Fabrication of micro electrode of carbide and micro hole machining characteristics of Ti-6Al-4V alloy by electrical discharge machining

摘要

This paper deals with the fabrication ofmicro electrode of carbide and micro hole machiningcharacteristics of Ti-6Al-4V alloy. The experimentalresults show that the material removal rate of carbidemachined with small discharge energy in positivepolarity is larger than that in negative polarity. Andwhen machining carbide wit small discharge energy, theenergy supply mode, such as large current and shortpulse duration, is efficient for promoting the materialremoval rate. When machining micro hole of Ti-6Al-4Valloy in positive polarity, compared with negativepolarity, both the material removal rate and electrodewear rate are larger. It is also shown that the energysupply mode, such as small current and short pulseduration, can increase the material removal ratebecause of the formation of smaller debris result ineasy ejection of debris out of the small gap.Experimental result indicate that when machining microhole of Ti-6Al-4V alloy, the most significant effecton micro hole accuracy is the machining depth. Thereason is that micro deep hole machining will makedebris accumulating on the bottom of micro hole to leadto the occurrence of discharge concentration, and thenresult in the formation of ellipse hole.