High Temperature Oxidation Behaviors of BaO/TiO₂ Binary Oxide-Enhanced NiAl-Based Composites

High temperature lubricating composites have been widely used in aerospace and other high-tech industries. In the actual application process, high temperature oxidation resistance is a very importance parameter. In this paper, BaO/TiO₂-enhanced NiAl-based composites were prepared by vacuum hot-press sintering. The oxidation resistance performance of the composites at 800 °C was investigated. The composites exhibited very good sintered compactness and only a few pores were present. Meanwhile, the composite had excellent oxidation resistance properties due to the formation of a dense Al₂O₃ layer which could prevent further oxidation of the internal substrate; its oxidation mechanism was mainly decided by the outward diffusion of Al and the inward diffusion of O. The addition of BaO/TiO₂ introduced more boundaries and made the K_p value increase from 1.2 × 10^-14 g²/cm⁴ s to 3.3 × 10^-14 g²/cm⁴ s, leading to a slight reduction in the oxidation resistance performance of the composites-although it was still excellent.