形状记忆合金YAG激光焊接

YAG Laser Welding of Shape Memory Alloy

采用YAG激光焊机对TiNi形状记忆合金板材进行焊接性研究。通过大量工艺试验确定合适的激光工艺参数范围。分别对焊接接头各部分微观组织特点、组织结构、记忆性能、抗拉强度进行了研究。研究发现,焊缝组织晶粒粗大,有新相Ni3Ti的析出;焊接热影响区较窄;焊接接头的形状恢复率是母材的97.4%;母材抗拉强度为1155MPa,焊接接头抗拉强度达798MPa,是母材抗拉强度的69%,断裂部位在焊缝中心。

With high energy YAG Laser beam method, the weld ability of the TiNi shape memory alloy sheet was studied. The relationship among parameters and its proper adjusting range are acquired. Thus the range of the parameters used in the engineering application was obtained. Some characteristics such as phase, microstructure, shape memory strength of the welded joint were discussed. Results show that the crystal grain in welded joint is large, a propert nd ies and tensile phases such as Ni3 Ti separate out. Furthermore, the welding heat affected zone is narrow,and the welded joint shape recovery rate is 97.4 of the parent metal and the parent metal tensile strength is 1155MPa. The tensile strength of welded joint reaches 798 MPa which is 69 % of the parent metal and the fracture appears in the center of weld.