The effect of material grain structure on the surface integrity of components processed by microwire electrical discharge machining (μWEDM)

The machining response of metallurgically and mechanically modified materials
when processed by employing the microwire electrical discharge machining (µWEDM) technology is reported in this paper. In particular, the effects of the material microstructure on resulting surface integrity of Al5000 series aluminium alloys after µWEDM processing is studied. The machining response of an ‘as received’ aluminium alloy was compared against the results obtained on samples processed through extrusion strain hardening and severe plastic deformation. Especially, the process–material effects on the resulting microhardness, phase content changes, heat-affected zone, surface roughness, microcracks, recast layer, material removal rate, and element spectrum after both rough and finishing µWEDM cuts were investigated. This study shows that an ultrafine grained (UFG) Al5083 exhibits not only superior mechanical properties but also the machining response to µWEDM is favourable. A reduction of the recast layer after WEDM was observed when compared with ‘as received’ and ‘conventionally’ processed Al5083.