Reactive molecular dynamics simulation study of wear mechanism of SiO2 and TiO2 passive films on MoSiBTiC alloy in high-temperature humid environment

Abstract Amorphous SiO2(a-SiO2)/rutile TiO2 composite films on MoSiBTiC alloy exhibit high wear resistance. However, high-temperature humid environments can accelerate wear. This study examines the wear mechanisms of rutile TiO2(110) and a-SiO2 passive films in a high-temperature humid environment by using molecular dynamics simulation. TiO2 was worn significantly by mechanical deformation and chemical reactions with water, although TiO2 has higher Vickers hardness and chemical stability than SiO2. The remarkable wear of TiO2 is attributed to the exceptionally low shear strength of the rutile TiO2(110) surface.