Effect of TiC Particles on High-Temperature Properties of Al-Li Alloy and Coarsening of Al₂CuLi(T₁) Precipitates

This study investigates the effect of TiC particles regarding the properties of aluminium-lithium alloys under high-temperature conditions, focusing on the reinforcing effect of TiC and TiB₂ particles in the aluminium matrix and the effect on the coarsening process of T₁ precipitates. Aluminium-lithium alloys are widely used in aerospace applications, especially as skin materials for fast vehicles, due to their excellent high specific strength and corrosion resistance. However, conventional aluminium alloys are inadequate in meeting the elevated temperature service requirements associated with supersonic flight. Consequently, there is a significant scientific imperative to investigate the heat resistance of novel aluminium-lithium alloys. The inclusion of TiC and TiB₂ nanoparticles has been demonstrated to enhance the mechanical properties of the alloys, particularly at high temperatures of 200 °C. These particles have been shown to enhance the strength and toughness of the alloy through mechanisms such as grain refinement and increased dislocation density. Concurrently, this study determined that the coarsening phenomenon of T₁ precipitates occurs at elevated temperatures. The inclusion of TiC particles, however, has been shown to inhibit the coarsening process, delay the coarsening of the T₁ phase, and enhance the mechanical properties of the material. This outcome is of considerable significance for the composition design of aluminium-lithium alloys and their performance optimisation in high-temperature applications.