Abstract:A porous Ni-based coating was fabricated by plasma spraying and subsequent remelt method. The microstructure, thermal expansion coefficient and mechanical properties during compress process were analyzed by scanning electron microscope (SEM), micro-hardness tester, thermophysical properties instruments and so on. The results show that the closed and spherical pore with 30-100 μm diameter formed in the remelt coating. The elasticity moudulus of the porous coating descend 69.5% and elasticity deforming scope ascend 68.7% with the porocity ascend to 30.6% from 0.53%. The average linear thermal expansion coefficient increased with the decreasing of porosity in the temperature scope between 40 and 220 ℃. The improvment of elasticity deforming scope of Ni-based alloy due to the formation of closed pore resulted in the decline of thermal expansion coefficient, to achieve the purpose of low thermal expansion and high recoverability.