Tungsten coating prepared on molybdenum substrate by electrodeposition from molten salt in air atmosphere

Compact and smooth tungsten coating on molybdenum substrate was obtained by electrodeposition from Na2WO4-WO3 molten salt at 1173 K in atmosphere. Microstructure, morphology and properties were performed on the tungsten coating. The tungsten coating had columnar structure with the preferential growth orientation of (2 0 0). There was about 2 μm thick diffusion layer of tungsten in the molybdenum substrate. The bending test and thermal shock test showed the tungsten coating had good adhesion with the molybdenum substrate. The microhardness of the coating was about 492 HV and the oxygen content of the coating was 0.032 wt%. The high-temperature could enhance the high-temperature oxidation resistance and bond strength of the tungsten coating.