基于数值模拟的激光增材再制造薄壁件的工艺优化

Numerical Simulation of Process Optimization of Thin-Walled Components by Laser Additive Remanufactured

为探究工艺参数、扫描方式、坡口形状对激光增材再制造薄壁件的影响规律,基于ANSYS有限元分析软件,对激光增材再制造316L不锈钢薄壁件的温度场、应力场进行数值模拟分析。结果表明:激光功率、扫描速度过大或过小均会引起残余应力某一分量增大;选用垂直交叉扫描方式可以减小残余应力大小,但可能会引起修复区与基体结合区应力过大,导致裂纹的产生;通过比较两种坡口形状的应力分布,无棱边的坡口形状可以减小结合区的应力集中,并有效减小基板的变形量。最后设计试验,验证不同坡口形状对激光增材再制造试样质量的影响。试验结果表明,弧形相较梯形坡口形状,基材与修复区之间形成了良好的冶金结合,微观组织结构更均匀且硬度也有相应的提升,验证了仿真的正确性。

In order to explore the influence of process parameters, scanning method and groove shape on the thin-walled parts manufactured by laser additive manufacturing, based on the ANSYS finite element analysis software, the temperature field and stress field of the thin-walled 316L stainless steel thin-walled parts manufactured by laser additive manufacturing were analyzed by numerical simulation. The results show that a certain component of residual stress will increase if the laser power and scanning speed are too large or too small;the use of vertical cross-scanning method can reduce the residual stress, but it may cause excessive stress in the bonding area between the repaired area and the substrate. This leads to the initiation of cracks. Comparing the stress distribution of the two groove shapes, the edgeless groove shape can reduce the stress concentration in the bonding area and effectively reduce the deformation of the substrate, revealing that the substrate is deformed during the remanufacturing process. Deformation mechanism, and finally designed experiments to verify the influence of different groove shapes on the quality of laser additive remanufactured samples. The experimental results show that a good metallurgical bond is formed between the base material and the repaired area in the shape of the arc groove, which verifies the correctness of the simulation.