The machining characteristics of PCD by micro wire electrical discharge machining(μ-WEDM)

• Main Authors: Ssu-Yi Chen, 陳思懿
• Other Authors: Tzu-Yao Tai
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/99462075863296962446

碩士 === 南台科技大學 === 機械工程系 === 100 === Polycrystalline diamond (Polycrystalline Diamond, PCD) has high hardness, high strength, high wear resistance, high thermal conductivity, low coefficient of friction and many other outstanding features It is widely used to mold high-speed milling and can be used to process hard non-ferrous metal and cut nonmetal materials. The micro-wire electrical discharge machining is the most appropriate processing method, because the slight wire electrode cutting grooves, the same as Polycrystalline Diamond material can cut out the PCD knives or components and therefore reduce production costs.Wire electrodes used in the study is the 50μm micro copper wire, and the material is polycrystalline diamond (PCD) with the grain size of 2μm, 5μm.The results of Taguchi experiment indicated that the cutting width and material removal rate of the main processing parameters influence the servo gap voltage, wire tension, While the surface roughness of the main factors is affected by the open circuit voltage and the servo gap voltage. Servo gap voltage of 10 has the best dimensional accuracy and surface quality.Low-voltage discharges relatively less energy, so the cutting width and surface roughness are the best, and the servo gap voltage of 20 has the best of the material removal rate.When the set of wire tension is too high or low , the machining process becomes unstable,Which leads to an increase in processing time, and decrease in material removal rate,and results in an increase in surface roughness of the machined surface.The wire tension of 2N has the best material removal rate and surface roughness.The maximum wire tension of 3.8N wire electrode has a tension effect, and the processing width is the best. According to the analysis of the PCD wheel knife, grain size 2μm PCD is superior to grain size 5μm in terms of wheel knife burn layer, the cutting width, and surface roughness.Therefore, the grain size 2μm of crystalline diamond is more suitable than grain size 5μm as a machining wheel knife.