Tailoring growth structure and oxidation performance of CrWN glass molding coating via Pt and Ir doping

Detailed electron microscopy investigations were performed to evaluate the effects of PtIr on the growth structure and oxidation resistance of the CrWN coating. The undoped CrWN coating showed an obviously coherent growth and a rough growth texture with a roughness value of 13.80 nm. The doped PtIr atoms induced a prominent structural modification on the CrWN coating and effectively inhibited the coherent growth, leading to a smoother texture and a reduced roughness value of 4.75 nm. The CrWN coating exhibited a loose texture that permitted the internal diffusion of oxygen and degraded its oxidation resistance and roughness, but these doped PtIr atoms had high chemical inertness, which enabled them to act as oxygen diffusion barriers, consequently improving the oxidation resistance and coarsening resistance of the CrWN–PtIr coating.