Oxidation of double-glow plasma chromising coating on TC4 titanium alloys

Double-glow plasma surface chromising was performed on TC4 (Ti–6Al–4V) alloys, and the isothermal oxidation behaviour of TC4 was investigated at 650, 750, and 850 °C. The surface treatment caused the formation of a Ti–Cr mutual diffusion layer beneath the alloy surface. The chromising coating consisted of Cr, Cr1.97Ti1.07, and CrTi4. During oxidation, Cr, Ti, and Al diffused outward to form multi-layer oxide films, which prevented the diffusion...