摘要
针对Ti2AlNb/Ti6Al4V异种金属激光焊接接头力学性能较差的问题,采用脉冲激光与光束偏移相结合的方法对Ti2AlNb/Ti6Al4V异种金属进行焊接。试验结果表明,当光束从Ti2AlNb侧移动到Ti6Al4V时,接头的熔化区组织由B2相转变为针状马氏体α’相,Ti6Al4V侧热影响区的完全相变区宽度明显增加,Ti2AlNb侧热影响区微观组织变化较小。同时熔化区区域的显微硬度从300 HV左右增加到410~420 HV,接头的拉伸强度增加到1017 MPa,伸长率增加到10.5%,断裂模式从脆性模式转变为延性模式。上述结果证明,脉冲激光与光束偏移的组合方法能够使接头具有更高的冷却速度,从而在熔化区形成针状马氏体α’组织,提高了接头的力学性能。
Aiming at the poor mechanical properties of laser welded joint of Ti2AlNb/Ti6Al4V dissimilar titanium alloys,the combination of pulsed laser welding and laser offset was used to weld Ti2AlNb/Ti6Al4V dissimilar alloys.The results show that when the laser beam moves from Ti2Al Nb side to Ti6Al4V side,the microstructure in the fusion zone transforms form B2 phase to acicularα’phase and the width of complete phase transformation zone increases significantly in the heat affected zone at Ti6Al4V side,but the microstructure of heat affected zone at Ti2AlNb side changes little.Meanwhile the microhardness of the fusion zones increases from around 300 HV to 410-420 HV,the tensile strength of the joint increases to1017 MPa,the elongation of the joint raises to 10.5%,and the fracture mode of the joint transforms from brittleness mode to ductility mode.The above result shows that the combination of pulse laser and laser beam offset can increase the cooling speed of welded joints,thus acicular martensiteα’forms in the fusion zone,which can improve the mechanical properties of the welded joint.
作者
余浩魁
高晓龙
李思阳
李伦坤
王小强
YU Haokui;GAO Xiaolong;LI Siyang;LI Lunkun;WANG Xiaoqiang(Insititute of Mechanical Engineering,Baoji University of Arts and Sciences,Baoji 721016,China)
出处
《热加工工艺》
北大核心
2020年第15期19-24,共6页
Hot Working Technology
基金
国家自然科学基金项目(51705005)
宝鸡文理学院创新科研项目(YJSCX19ZD05,YJSCX19ZC10)。
