High temperature oxidation resistance of metal silicide incorporated ZrB2 composite coatings prepared by vacuum plasma spray

摘要: Abstract Metal silicides are often utilized to enhance high temperature oxidation resistance for refractory ZrB2 ceramics or coatings owing the capability form glassy silica layer. However, role of metal elements in on maintaining layer needs be elucidated. In present study, TaSi2 and MoSi2 incorporated composite were respectively prepared by vacuum plasma spray (VPS) technology their behaviors comparatively investigated. The tests carried out ambient air at 1773 K confirmed crucial function both silicide coatings. More importantly, additives revealed have great influence integrity element Ta generated plate-like compound TaZr2.75O8, which impaired consistency completeness layer, creating opportunity oxygen diffusion. MoB, product Mo MoSi2, could help supporting MoB played defending wholeness reducing evaporation B2O3 MoO3 same time. Better ZrB2–MoSi2 coating was found as compared with ZrB2–TaSi2 coating.