Parametric effect on electrical discharge treatment of magnesium alloy with powder composite electrode

In this present investigation, an attempt has been made to deposit the composite coating on ZE41A magnesium alloy using tungsten carbide and Nickel powder metallurgy electrode by electro discharge deposition. The experiment is conducted using ordinary EDM and EDM oil as dielectric fluid. Compaction load, current and pulse on time are selected as the input parameters that influences the characteristics such as deposition rate (DR) and electrode wear rate (EWR). Micro hardness of the deposited is evaluated using vicker hardness tester. Mathematical models are developed to study the effect of process parameters on the responses. It is revealed that the DR and EWR increases with increase in current and pulse on time at low compaction load, but it decreases at high compaction load. Maximum DR and EWR are achieved at compaction load (150 MPa), current (4 A) and pulse on time (90 µs). Maximum hardness values (772 HV) is achieved at surface deposited with low compaction and high current and pulse on time. Scanning electron microscope and Energy dispersive spectroscope are carried out in the deposited workpiece to study microstructural and confirm the presence of electrode materials respectively.