Electrical discharge coating of ceramic metal composite on metal substrate using powder compact electrodes

摘要

EDM is a prominent non-traditional machining process, which is widely used for machining hard materials those are not possible by conventional processes. A very special aspect of this process is surface modification by material transfer from the tool electrode to the work-piece which is commonly known as an electro discharge coating (EDC). In this work, electrode prepared with tungsten (W)-copper (Cu) and with titanium carbide (TiC)-copper (Cu) powder by powder metallurgy (PM) route used as tool material and pure aluminum and AISI 1020 mild steel are used as work-piece. Using reverse polarity (tool as anode and work-piece as cathode) in electro discharge machine hard composite layer of WC-Cu on Aluminium substrate and TiC-Cu on AISI 1020 mild steel substrate have been deposited. The effect of compaction pressure during tool preparation by PM method and peak current (Ip) and pulse on time (Ton) during the EDC process on Deposition Rate (DR), Tool Wear Rate (TWR), Micro Hardness has been studied. Surface roughness of the coated surface have also been measured. Microstructures of the deposited layers are studied by using the optical images, while the compounds present in the coating are analyzed by XRD (X-Ray Diffraction) technique.