电加工8418钢的能量分配与表面粗糙度模型

针对电火花加工8418钢构建一种采用不同电极材料加工时的表面粗度模型。采用实验与有限元仿真分析相结合的手段,首先通过实验分别得到紫铜电极、CuW70电极加工8418钢的表面粗糙度Ra,然后采用ANSYS软件仿真分析单脉冲放电加工8418钢的电蚀凹坑半径与深度,结合表面粗糙度模型计算出仿真Ra,通过对比实验得到的表面粗糙度Ra,分析得出紫铜电极、CuW70电极加工8418钢时工件上的能量分配系数η分别为33%和24%。最后对能量分配系数和表面粗度模型进行了实验验证,通过误差分析,不同电极加工的表面粗糙度最大误差为9.59%,证明了能量分配系数和表面粗度模型是准确的。通过对比实验和分析结果,得出不同电极材料对能量分配系数的影响,同时随着脉冲放电能量的增加,η对凹坑半径与深度的影响增大,采用紫铜电极与CuW70电极加工8418钢时Ra差异增大。

Energy Distribution and Surface Roughness Model in EDM of 8418 Steel

The surface roughness model in EDM of 8418 steel machined by different electrode materials was established.By combination of experimental method and simulation analysis, surface roughness of 8418 steel was experimentally obtained from copper electrode and CuW70 electrode.Then the diameter and depth of single erosive crater was simulated by ANSYS software, and the surface roughness was calculated based on surface roughness model.By analyzing experimental and simulated roughness, energy distribution coefficient (η) of copper electrode and CuW70 electrode in EDM of 8418 steel could be obtained, which were 33% and 24%, respectively.Finally, energy distribution coefficient and surface roughness model were verified by a series of EDM experiments.The maximum error of surface roughness with different electrode materials was 9.59% by error analysis.It proved that energy distribution coefficient and surface roughness model were accurate.By comparing the experimental and analytical results, the effect of electrode material on energy distribution coefficient could be obtained.The effect of energy distribution coefficient η on the diameter and depth of erosive crater was enhanced with increasing discharge energy.Therefore, the difference between surface roughness using the copper electrode and CuW70 electrode became obvious.