Manufacture of thick VPS W coatings on relatively large CuZrCr substrate and its steady high heat load performance

Abstract W material is considered as one of potential Plasma Facing Materials (PFMs) for its high melting point, excellent stability at elevated temperature, good thermal conductivity, excellent anti-plasma sputtering and low Tritium retention. Functionally graded W/Cu coating was applied on CuCrZr substrate (250 mm × 120 mm × 30 mm) with compositionally gradient W/Cu as bond coat (0.4–0.6 mm) and 1.5 mm thick W coating as top coat via Vacuum Plasma Spraying (VPS) for continuous deposition of 5 h. Microstructure, chemical composition, porosity and adhesive strength for as sprayed thick W coating on the CuCrZr substrate were characterized by means of SEM, ICP-MS, Mercury Intrusion Porosimeter and tensile strength tester. The steady high heat load (HHL) performance for W/Cu functional gradient coating was evaluated by high energy electron beam. The results showed that thick VPS W coated CuCrZr substrate can withstand the steady high heat load at the electron beam power density of 9 MW/m 2 for 1000 cycles.