哈尔滨工业大学工学博士学位论文
目录
摘要 ............................................................................................................................... I Abstract............................................................................................................................ I II
第1章绪论 (1)
1.1 研究背景和意义 (1)
1.2 常规FSSW研究进展 (2)
1.2.1 界面形貌与微观组织 (2)
1.2.2 材料流动行为 (6)
1.2.3 焊具设计与工艺优化 (7)
1.3 回填式FSSW研究进展 (8)
1.3.1 焊点成形 (10)
1.3.2 焊接热循环与微观组织 (11)
1.3.3 焊接工艺与接头力学性能 (12)
1.4 本文研究内容 (13)
第2章试验材料与研究方法 (15)
2.1 试验材料及设备 (15)
2.1.1 试验材料 (15)
2.1.2 试验设备 (17)
2.2 焊接试验方法 (18)
2.2.1 常规FSSW试验 (18)
2.2.2 点固式FSSW试验 (19)
2.2.3 回填式FSSW试验 (19)
2.3 微观组织分析 (19)
2.3.1 光学显微镜分析 (19)
2.3.2 扫描电镜分析 (20)
2.3.3 透射电镜分析 (20)
2.4 力学性能测试 (20)
2.4.1 拉剪性能测试 (20)
2.4.2 显微硬度测试 (21)
2.5 焊接热循环测量 (21)
目录
第3章不同FSSW方法对比试验研究 (23)
3.1 引言 (23)
3.2 带匙孔FSSW研究 (23)
3.2.1 常规FSSW (23)
3.2.2 点固式FSSW (28)
3.3 回填式FSSW研究 (32)
3.3.1 对称回填式FSSW (32)
3.3.2 非对称回填式FSSW (40)
3.4 本章小结 (46)
第4章非对称回填式FSSW温度场及流场研究 (48)
4.1 引言 (48)
4.2 数值分析模型的建立 (48)
4.2.1 刚-塑性有限元控制方程 (48)
4.2.2 几何模型及网格划分 (50)
4.2.3 材料模型及边界条件 (51)
4.2.4 摩擦模型 (53)
4.2.5 模型验证 (54)
4.3 模拟结果及分析 (56)
4.3.1 焊接温度场及热循环 (56)
4.3.2 材料流动行为 (65)
4.3.3 材料变形行为 (66)
4.4 焊点形貌及微观组织预测 (69)
4.4.1 焊点形貌预测 (69)
4.4.2 微观组织预测 (70)
4.5 本章小结 (71)
第5章非对称回填式FSSW焊点形貌特征及微观组织演变规律 (73)
5.1 引言 (73)
5.2 焊点形貌特征及形成机制 (73)
5.2.1 搅拌套扎入深度对焊点形貌的影响 (73)
5.2.2 焊具转速对焊点形貌的影响 (75)
5.2.3 搅拌套运动速率对焊点形貌的影响 (77)
5.3 接头微观组织演变规律及形成机制 (79)
5.3.1 共晶组织及液化裂纹 (79)
哈尔滨工业大学工学博士学位论文
5.3.2 晶粒形态 (84)
5.3.3 位错及沉淀相 (88)
5.4 本章小结 (97)
第6章非对称回填式FSSW接头力学性能及工艺优化 (99)
6.1 引言 (99)
6.2 非对称回填式FSSW接头力学性 (99)
6.2.1 显微硬度分布特征 (99)
6.2.2 拉剪性能变化规律 (102)
6.3 非对称回填式FSSW工艺优化 (110)
6.3.1 优化方法与试验设计 (110)
6.3.2 响应模型的建立及其精度分析 (112)
6.3.3 工艺参数优化 (114)
6.3.4 优质接头形成机制 (115)
6.4 本章小结 (116)
结论 (118)
创新点 (120)
参考文献 (121)
攻读学位期间所取得的研究成果 (132)
哈尔滨工业大学学位论文原创性声明和使用权限 (134)
致谢 (135)
个人简历 (136)
Contents
Contents
Abstract (In Chinese) ...................................................................................................... I Abstract (In English)..................................................................................................... I II
Chapter 1 Introduction (1)
1.1 Background and significance of research (1)
1.2 Research status of conventional FSSW (2)
1.2.1 Interface morphologies and microstructures (2)
1.2.2 Material flow behavior (6)
1.2.3 Welding tool design and process optimization (7)
1.3 Research status of refilling FSSW (8)
1.3.1 Weld forming (10)
1.3.2 Welding thermal cycles and microstructures (11)
1.3.3 Welding technology and mechanical properties of joints (12)
1.4 Main contents of research (13)
Chapter 2 Experimental materials and research methods (15)
2.1 Experimental materials and equipments (15)
2.1.1 Experiment materials (15)
2.1.2 Experiment equipments (17)
2.2 Welding processes (18)
2.2.1 Conventional FSSW (18)
2.2.2 Tacking FSSW (19)
2.2.3 Refilling FSSW (19)
2.3 Microstructure analyses (19)
2.3.1 Optical microscope observation (19)
2.3.2 Scanning electron microscope analysis (20)
2.3.3 Transmission electron microscope analysis (20)
2.4 Mechanical properties tests (20)
2.4.1 Tensile shear test (20)
2.4.2 Microhardness test (21)
2.5 Welding thermal cycle measurement (21)
Chapter 3 Experimental study of different FSSW processes comparison (23)
3.1 Introduction (23)
3.2 Studies of FSSW with key hole (23)
3.2.1 Conventional FSSW process (23)
哈尔滨工业大学工学博士学位论文
3.2.2 Tacking FSSW process (28)
3.3 Refilling FSSW process (32)
3.3.1 Symmetry refilling FSSW (32)
3.3.2 Asymmetric refilling FSSW (40)
3.4 Summary (46)
Chapter 4 Temperature characteristics and flow behaviors in asymmetric refilling FSSW (48)
4.1 Introduction (48)
4.2 Modeling for numerical simulation (48)
4.2.1 Rigid-plastic finite element governing equations (48)
4.2.2 Geometrical model and element meshing (50)
4.2.3 Material model and boundary conditions (51)
4.2.4 Friction model (53)
4.2.5 Model validation (54)
4.3 Simulation results and analyses (56)
4.3.1 Welding temperature field and thermal cycle (56)
4.3.2 Material flow behavior (65)
4.3.3 Material deformation behavior (66)
4.4 Predictions of weld morphologies and microstructures of joints (69)
4.4.1 Precipitations of macrostructures (69)
4.4.2 Predictions of microstructures (70)
Chapter 5 Weld morphology characteristics and microstructures evolutions in asymmetric refilling FSSW joints (73)
5.1 Introduction (73)
5.2 Weld morphology characteristics and formation mechanism (73)
5.2.1 Effect of sleeve plunging depth on weld morphologies of joints (73)
5.2.2 Effect of tool rotation speed on weld morphologies of joints (75)
5.2.3 Effect of sleeve motion rate on weld morphologies of joints (77)
5.3 Microstructure evolutions of joint and formation mechanism (79)
5.3.1 Eutectic structure and liquation crack (79)
5.3.2 Grain morphology (84)
5.3.3 Characteristics of dislocation and precipitates (88)
Chapter 6 Mechanical properties of joints and process optimization for asymmetric refilling FSSW process (99)
6.1 Introduction (99)
6.2 Mechanical properties of asymmetric refilling FSSW joints (99)
6.2.1 Microhardness distribution characteristics (99)
Contents
6.2.2 Tensile shear properties evolutions (102)
6.3 Process optimization for asymmetric refilling FSSW process (110)
6.3.1 Optimization method and experiment design (110)
6.3.2 Establishing and precision analysis for response surface model (112)
6.3.3 Optimization of technical parameters (114)
6.3.4 Formation mechanism of high quality joint (115)
6.4 Summary (116)
Conclusions (118)
Innovation of the dissertation (120)
References (121)
Papers published in the period of Ph.D. education (132)
Statement of copyright and letter of authorization (134)
Acknowledgements (135)
Resume (136)