Analysis of oxidation behavior of laser cladding SiC-Ti based composite strengthening coating.

In this paper, the oxidation behavior and high-temperature tribological properties of laser cladding Ti-Al-Si-SiCx system coatings at 800°C in the air were studied. The results demonstrated that these coatings had Ti 5 Si 3 /Ti 3 Al eutectic structure before oxidation. The results of oxidation resistance suggested that the oxidation weight gain conformed to the parabolic law. An appropriate increase in SiC content is beneficial to lower the oxidation rate. The Ti 5 Si 3 phase has excellent oxidation resistance. TiC phase forms CO 2 product during the oxidation process. In addition, the diffusion rates of Ti and Al elements in the oxide layer are different. The combined effect of the two eventually leads to the gradual formation of pores in the oxide layer. The TiC-reinforced phase improves the friction coefficient of high-temperature friction, but its introduction significantly improves the high-temperature wear resistance. Additionally, the adhesion of the oxide film in the high-temperature wear process exerted a great influence on the wear mechanism. Ti-Al-Si-SiC 3 exhibited the lowest wear rate of 6.73 × 10−7 mm3 N−1 m−1. The wear mechanism is primarily adhesive wear, abrasive wear, and oxidative wear. • Ti-Al-Si-SiC 3 coatings are mainly composed of Ti 3 Al, Ti 5 Si 3 , and TiC phases. • The improvement of oxidation resistance of Ti-Al-Si-SiCx coating is the result of the interaction of Al and Si. • An appropriate amount of Si can promote the formation of Al 2 O 3 oxidation products. • Compared with Ti-Al-Si,the Ti-Al-Si-SiC 3 coating has excellent oxidation resistance and wear resistance. [ABSTRACT FROM AUTHOR]