表面处理对TC4钛合金激光焊接的影响

目的 为了提高TC4钛合金焊缝强度,满足实际生产的要求.方法 对TC4钛合金表面分别进行砂纸打磨、喷砂、涂覆石墨层以及激光扫描处理,然后采用2000 W光纤激光器对TC4钛合金进行拼接焊接实验.结果 对表面处理后的焊接焊缝熔深、抗拉强度进行了测试,结果表明,相对于未经过表面处理的焊缝熔深,采用表面处理后的焊缝熔深均增加了30％,焊缝抗拉强度均有增加,其中采用激光扫描处理后的焊缝抗拉强度达到最高的1106 MPa,超过了母材的抗拉强度.结论 激光扫描处理后,在材料表面形成的毛化现象,增加了材料对激光的吸收率,提高了焊缝的熔深,同时激光扫描过程中,未引入任何的杂质,不会产生裂纹及气孔,使焊缝的抗拉强度大于母材,满足实际生产要求.

Effect of Surface Treatment on Laser Welding of TC4 Titanium Alloy

The work aims to improve the weld strength of TC4 titanium alloy to meet the requirements of actual production. The surface of TC4 titanium alloy was sanded, sandblasted, coated with graphite layer and scanned by laser. Then, 2000 W fiber laser was adopted to conduct splicing and welding experiment on TC4 titanium alloy. The weld penetration and tensile strength after surface treatment were tested. Compared with the weld penetration without surface treatment, the weld penetration after surface treatment increased by 30%. The weld tensile strength also increased, and even the one scanned by laser reached to the highest of 1106 MPa, exceeding the tensile strength of the parent metal. After treatment by laser scanning, the material surface is roughed, which increases the absorption rate of the material for the laser, and improves the weld penetration. At the same time, there is no impurity in the laser scanning process and no cracks and pores are produced, so the tensile strength of the weld is greater than that of the parent metal, meeting the actual production requirements.