Impact of heat treatment on the surface quality of electropolished WE43 alloy

• Study of correlation of microstructure and electropolished magnesium alloy surface. • Electropolishing WE43 enables high surface quality for F, T4 and T6 microstructure. • The size and morphology of precipitates show greater influence than their quantity. • Coarse precipitates in cast WE43 produce surface defects in a similar size range. • No or fine precipitates lead to defect-reduced and smooth electropolished surfaces. In this study, the Mg alloy WE43 was solution annealed and precipitation hardened prior to electropolishing to evaluate the effects of different microstructures on the electropolishing result. While coarsely distributed precipitates led to surfaces showing wavy structures and dents after electropolishing, a uniform microstructure resulted in an even finish of the surface. The homogenization and refinement of the microstructure by heat treatment is a method to ensure improved electropolished surfaces of Mg materials.