激光叠焊接头显微组织及力学性能分析

Analysis of microstructure and mechanical properties of laser welded lap joints

摘要: 采用OM,SEM分析了TC4钛合金激光叠焊接头各部分显微组织特征,研究了接头力学性能.结果表明,TC4钛合金激光叠焊接头显微组织由焊缝及热影响区组成,焊缝为针状马氏体α'交织成的网篮状组织.0.8 mm厚TC4钛合金薄板激光叠焊最佳工艺参数为功率1800~2350 W,焊接速度为1.5~2.5 m/min,此时拉伸试样平均单位长度焊缝承载力为458 N/mm,连接焊缝最大抗剪强度达732 MPa.拉伸过程焊缝截面轴线偏转角θ与接头承载能力相关,θ角越大,接头承载能力越强。

Abstract: Microstructure and mechanical properties of laser lap weld joints of TC4 alloy are investigated.Experimental results show that the microstructure of joints is martensite α' crossed into basket shape in fusion zone.The average bearability of weld bead is 458 N/mm, and the maximal shear strength of interface is up to 732 MPa when the optimum parameters of laser lap welding for 0.8 mm thick TC4 sheet are P from 1800 to 2350 W and v from 1.5 to 2.5 m/min.The deflexion angle of joints is related to the bearability of weld joints, the bigger deflexion angle the better bearability of weld joints.