Cu-Ni-Sn合金精加工表面残余应力有限元仿真研究

Finite Element Simulation of Residual Stress on Finishing Surface of Cu-Ni-Sn Alloy

为研究Cu-Ni-Sn合金精加工后表面残余应力层深分布及大小,根据室温和高温下Cu-Ni-Sn合金流动应力—应变曲线数据,构建了试验条件下Cu-Ni-Sn合金的J-C本构模型,采用有限元分析法研究了切削参数和刀具几何角度对Cu-Ni-Sn合金加工表面残余应力的影响规律,并采用正交试验法和极差分析法对表面残余应力进行了优化分析。分析结果表明:Cu-Ni-Sn合金精车加工后,表层残余应力呈现“勺型”分布,表层残余拉应力沿深度方向转变为压应力;表层最大残余拉应力和最大残余压应力与切削速度和切削深度呈正相关,最大残余拉应力随刀具前角增大而减小;表层残余拉应力与最大残余压应力随刀具后角的增大而减小;采用正交试验法和极差分析法得到对表层最大残余拉应力的影响显著性排序为切削速度>刀具前角>刀具后角>切削深度。

In order to study the depth distribution and size of residual stress layer on the surface of Cu-Ni-Sn alloy after finishing machining,J-C constitutive model of Cu-Ni-Sn alloy under experimental conditions is constructed according to the flow stress-strain curve data of Cu-Ni-Sn alloy at room temperature and high temperature.The influence of cutting parameters and tool geometry angle on the surface residual stress of Cu-Ni-Sn alloy is studied by finite element analysis,and the residual stress is optimized by orthogonal test and range analysis.The results show that the surface residual stress of Cu-Ni-Sn alloy presents a spoon-shaped distribution after finishing machining,and the surface residual tensile stress changes to compressive stress along the depth direction.The maximum residual tensile stress and compressive stress on the surface are consistent with the change of cutting speed and cutting depth,and the maximum residual tensile stress decreases with the increase of tool angle.The surface residual tensile stress and maximum residual compressive stress decrease with the increase of tool angle.Orthogonal test method and range analysis method are used to get the significance order of the influence on the maximum residual tensile stress on the surface,which is as follow:cutting speed>tool rake angle>angle of backing-off>depth of cutting.