Study on Microstructure and mechanical properties of 1.5mm Ti-6Al-4V titanium alloy laser welded joint

Keywords:Ti-6Al-4V titanium alloy / laser welding / microstructure / mechanical properties

Authors: Fu Heguo, Liu Guangxin, Xie Hongzhi, Jiang Wentong, etc

Shenyang Aircraft Industry Group Co., Ltd

Source: welding and cutting

Abstract: the experiment of laser welding + surface modification welding of 1.5mm Ti-6Al-4V titanium alloy was carried out, and the microstructure and static properties of the joint were observed. The results show that due to the influence of different welding thermal cycles, The structure area of laser welding + surface modification welding joint can be divided into a base metal area, heat affected area, equiaxed crystal area at the bottom of weld, and columnar crystal area at the top of the weld, there is widmanstatten structure in the weld structure, With the increase of the distance from the fusion line, the microstructure of the heat-affected zone increases α' The volume fraction decreased gradually.

The mechanical properties of the joint show that the tensile strength and shear strength are equivalent to the base metal, and the minimum bending angle is 35 °, indicating that the joint can be applied in engineering.

Morphology of Ti-6Al-4V titanium alloy weld joint

Microstructure of weld zone

Microstructure morphology of different regions in heat affected zone

Test value of mechanical properties of joint

The average value of mechanical properties of joint