Electrochemical Discharge Grinding of Metal Matrix Composites Using Shaped Abrasive Tools Formed by Sintered Bronze/diamond

Abstract

Electrochemical discharge machining (ECDM) is a well-known process for machining of particulate reinforced metal matrix composites (MMCs). However, ECDM process suffers several drawbacks such as the lower material removal rate (MRR), high risks of tool wear rate (TWR) and relatively poor surface quality, etc. This study proposes a kind of electrochemical discharge grinding machining (ECDGM) method which employs a special shaped tool electrode. During the process, not only the can the hybrid action of electrochemical dissolution, spark erosion, and abrasive grinding improve the performance of machining MMCs, but also the special shaped of the tool electrode can be used to discharge the machined debris. And thus a higher machining efficiency and lower TWR can be obtained. The performance of developed process was conducted on machining of SiC particulate reinforced aluminum workpiece. The role of peak curre+nt, pulse duration, duty cycle, rotary speed and abrasive grit size has been investigated on MMR and TWR using the nonabrasive round electrode, abrasive round electrode, and abrasive shaped electrode respectively. The experimental results showed that using the shaped abrasive electrode for machining MMCs can achieve a higher MRR and lower TWR, as compared to the non-abrasive round electrode, abrasive round electrode. Besides, the orthogonal method was employed to analyze the relative importance of the machining parameters on MRR and TWR, it has been observed that MRR is affected by the processing parameters following the order of rotary speed > peak current > duty cycle > pulse duration, and TWR is following the order of peak current > duty cycle > pulse duration > rotary speed.

Keywords

• ecdm
• mmcs
• mrr
• twr
• shaped abrasive tools
• orthogonal method