Corrosion and abrasive wear behaviour of laser consolidated plasma sprayedSiC coating on Fe-15Cr-25Ni alloy

Silicon carbide powders (75 mu m) were plasma sprayed on austenitic Fr-15Cr -25Ni alloy. A continuous wave CO, laser was used to consolidate the plasma sprayed layer and to decompose SIC particles during glazing. Optical and s canning electron microscopic techniques revealed that the structure of the laser consolidated layer consisted of cellular dendrites with M7C3 carbides dispersed mainly, at the dendritic boundaries. Consequently. the surface h ardness of the Fe-15Cr-25Ni alloy improved considerably. Abrasive wear test s showed that the laser modified specimen exhibited lower wear mass loss an d a lower coefficient of friction than the raw Fr-15Cr-25Ni alloy. Potentio dynamic and cyclic polarisation behaviour of the laser modified and raw Fe- 15Cr-25Ni alloy specimens in 0.5M H2SO4 and 0.5M NaCl solutions was also in vestigated.