Microstructure and electrochemical properties of molybdenum base amorphous and nanocrystalline alloy coatings by plasma spraying

A coating was prepared on 0Cr13Ni5Mo stainless steel by air plasma spraying with a kind of molybdenum base alloy powder which contains Si, B, Cr, W, Mo, Ni etc. as the plasma spraying powder. It was proved that the Mo-base alloy coating fabricated by air plasma spraying has homogenous microstructure and contains metal glass and nanocrystals by X-ray diffractometer, SEM, TEM and Potentionstat/Galvanostat Model 273. The coating has high hardness and the highest micro-hardness can reach 1 426.9 HV. The porosity is about to 3.1%. Experimental results also show that Mo-base amorphous and nanocrystalline alloy coatings can appear a passivation phenomenon in a 3.5% NaCl solution with I_corr(R)=6.459μA·cm^-2 and E (I=0)=0.869 mm·a^-1.