Study On Processing Performance Of Powder-Mixed EDM

The technology of Powder-mixed EDM that can overcome the defaults of conventional EDM improve the surface quality,decrease surface roughness,and realize the surface finishing of large area. has a wide application in die&mould. It observed the micro structure of the Powder-mixed EDM workpiece and analyzed the features. Then it optimize the Discharge Parameter and generated the large area workpiece which can meet the requirements. It includes:To study the micro structure ,a series of comparative experiments were carried on. Based on the experiments results, it explained the existence of the surface defects, analyzed the influences of Discharge Parameter to White re-cast Layer and Crater, optimized the Discharge Parameter of Powder-Mixed EDM, generated the large area workpiece. It was shown that: The micro cracks are mainly existence in the formation of white re-cast layer. When the Peak Current reduced, the thickness of the white re-cast layer lowered, the diameter of the Crater got smaller. But the thickness of the white re-cast layer would be increase when the Peak Current became much more smaller. The reduce of the Pulse Width can lower the thickness of the white re-cast layer, make the uniformity better. When Pulse Width decreased, the diameter of the Crater would be smaller. The reduction of the Servo-Volt would decrease the defects, generate the Craters with larger diameter.Meanwhile, it analyzed the surface roughness influencing factors in PMEDM including electrical Parameter,such as Peak current,Pulse duration and non-electrical factors,such as added powder, electrode, workpiece material, temperature, the frequency of cutting UP and DOWN,jet flushing. It optimized the Discharge Parameter and generated the large area workpiece, which area is 10000mm2 and Ra is 0.39~0.42μm. It verified the availability of the results.