcost,sincethese

bondjointscanbemadewithalmostnocapitalequipment.

Manyofthesereactionscanbeinitiatedbya12Vbattery

andusuallyrequirenospecialtraining.

TheSHSreactionsinvestigatedinthisstudyaresimilar

toSHSprocessesdescribedbyNagleetal.[12]forformation

ofdiscontinuousmetal-matrixcomposites,whereceramic

reinforcementsareformedinsituinahostmetalmatrix.

Moshieretal.,[13]intheirpatent,revealamethodforbond-

ingmetalsandmetal-matrixcompositestoothermetal-

basedmaterialsbyweldingwithfillmaterialsthatare

metal-matrixcompositesgeneratedbySHS.Incontrast,the

goalofthisresearchistoutilizetheheatgeneratedfrom

theSHSprocesstobonddissimilarmaterialsinsitu,while

formingthemetal-matrixcompositethatisthebondma-

terial.

Thematerialstobebondedarealuminaceramic(Al2O3)

andtitaniummetal.TheSHSsystemchosentoformthe

bondisthecombinationoftitanium,aluminum,andboron

powders.TheSHSreactionofthesepowdersresultsinTiB2precipitatinginamatrixofTiAl,Ti3Al,orAl.Theconcept

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不同温度下DD6_单晶高温合金的燃气热腐蚀行为研究

不同温度下DD6_单晶高温合金的燃气热腐蚀行为研究

装 备 环 境 工 程 第20卷 第12期

·20· EQUIPMENT ENVIRONMENTAL ENGINEERING 2023年12月

收稿日期：2023-10-29；修订日期：2023-12-11

Received：2023-10-29；Revised：2023-12-11 引文格式：杨丽媛, 张骐, 孙志华, 等. 不同温度下DD6单晶高温合金的燃气热腐蚀行为研究[J]. 装备环境工程, 2023, 20(12): 20-25. YANG Li-yuan, ZHANG Qi, SUN Zhi-hua, et al. Hot Gas Corrosion Behavior of Single Crystal Superalloy DD6 at Different Temperature[J]. Equipment Environmental Engineering, 2023, 20(12): 20-25.

不同温度下DD6单晶高温合金的

燃气热腐蚀行为研究

杨丽媛，张骐，孙志华，刘明，赵明亮

（北京航空材料研究院 航空材料先进腐蚀与防护航空科技重点实验室，北京 100095）

摘要：目的 研究DD6高温合金在650、800、950 ℃等3种典型温度的燃气热腐环境下的耐腐蚀性能。

方法 采用X射线衍射（XRD）、扫描电镜（SEM）、能谱仪（EDS）等测试方法，研究不同温度下DD6

高温合金的热腐蚀行为。结果与结论 随着温度的升高，合金的腐蚀速率呈逐渐增加的趋势。当温度为650、

800 ℃时，合金的腐蚀速率较小；当温度为950 ℃时，表面腐蚀产物明显剥落，腐蚀程度明显增加。在650 ℃

下，DD6合金的腐蚀层较薄，主要为NiO、Al2O3等氧化物。在800、950 ℃下，腐蚀层分为2层，外层由2

部分构成，最外侧为一薄层NiO和Co3O4等的混合物，次外层为相对疏松的NiO，内层为Al2O3和Cr2O3构

Effects of annealing treatment on the microstructure and mechanical properties

Effects of annealing treatment on the microstructure and mechanical properties

Effectsofannealingtreatmentonthemicrostructureandmechanicalproperties

oftheAlN–SiC–TiB2ceramiccompositespreparedbySHS–HIP

LijuanZhoua,⇑,HongboLib,YongtingZhengb

aSchoolofMaterialsScienceandEngineering,ShandongUniversityofTechnology,ZiBo255049,PRChinabCenterforCompositeMaterialsandStructures,HarbinInstituteofTechnology,Harbin150001,PRChina

articleinfo

Articlehistory:Received14July2012Receivedinrevisedform10November2012Accepted12November2012Availableonline20November2012

Keywords:AlN–SiC–TiB2ceramicAnnealingtreatmentMicrostructureMechanicalpropertiesabstract

Annealingtreatmentswerecarriedoutatdifferenttemperatures(600–1200°C)forvariousholdingtimes(2–10h)toevaluatethemicrostructuralandmechanicalpropertieschangesoftheAlN–SiC–TiB2ceramiccompositespreparedbySHS–HIP.Theexperimentalresultsshowthattheannealingtreatmentisbene-ficialtoimprovethemechanicalproperties.Inthemeantime,thedesolutionofSiC-richsolidsolutionandprecipitationoffineTiB2grainsoccurred.DuetotheprecipitationstrengtheningbytheSiC-richsolidsolutionandthegrainboundarystrengtheningbyfineTiB2particles,theimprovementofthemechanicalpropertieswasobviouswithhigherannealingtemperaturesandlongerholdingtimes.ThehighestHRA,bendingstrengthandfracturetoughnesswere94.1,517.5MPaand5.79MPam1/2,respectively,aftertheannealingtreatmentat1200°Cfor10h.Ó2012ElsevierB.V.Allrightsreserved.

专业单词-贮氢合金

专业单词-贮氢合金

第一部分

1 electrolyte 电解液，电解质，电解 2 electrode 电极

3 alloy electrode 合金电极 4 Elemectrochemical properts 电化学性能

5盖板cover board 铪(Hf) hā 6底板solepiece

7钢珠steel ball 8压钢珠press steel ball

9防爆阀valve preventing explosion 10大电流(倍率)放电discharge in high rate

current

11标称电压Normal voltage 12标称容量normal capacity

13放电容量discharge capacity 14充电上限电压limited voltage in

charge

15放电下限电压terminating voltage in discharge 16恒流充电constant current

charge

17恒压充电constant voltage charge 18恒流放电constant current discharge

19放电曲线discharge curve 20充电曲线charge curve

21放电平台discharge voltage plateau 22容量衰减capacity attenuation

23起始容量initial discharge capacity 24流水线pipelining

25传送带carrying tape 26焊极耳welding the current collector

27卷绕wind 28叠片layer

访学申请信等

访学申请信等

访学申请信

School of Materials Science and Engineering

Xi’an University of Architecture and Technology

235 Jiandong Street

Xi’an, Shaanxi 710055

P. R. China

18 January, 2012

Professor William?Lee

Department of Materials

Imperial College London

South Kensington Campus

London SW7 2AZ

UK

Dear Professor Lee,

I am writing to inquire about the possibility of my studying and researching in your lab for twelve months as a

visiting scholar. While preparing for my application to China Scholarship Council/ Since my application to China

Scholarship Council has been approved, I would like to express my strong interest in joining your research group and

collaborating in your scholarly work.

I am a professor in School of Materials Science and Engineering, Xi’an University of Architecture and

Technology here in China, and my research interest is mainly on refractories. I got my Bachelor’s degree in

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