Study on Preparation and Machining Performance of SiC/Cu Composites

SiC/Cu composite materials were fabricated by powder metallurgy, and microstructure of composite was analyzed by means of metallographic microscope. The high speed steel tool and cemented carbide tool are used as cutters, and machining performance of SiC/Cu Composites were studied by cutting lathe and wire-electro discharge machine. The relationship between wire-electro discharge machining cutting speed and pulse interval were studied by wire-electro discharge machine. The results show that the composite cutting surface roughness increases with increasing of the content of SiC particles when the size of SiC is 40μm, while composite cutting surface roughness decreases with increasing of the content of SiC particles when the size of SiC is 20μm, the cemented carbide tolls have longer life than high-speed steel tools. The surface roughness of composite increases with the increasing of source voltage, but it decreases with increasing of pulse interval in the wire-electro discharge machining cutting conditions.

A Half-Bridge Isopulse Power Supply For WEDM

In Wire Electro Discharge Machine (WEDM), as the big randomicity of electro discharge, single discharge energy is various. In this paper a resistor-less and half-bridge power supply is investigated based on pulse width modulation(PWM), whose single discharge energy is equal , adopting discharge control strategy of breakdown waiting. And the experiment shows the cutting speed and surface roughness of this isopluse power supply is superior to that of traditional isofrequency power supply.