采用Nd:YAG激光和光纤激光焊接了Ti-50.7%Ni(原子分数)记忆合金,利用DSC,SEM和EDS对焊缝金属相变温度的变化规律和影响因素进行了分析,并对焊接接头的记忆功能进行了研究.结果表明,不同焊接工艺参数的焊缝金属与母材相比,相变温度有明显差异,产生差异的主要原因是组织的不同和基体Ni含量的差别.基体Ni含量与C,O,N的含量、富Ni沉淀相尺寸和数量以及焊接过程中Ni的烧损有关.低热输入、高激光功率密度的焊缝金属,基体Ni含量高,相变温度偏离母材的程度更大.焊缝金属相变温度的变化使得焊接接头形状恢复温度区间明显不同于母材,对其使用性能产生不利影响. Ti-50.7% Ni (atomic fraction) memory alloy was welded by Nd: YAG laser and fiber laser. The variation law of the phase transition temperature of the weld metal and its influencing factors were analyzed by DSC, SEM and EDS. Memory function.The results show that the phase transition temperature of the weld metal with different welding parameters is significantly different from that of the base metal, the main reason for the difference is the difference of microstructure and matrix Ni content.The matrix Ni content and C, O, N, the size and amount of Ni-rich precipitates and the burning of Ni in the welding process.The weld metal with low heat input and high laser power density has high Ni content and phase transition temperature from the base metal Larger.When the phase transition temperature of the weld metal changes, the temperature range of the shape of the welded joint is obviously different from that of the base metal, adversely affecting its serviceability.