Abstract
The compact ram-type electric discharge machine for fabricating small holes was experimentally developed. Electric discharge machining properties of titanium (Ti), Co-Cr-Mo alloy (Co), Ag-Pd-Cu-Au alloy (Pd), and Ag-Sn alloy (Ag)were evaluated on this machine. Cast specimens with a thickness of 3, 5, and 10 mm were prepared. Hollow cylinder copper bars with a diameter of 0.7, 1.2, and 1.6 mm were used as an electrode. The effect of the rotation of electrode was examined. Higher machining speed was obtained in the specimens of Ag, Pd, Co, and Ti in decreasing order. On the contrary, higher electrode elimination ratio was obtained of the specimens of Ti, Co, Pd and Ag in decreasing order. Rotation of the electrode was useful to increase machining speed and to decrease electrode elimination ratio and clearance. Small holes ware prepared using electric discharge machining with a developed machine to apply to dental laboratory works.
