Performance and increase fatigue life for Ti workpiece produced by EDM process

Abstract Effect of discharge current (range from 5 to 13 A) in electrical discharge machining (EDM) on the machining characteristics of pure Ti is investigated. The electrode wear rates (EWR), material removal rates (MRR), surface roughness (SR), micro-hardness, fatigue life and recast layer are measured. Increasing discharge current, the EWR, MRR, SR and the recast layer thickness also increases. Fatigue life is positively correlated with the micro-hardness of EDMed workpiece. Control charts are used to ensure the EDM process is well regulated and stable. EDMed surface is modified by plasma etching, the surface defects are gradually removed. EDMed surface coated with a TiAlN film has better surface quality and a significantly greater fatigue life.