利用等离子体喷涂技术制备了钨涂层面对等离子体材料,并对涂层基本性能进行了表征,主要包括气孔率、相对密度、结合强度、热导率、硬度分布,进而研究主动水冷钨涂层在热负荷服役条件下的损伤演变行为。研究发现,直接水冷钨涂层内部层与层之间的开裂、分层是涂层失效的原因,损伤演变过程为柱状晶体再结晶并长大、层间微裂纹出现、裂纹扩展和气孔出现、最后材料分层、失效。间接水冷钨材料的热负荷性能受到很大限制,且疲劳性能降低,失效形式是涂层开裂或脱落,甚至铜基体整体熔化。
Tungsten(W) coating plasma facing material(PFM) was fabricated on the copper(Cu) substrate by a plasma spraying technique,and the properties of the coating were characterized,including the coating porosity,the theoretical density,the bonding strength between tungsten coating and copper substrate,the thermal conductivity,and the Vickers micro-hardness distribution.And the damage evolution of the tungsten coatings with both of the direct and in-direct cooling condition was also investigated.The results indicate that the failure of W PFM with the direct cooling is attributed to the delamination between the lamellar layers,not the surface damage.The damage evolution of W PFM is as follows:the columnar crystals grow up,micro-cracks appear between the lamellar layers,then the lamellar layer delaminates and finally W PFM fails.But under the indirect cooling,the heat flux performance of W PFM is limited to 7.5 MW/m^2,while that of the direct cooling W coating is 10 MW/m^2.The main failure behavior is W coating detachment from Cu substrate,which is induced by Cu melting.