TC4合金相变超塑性扩散连接接头组织与性能研究  

Study on Microstructure and Properties of TC4 Alloy Phase Transformation Superplastic Diffusion Bonding Joint

作　　者：唐婷婷 林鹏[1,2] 池成忠 郝永刚[1] 

机构地区：[1]太原理工大学材料与科学工程重点实验室,山西太原030024 [2]太原理工大学先进镁基材料山西省重点实验室,山西太原030024

出　　处：《热加工工艺》2018年第1期41-44,48,共5页Hot Working Technology

基　　金：国家自然科学基金资助项目(51505323)

摘　　要：在非真空条件下对TC4合金进行了恒温超塑性扩散连接及相变超塑性扩散连接。采用莱卡尔金相显微镜、扫描电镜（SEM）及电子万能试验机分别对接头的显微组织、性能及断裂机理进行了研究分析。结果表明,在非真空条件下,TC4/TC4相变超塑性扩散连接接头焊合区界面处Ti和O形成的氧化膜在高温高压下可被破坏,O元素向基体中扩散,其分布均匀,说明TC4合金在非真空条件下进行相变超塑性扩散连接是可行的。与950℃恒温超塑性扩散连接相比,TC4合金在850℃～950℃相变超塑性扩散连接所获得的接头质量更优,界面处晶粒尺寸较小,剪切强度也较高,达到612 MPa,接头断裂方式为韧性断裂。这说明相变可提高原子扩散速率,改善连接质量,并实现低温扩散。The isothermal superplastic diffusion bonding and phase transformation superplastic diffusion bonding of TC4 alloy under non vacuum condition were carried out. The microstructure, properties and fracture mechanism of the joint were studied by using Lekal metallurgical microscope, scanning electron microscope （SEM） and electronic universal testing machine. The results show that the oxidation film formed by Ti and O elements at the bonding interface of TC4/TC4 phase transformation superplastic diffusion bonding joint is destroyed under non vacuum condition, O element diffuses into the matrix and the distribution is uniform. This indicates that TC4/TC4 alloy phase transformation superplastic diffusion bonding is feasible. Compared with the isothermal diffusion bonding of TC4 alloy at 950℃, the quality of TC4 joint obtainded by phase transformation superplastic diffusion bonding in 850 ℃ -950℃ is better, and the grain size at the interface is smaller, the shear strength is higher, which is up to 612 MPa, and the joint fracture mode is ductile fracture. This shows that the phase transformation can increase the rate of atomic diffusion, improve the quality of connection and realize low temperature diffusion.

关 键 词：TC4合金 恒温超塑性扩散连接 相变超塑性扩散连接 

分 类 号：TG406[金属学及工艺—焊接]