放电参数对短电弧铣削TC4加工性能影响的研究

Study on the effects of short electric arc milling on TC4 machining performance

短电弧加工技术(SEAM)是一种实现难加工导电材料高效去除的新型放电加工方法。采用不同电极材料,开展钛合金TC4短电弧铣削加工试验,探究在不同放电参数(电压、频率和占空比)下对加工过程中材料去除率(MRR)、相对电极相对损耗率(RTWR)的影响规律;并进一步分析工件宏微观形貌、元素变化及硬度测定。试验表明:影响MRR和RTWR的因素为脉冲电压>脉冲占空比>脉冲频率;紫铜电极具有高的材料去除率和好的表面质量;加工后表面存在重铸层、熔滴和微孔等结构;其表面显微硬度由重铸层向基体逐渐降低,并在距离工件表面深度90μm处趋于稳定。由此证明,金属电极材料更适合SEAM加工钛合金材料,这为后续SEAM加工钛合金零部件提供了理论依据。

Short electric arc milling(SEAM)is a new type of discharge machiningmethod to efficiently remove difficult-to-machine conductive materials.Different electrode materials were used to carry out short electric arc milling experiments on titanium alloy TC4,and the influences of different discharge parameters(voltage,frequency,duty ratio)on material removal rate(MRR)and relative tool wear rate(RTWR)during machining were explored.Furthermore,the macro and micro morphology of the workpiece,the change of elements and the determination of hardness are analyzed.The experimental results shows that the factors affecting MRR and RTWR is pulse voltage,pulse duty ratio,pulse frequency.Copper electrode has high material removal rate and good surface quality.There are recast layer,droplet and micropore structures on the machined surface.The surface microhardness decreases gradually from the recast layer to the substrate,and tends to be stable at 90μm from the workpiece surface depth.It is proved that metal electrode materials are more suitable for SEAM processing titanium alloy materials,which provides a theoretical basis for SEAM processing titanium alloy parts in the future.