【摘要】 为探讨超声水雾中第二次切割的加工参数对模具钢Cr12MoV表面粗糙度和切割速度的影响规律,在往复走丝线切割加工中,计划采用一种多介质的多次切割新工艺,即第一次切割在乳化液中进行,第二次切割在超声水雾中,第三次切割在大气中。实验采用单因素法,分析了脉冲宽度、峰值电流、工件厚度、偏移量、水雾量和工作台进给速度对表面粗糙度和切割速度的影响规律;借助中心复合法的建模优势及Design-Expert软件绘制三维响应曲面图的功能,建立了精度较高的线切割精加工表面粗糙度和切割速度的回归模型公式,经过实验验证表面粗糙度的实测值和预测值的相对误差最高为3.56%,切割速度的实测值和预测值的相对误差最高为-8.68%;由回归方程方差分析结果可知,工作台进给速度和脉冲宽度对表面粗糙度的影响非常显著,工作台进给速度对切割速度的影响非常显著。更多还原

【Abstract】 In order to investigate the influences of the WEDM parameters for the second cutting of Cr12MoV die steel in ultrasonic water mist on the surface roughness and the cutting speed, a new procedure was adopted, i.e. WEDM in multimedium and multiple cutting, in which the first cutting was in emulsified liquid, the second cutting was in ultrasonic water mist, while the third cutting was in atmosphere. By means of single factor method, the effects of the pulse duration, peak current, workpiece thickness, offset, water mist amount and worktable feed speed on the surface roughness and the cutting speed were analyzed. By virtue of the advantage of central composite design for modeling and the features of Design-Expert software, the high-precision regression models of the surface roughness and the cutting speed in ultrasonic water mist during the second cutting were built. The experimental results show that the relative error between the measured value and the predicted value of the surface roughness is less than 3.56%. The relative error between the measured value and the predicted value of the cutting speed is less than-8.68%. According to the variance analysis of the regression equation, the influences of the worktable feed, pulse duration on the surface roughness are very significant, and the worktable feed has a significant effect on the cutting speed.更多还原