Abstract: Microstructure and properties of the surface layer of a laser – remelted – treated as – cast Zn – 27% Al alloy are changed. The layer can be divided into non-dendrite, dendritel and partly – melted zones according to the features of the microstructure. Diffraction intensity ofη-Zn phase decreased and fringe effect appeared in the diffraction peakes ofα-Al phase on X – ray spectrometer after the alloy is treated, and hardness of the layer surface and wear resistance are increased respectly by 15% and 26% because of a very fine microstructure of the layer comparing with ones of the original alloy. The depth of the hardened layer increases with the increment of laser heating power.

Key words: Laser remelted processing, Zn – 27% Al alloy