Fabrication of thick W coatings by atmospheric plasma spraying and their transient high heat loading performance

Both tungsten coatings with or without a W/Cu graded interlayer on an oxygen-free copper substrate were fabricated by atmospheric plasma spraying. High purity argon gas was used for cooling the substrate and preventing the coating from oxidation. The thickness of both coatings is ∼1mm. XRD and EDS measurements of the coatings show that minimal oxidation occurred during the deposition process. Transient high heat load tests by electron beam with a pulse duration of 5ms were performed on both coatings. The single pulse loading was applied on the virgin surfaces at several power densities (from 0.22 to 0.9GW/m2). Although the weight loss of the W/Cu FGM (functionally graded materials) based coating was slightly lower than that of the pure W coating, their transient high heat loading performances were quite similar.