TA15钛合金激光切割热影响区的组织与性能研究

Microstructure and Mechanical Properties of Laser Cutting Heat Affected Zone of TA15 Titanium Alloy

对不同厚度的TA15钛合金板材进行激光切割试验,研究了TA15钛合金板材热影响区的组织、深度,板材的拉伸性能及断口形貌。结果表明：热影响区可分为两部分,第一部分为激光切缝边缘的熔化区,第二部分为非熔化区,热影响区的组织由非熔化区向熔化区逐渐变大;从热影响区到基体显微硬度呈明显的下降趋势,板材下表面的热影响区深度均大于上表面的热影响区深度。与去除热影响区的板材相比,存在热影响区的板材的屈服强度和抗拉强度都有一定程度的下降;有无热影响区的试样断口形貌均是韧窝,属于塑性断裂。

The laser cutting experiments of TA15 titanium alloy sheets with different thicknesses were carried out, and the microstructure and depth of heat affected zone （HAZ）, tensile properties and fracture morphology of TA 15 titanium alloy sheet were studied. The results show that the HAZ can be divided into two parts, the first part is the melting zone at laser cutting edge, the second part is non melting zone. The microstructure of the HAZ gradually increases from the non melting zone to the melting zone. From the HAZ to the matrix, the microhardness decreases obviously, and the depth of the HAZ on the lower surface of the sheet is bigger than that on the upper surface. Compared with that of the sheet removing HAZ, the yield strength and tensile strength of the sheet with heat affected zone decrease to some extent. The fracture morphologies of the sample with or without HAZ are dimple, which belongs to plastic fracture.