The development and prospect of fabrication of W based plasma facing component by atmospheric plasma spraying

The possibility and development of fabrication of W coating by atmospheric plasma spraying (APS) is summarized and reported. SEM was used to investigate the surface and cross-section morphology of fabricated coatings, while EDS and XRD were used to investigate the compositions and phase of these coatings. Through controlling the condition and parameters of the APS, the oxidation of the W coating can be reduced significantly. The W coatings with different initial particle sizes resulted in different microstructures. The finer the particle size of the spraying powders, the lower the porosity will be. The effects of different interlayers on bonding strength were studied. The W coating deposited directly onto the copper substrate presented the highest bonding strength compared with coatings with different interlayers, while the coating with a graded W/Cu interlayer shows the best thermal shock resistance. The feasibility of fabrication of thick W coating by APS was also investigated. Pure W coating with a thickness of 2–3 mm and porosity less than 2% can be fabricated by APS.