Effect of temperature on the performance of sherardizing coating

To investigate the effect of the sherardizing temperature on the coating performance, several experiments were made at 380°C, 390°C, 400°C, 410°C and 420°C for 4h. The coating composition, morphology, thickness, mass, and microhardness were analyzed. The results show that the coating is continuous, dense and uniform. The coating is mainly formed by the diffusion of Zn and Fe atoms, and has a two-phase structure. The top layer is a thick FeZn10 phase, and the subjacent layer is a thin Fe11Zn40 phase. With the increase of temperature, the morphology and microhardness of coating change little, but the coating thickness and mass increase gradually.