磁粉电火花连续脉冲放电毛化加工实验研究

Study on Continuous Pulse Discharge Machining of Magnetic Powder EDM

为解决传统电火花毛化工具电极不能适应复杂形貌的狭缝、沟槽或内表面的问题,提出了一种由磁铁吸引金属粉末形成的柔性磁粉工具电极,基于自主搭建的磁粉电火花毛化加工系统在镀镍铜板样件上进行实验,研究了连续脉冲放电加工过程中的实验参数对表面加工质量和粗糙度值的影响。实验结果表明,柔性的磁粉电极可以用于毛化具有复杂形貌的狭缝、沟槽等表面,毛化表面的粗糙度值(Ra与Rz)与峰值电流、脉冲宽度、磁粉颗粒径和加工持续时间等参数均呈正相关。其中,峰值电流对粗糙度的影响最大,Ra增幅达到133.3%,Rz增幅也达到83.7%。但是占空比的大小对粗糙度值的增长影响不大,Ra增幅仅为5.8%,Rz增幅仅为4.8%。另外,通过响应曲面法的研究结果可知,影响毛化表面粗糙度值(Ra与Rz)的强弱排序为:峰值电流、脉冲宽度、磁粉粒径、加工时间。

To solve the problem that the traditional EDM texturing tool electrode cannot adapt to complex morphologies,such as slits,grooves or inner surfaces,a flexible magnetic powder tool electrode formed by a magnet attracting metal powder was fabricated to be utilized on a nickel-plated copper plate sample based on a self-built magnetic powder electric spark texturing system,which aimed to study the influence of continuous pulse electric discharge machining parameters on machining quality and the surface roughness value.The experimental results show that the flexible magnetic powder electrode can be used to texture the surface of slits and grooves with complex morphology,and the roughness value(Ra and Rz)of the textured surface is positively correlated with parameters such as peak current,pulse width,magnetic particle diameter and processing duration.Among them,the peak current has the greatest impact on roughness,with Ra increasing by 133.3%and Rz increasing by 83.7%.However,the size of the duty cycle has little effect on the increase of the roughness value,in which the increase of Ra is only 5.8%and Rz is only 4.8%.In addition,according to the result of the response surface method,it can be seen that the order of strength that affects the roughness value(Ra and Rz)of the textured surface is peak current,pulse width,magnetic particle size,and processing time.