Abstract: Remelting treatment of FeNiCrAl coating deposited by high-velocity arc spraying was conducted using laser technology. The microstructure， phase composition， microhardness and fracture toughness of the coating before and after remelting were analyzed. The results showed that the layer stack structure and pores of the spraying coating were eliminated， the microstructure of the coating became uniform and dense， and the interaction between the coating and the substrate were changed from mechanical combination to metallurgical bonding after remelting. Compared with the phases of the spraying coating， which consisted of α-Fe and intermetallic compounds， such as AlFe₃， AlFe and Al_0.4Fe_0.6， three more phases could be observed after remelting， which were a new phase of Fe-Cr， the solid solution of ［Fe， Ni］ and carbide NiC_○x. The average microhardness of the coating after remelting was 7.79GPa， which was about 3 times than that of the substrate (2.5GPa) and about 1.3 times than that of the spraying coating (6.0GPa). In the indentation test of the spraying coating， the indentation cracks appeared at the loads of 4.9 and 9.8N， corresponding to the average fracture toughness of spraying coating of 1.20MPa·m^1/2， while no crack was found during loading of 2.94~9.8N after remelting.

Key words: laser remelting, high-velocity arc spraying, FeNiCrAl coating, microstructure, fracture toughness