中文摘要：

采用纯Cu中间层,对TiNi形状记忆合金丝脉冲激光焊接进行研究。利用光学显微镜,扫描电镜,微区XRD等分析测试手段,研究了TiNi形状记忆合金丝激光焊接头的微观组织特点。为研究接头的力学性能和形状记忆效应,对其进行拉伸和弯曲试验。结果表明,焊缝区组织分布不均匀,不同形貌区域的成分差别较大,XRD分析焊缝区生成了B2,B19’,Ti3Ni4,Cu基固溶体及Cu与Ti的金属间化合物相CuTi,Cu4Ti3,Cu3Ti2,Cu3Ti等。TiNi形状记忆合金激光焊接头抗拉强度为489-536MPa,断口呈典型的韧-脆混合断裂特征。形状记忆恢复率达99%以上。

英文摘要：

YAG laser welding was used to join TiNi shape memory alloy thin wires with pure Cu as interlayer.The microstructural charactertics were investigated by means of optical microscopy,scanning electronic microscopy and micro-XRD et al.The tensile and bending tests were carried out to examine the mechanical properties and shape memory effect of the joint.Experimental results show that the joint has the heterogeneous microstructure and element distribution.B2,B19＇,Ti3Ni4,Cu solid solution and the intermetallic compounds,such as CuTi,Cu4Ti3,Cu3Ti2,Cu3Ti2,Cu3Ti were detected in fusion zone by XRD test.The laser-welded joint exhibits the ultimate strength of 489-536 MPa with ductile-brittle mixed fracture mode,and the shape recovery ratio reaches to 99%.