Study of Thick Tungsten Coatings Deposited on Various Molybdenum and Copper Substrates

Thick pure tungsten coatings were deposited on molybdenum and copper substrate by vacuum plasma spray for different purpose. The microstructures of tungsten coatings were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of preheating temperature of the substrate and introduction of gradient bond layer on the adhesive strength of the coating was investigated. High heat load was tested by high power electron beam bombardment only for tungsten coating on copper. All the results show that the properties of tungsten coating were strongly influenced by different processes, and the density of the coatings is close to 95% of theory density.