Parametric study of ultrasonic-assisted hole sinking micro-EDM of titanium alloy
Parametric study of ultrasonic-assisted hole sinking micro-EDM of titanium alloy
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DOI：
10.1007/s00170-017-1051-1
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发表时间：
2018-02
期刊：
影响因子：
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通讯作者：
Param Singh;V. Yadava;A. Narayan
中科院分区：
文献类型：
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作者：
Param Singh;V. Yadava;A. Narayan
由于钛合金的导热性差、硬度高、与切削刀具材料的化学亲和性高，因此很难通过常规钻孔在钛合金中制造可接受公差的微型孔，这是由于频繁的刀具失效。微细电火花加工（micro-EDM）是钛合金微细孔加工的一种有效方法，但存在着排屑不当、电弧、短路、工具电极与工件频繁粘连、加工速度慢等问题。为了克服所有这些问题，作者开发了一种新的超声辅助微细电火花加工装置，并安装到现有的ZNC-EDM机床。通过实验研究了间隙电流（IG）、脉冲导通时间（Ton）、脉冲关断时间（Toff）和超声功率（UP）对超声辅助微细电火花加工钛合金工件的材料去除率（MRR）、刀具磨损率（TWR）和孔锥度（Ta）的影响。实验结果表明，在微细电火花加工中引入超声振动，对微细电火花加工的加工效率、加工宽度和加工温度有显著影响。对超声振动和非超声振动下HS-MEDM加工的再铸层和微孔圆度进行了对比观察。
Making miniature holes of acceptable tolerances in titanium alloys by conventional drilling is difficult due to frequent tool failure because of its poor thermal conductivity, high hardness, and high chemical affinity with cutting tool materials. Micro-electrical discharge machining (micro-EDM) has been found as a suitable method of machining of miniature holes in titanium alloys but it faces some problems such as improper flushing of the debris, arcing, short-circuiting, frequent adhesion of tool electrode with workpiece, and poor machining rate. To overcome all these problems, authors have developed a new ultrasonic-assisted micro-EDM setup and fitted to already available ZNC-EDM machine. The objective of the present work is to study experimentally the effect of gap current (Ig), pulse on-time (Ton), pulse off-time (Toff), and ultrasonic power (UP) on material removal rate (MRR), tool wear rate (TWR), and hole taper (Ta) due to ultrasonic-assisted hole sinking micro-EDM (UA-HS-MEDM) in titanium alloy workpiece. Experimental results reveal that introduction of ultrasonic vibration in hole sinking micro-EDM (HS-MEDM) has significant effect on MRR, TWR, andTa. A comparative observation regarding recast layer and circularity of microholes made by HS-MEDM with and without ultrasonic vibration has also been reported.