钛合金激光焊接接头塑性损伤行为分析  

Analysis on plastic damage evolution of laser welded joint of titanium alloy

作　　者：张建勋[1] 宋旭[1] 董丽娜[1] 

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《焊接学报》2011年第5期1-4,113,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(50875200);国家教育部博士点基金资助项目(20070698088)

摘　　要：采用多试样拉伸法研究了TC4钛合金CO2激光深熔焊接接头的塑性损伤行为.结果表明,钛合金激光深熔焊接接头的塑性损伤过程表现为微孔洞的产生、长大与聚合方式;微孔洞体积分数沿焊接接头从焊缝、热影响区至母材呈非线性分布;焊接接头的微孔洞损伤规律和载荷大小相关,在载荷较小时焊缝的损伤大于热影响区和母材损伤,随着载荷值的增加,热影响区的孔洞体积分数的增长速度比焊缝快,当载荷增加到一定程度,热影响区和母材的损伤程度要大于焊缝;焊缝区晶粒尺寸变化对其塑性损伤影响很小,但其递降梯度有延缓其塑性损伤的作用.The damage evolution of TC4 titanium alloy welded joint by CO2 laser deep penetration welding was investigated with multi-specimens method.The research results show that the plastic damage evolution shows the process of the initiation,growth and coalescence of the micro-voids.The volume fraction of micro-voids nonlinearly distributed from the weld metal and HAZ to the base metal.The plastic damage evolution of the joint by laser welding has a relationship with the load.The plastic damage in weld metal is greater than that in base metal and HAZ at the lower load,but the volume fraction of micro-voids in HAZ will increase faster than that in weld metal with the load being increased,and the damage in the heat affected zone and base metal is greater than the weld when the load increases enough.The grain size in welded joint has little effects on the plastic damage,but the gradient of the grain size may delay the plastic damage of the welded joint by laser welding.

关 键 词：激光焊 塑性损伤 TC4钛合金 

分 类 号：TG456.7[金属学及工艺—焊接]