The Parametric Analysis in Fabrication of Tungsten Carbide Alloy Rod by Electrochemical Machining

• Main Authors: Qing-huang Zhao, 趙清煌
• Other Authors: Lih-wu Hourng
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/33298594800715427170

碩士 === 國立中央大學 === 機械工程學系 === 104 === 　　Electrochemical machining (ECM) is one of the non-traditional manufacturing process, shaping workpiece by electrolysis. The advantages are that the process is independent of material properties, little or no tool wearing, no surface stress, and good surface finishing. The machining equipment is relatively simple and inexpensive with fast processing speed, and capable of complex workpiece geometry. 　　Tungsten carbide (WC) alloy has high stiffness and high surface hardness, commonly used in cutting tools and mold. But in ECM, passivation layer will be generated in sodium nitrate (NaNO3) electrolyte, and significantly reduce the material removal rate (MRR) in anode. The object of this study was to take sodium nitrate and ammonia hydroxide (NH4OH) as hybrid electrolyte in ECM process, and investigate the effects of various processing parameters (e.g. applied voltage, NaNO3 concentration, NH4OH concentration, electrode rotation speed, and machining time) on MRR and electrode shape. 　　The results show that, with condition of 20 V, 4 M NH4OH and 3000 rpm, there will be largest MRR. Meanwhile, the shape of electrode will be tapered if NaNO3 is 2 M, and reversely tapered with uneven surface if NaNO3 is 4 M. Surface quality will slightly degrade after machining. Machining time can control MRR rather than electrode shape.