Magnesium alloys are used in many applications, particularly in orthopaedic implants are very difficult to machine by conventional processes because of their complex 3D structure and limited slip system at room temperature. Hence there is an inherent need for alternative processes for machining such intricate profiles. Electric Discharge Machining is growing rapidly in tool rooms, die shops and even in general shop floors of modern industries to facilitate complex machining for difficult-to-machine materials and provide better surface integrity. Therefore, the use of electric discharge machining on ZM21 magnesium alloy is attempted in this paper. Nanographite powder is added for machining zone to enhance the electrical conductivity of EDM oil by way it improves the machining performance. Machining parameters such as the current, pulse on time and pulse off time were process parameters to explore their effects on the material removal rate and tool wear rate. It is observed that, an increased material removal rate was due to the enhanced electrical and thermal conductivity of the EDM oil.
Continuous observation of twinning and dynamic recrystallization in ZM21 magnesium alloy tubes during locally heated dieless drawing
