电火花线切割大电流条件下电参数对加工性能的影响

Effect of Electrical Parameters on Machining Performance of WEDM Under High Current Conditions

为了解决往复走丝电火花线切割加工效率低的问题,对大电流条件下的两种电加工参数进行了研究,在保证平均电流相同的条件下,对小脉宽、大峰值电流和大脉宽、小峰值电流两种加工方式进行对比实验。结果表明:在普通往复走丝电火花线切割机床上,采用大脉宽、小峰值电流加工方式,其加工效率比小脉宽、大峰值电流的高约20%;采用小脉宽、大峰值电流的加工方式能有效地减少工件表面的烧伤,获得表面粗糙度值较小的加工表面。此外还分析了两种加工方式的放电加工机理,从放电通道扩展半径、放电频率和电极间放电状态等角度解释了两种方式的加工效率和表面质量差异。

Low processing efficiency is a bottleneck problem faced by reciprocating traveling type wire electrical discharge machining(WEDM)technology.In order to solve this problem,two kinds of electrical parameters of WEDM under high current condition are studied.Under the condition of ensuring the same average current,a comparative experiment is carried out on the two processing modes of small pulse width and large peak current and large pulse width and small peak current.The results show that the machining efficiency of conventional WEDM machine tool with large pulse width and small peak current is about 20%higher than that with small pulse width and large peak current.The processing method of small pulse width and large peak current can improve the quality of the machined surface,effectively reduce the burns on the workpiece surface,and obtain the machined surface with smaller surface roughness.On the basis of experiments,the discharge mechanism of the two machining modes is analyzed,and the differences of machining efficiency and surface quality between the two processing modes are explained from the angle of the discharge channel expansion radius,discharge frequency and interelectrode discharge state.