超弹性NiTi记忆合金丝激光焊接接头组织与性能研究  

Research for Microstructures and Properties of Laser Welded Joint of Superelastic NiTi Alloy Wire

作　　者：张怡[1] 王宇[1] 叶晶[1] 邱宇晨 冯俊华 

机构地区：[1]西安石油大学材料科学与工程学院,陕西西安710065 [2]湖南埃普特医疗器械有限公司,湖南湘乡411400

出　　处：《热加工工艺》2014年第5期27-30,共4页Hot Working Technology

基　　金：中国石油科技创新基金项目(2012D-5006-0607);陕西省材料加工重点学科项目(YS30230203);西安石油大学青年科技创新基金项目(2011BS005)

摘　　要：采用脉冲激光焊对Ti-56.04at%Ni合金细丝进行激光焊接研究,对比分析接头与母材的显微组织、断口形貌、耐蚀性、形变恢复率及应力-应变曲线的变化。结果表明:当NiTi合金用做功能材料时,激光焊接是可取的;激光焊接接头熔化区由树枝晶组成,热影响区为柱状晶,母材部分为细小等轴晶;激光焊接接头耐蚀性比母材好;焊接接头的恢复率可达母材的92%;接头抗拉强度可达母材的84%,接头的断裂位置在热影响区,激光焊接接头与母材均为韧性断裂。Ti-56.04%Ni（atom fraction）wires were welded using pulsed YAG laser. The laser welded joint were tested for the microstructure, fractured appearance, corrosion resistance, shape recoverable ratio and stress-strain curves in comparison with the base metal. The results show that laser welded joint NiTi alloy is advisable when NiTi alloy is used as functional materials. The melted pool features dendrite structure, the microstructures of HAZ is columned crystal, The base metal is made of fine equiaxial crystals; Corrosion resistance of laser welded joint are better than base metal; The shape recoverable ratio of laser welded joint is up to 92% of the base metal; The ultimate tensile strength of the joint is up to 84% of the base metal; the flacture appears in the HAZ, Laser welded joint and base metal are both ductile fi＇acture.

关 键 词：NITI形状记忆合金 激光焊接 组织 性能 

分 类 号：TG142.75[一般工业技术—材料科学与工程] TG456.7[金属学及工艺—金属材料]