【摘要】 为了快速有效地提高气中电火花线切割加工Cr12MoV模具钢的表面质量,通过有限元法计算并分析了单脉冲气中火花放电条件下工件的温度场分布规律,获得了移动热源作用下工件表面电蚀坑形貌为半双椭球形,这与理想条件下电蚀坑形貌为半球形不同,进而探讨了移动热源作用下不同脉冲宽度对工件表面电蚀坑几何形貌的影响,并与试验结果进行了对比分析。结果表明,修正后电蚀坑深度与工件表面最大粗糙度变化趋势基本相同且数值非常接近,并得出修正前后电蚀坑的长度、宽度及深度随着脉冲宽度的增加不断增大的规律,然而电蚀坑尺寸增加使得电蚀坑体积不断增大,从而提高了气中电火花线切割加工效率,但降低了工件的表面质量。更多还原

【Abstract】 In order to quickly and efficiently improve surface quality of Cr12 Mo V in the process of WEDM in gas,temperature field distribution was calculated and analyzed through the finite element method under the conditions of single pulse spark discharge in gas. It turned out that electric erosion pit morphology of workpiece surface was half double ellipsoid under the moving heat source, which was different from hemisphere under the ideal condition. Furthermore, the effect of different pulse width on geometrical morphology of electric erosion pit of workpiece surface was discussed under the moving heat source, and the results were compared with experimental results. Results show that the change trend of the revised electric corrosion pit depth and maximum surface roughness of the workpiece is basically the same. It is concluded that length, width and depth of electric erosion pit increase with the increase of pulse width before and after the correction, but the increase of electric corrosion pit size makes electric corrosion pit volume increase. The machining efficiency of WEDM in gas is improved, but the surface quality of workpiece goes down.更多还原