本文以民用大飞机蒙皮用TC4钛合金材料为实验对象, 进行了不同切割气体和切割参数下, 1.6 mm厚度TC4板材的激光切割实验, 并对切割的表面质量和相变区进行了检测。研究发现, Ar切割表面呈现白亮的金属色泽, N2切割表面呈现黑灰色; 切割缝附近的相变区由重熔区和热影响区组成, 相同参数条件下, N2切割表面粗糙度小于Ar切割表面粗糙度, 但Ar切割相变区深度小于N2切割相变区, 激光热输入是影响相变区深度的主要因素; 同种切割气体气氛下, 板材下表面附近的相变区深度大于上表面附近的相变区深度。

In this paper, Titanium alloy-TC4 for civilian large aircraft skins is used as the experimental object. Laser cutting experiments of 1.6 mm thickness TC4 sheet under different cutting gases and cutting parameters are performed, and the surface quality and heat affected zone are tested. The research found that Ar cutting surface showed a bright white metal luster, and N2 cutting surface appeared black and gray. The phase change zone near the cutting seam consists of a remelting zone and a heat affected zone. Under the same parameters, N2 cutting surface roughness is less than Ar cutting surface roughness, but N2 cutting phase change zone is larger than Ar cutting, and laser heat input is the main factor affecting the depth of the phase change zone; under the same cutting gas atmosphere, the depth of the phase change zone near the lower surface of the sheet is greater than the depth of the phase change zone near the upper surface.