A protective SiAlN coating on topographic surface of laser powder bed fusion manufactured Ti alloy

Protective SiAlN coating with Mo interlayer has been directly deposited onto as-built topographic surface of laser-based powder bed fusion manufactured Ti6Al4V alloy where high surface roughness, even with irregular geometrical features and native oxide scale on it. The topographic surface of Ti6Al4V is well protected by SiAlN/Mo coatings without spallation, cracks or even oxidation after 50 h of exposure at 800 °C for 10 cycles in air. The conformal nature of sputtered SiAlN/Mo coatings enables topographic surface to be well covered, and Mo diffuses through thin native oxide scale on topographic surface into Ti alloy, thereby forming strong chemical bonding between coatings and Ti substrates.