Effects of Treatment Parameters on Microstructure of Diffusion Alloyed Coatings on Pure Magnesium

Abstract

In the present study, the effect of various solid state diffusion times (8 h, 16 h, 24 h) on the microstructure of diffusion alloyed samples and its corresponding composition and microhardness changes were investigated at 480°C. Optical microscopy, SEM, EDX and microhardness techniques were used to examine the treated samples cross-sectional morphology, microstructure and the corresponding composition and microhardness changes. The results show that, with increasing time, the alloy layer zone changes from one subzone (the transition subzone) to two subzones (white phase subzone and the transition subzone). At a diffusion alloying time of 24 h, two distinct subzones were observed in the alloying layer, continuous white phases (WP zone) consisting of the Al₅Mg₁₁Zn₄ phase was present in the outermost layer of diffusion alloying zone, and the microhardness value for Al₅Mg₁₁Zn₄ phase (WP zone) was ≤332 HV, which is beneficial from the point of view of wear resistance. SE/507