Abstract:Tungsten (W) coating plasma facing material (PFM) was fabricated on the copper (Cu) substrate by means of plasma spraying technolgoy, and it was analysed that the coating porosity, the theoretical density, the bonding strength between tungsten coating and copper substract, the thermal conductivity, the Vickers micro-hardness distribution of tungsten coating. And it was discussed in detail that the damage evolution of tungsten coatings with both of the direct and in-direct cooling condition. The results indicated that the failure reason of W PFM with the direct cooling was the delamination between the lamellar layers, not the surface damage. The damage evolution of W PFM was as follows: the columnar crystals growing up, micro-cracks between the lamellar layers, then the lamellar layer delamination and W PFM failure. But under the indirect cooling, the heat flux performance of W PFM was limited to 7.5MW/m2, not the 10MW/m2 of the direct cooling W coating, and the main failure behaviors were W coating detachment from Cu substrate, which was induced by Cu melting.