多阶模半导体激光增材制造工艺参数对熔覆层残余应力影响的数值模拟

Numerical Simulation on the Influence of Process Parameters on Residual Stress in Cladding Layer by Multi-mode Semi-conductor Laser Additive Manufacturing

为了研究多阶模半导体激光增材制造工艺参数对熔覆层残余应力的影响,利用ANSYS软件构建了单道熔覆层模型,运用生死单元法加载多阶模半导体激光为热源。采用正交试验法展开了工艺参数对熔覆层宽度与高度方向应力场分布规律的影响研究。结果表明:熔覆层宽度方向上的应力场左右对称并在中心处有明显的“平台效应”,体现了多阶模激光热源热量分布均匀的特点;熔覆层高度方向上,应力值沿熔覆层高度方向逐渐增大,直到熔覆层顶部达到最大值;工艺参数对残余应力的影响次序为:送粉速率>扫描速度>激光功率;当采用优化工艺参数计算时,熔覆层高度及宽度上的最大应力为196.53MPa和98.22MPa,有效地降低了残余应力值,为多阶模半导体激光增材制造中的残余应力调控提供了参考。

In order to study the influence of process parameters by multi-mode semiconductor laser additive manufacturing on the residual stress field of the cladding layer,ANSYS software was used to build a single-track cladding layer model.The multi-mode semiconductor laser heat source was loaded by using the life-and-death element method.Orthogonal experiment was used to study the influence of process parameters on the stress field distribution in the width and height of the cladding layer.The results show that the stress field along the width of the clad layer is symmetrical on both sides and has obvious platform effect at the center,which reflects the heat of multi-mode laser is average;In the height direction of the cladding layer,the stress increases gradually along the height until the surface of the cladding layer reaches the maximum value;The effect order of process parameters on residual stress is:powder feeding rate>scanning speed>laser power;The maximum stress on the width and height direction of the clad layer is 196.53MPa and 98.22MPa when the optimal process parameters are adopted,which greatly reduces the value of residual stress and provides a reference for controlling residual stress in cladding layer by multi-mode semi-conductor laser additive manufacturing.