Microstructure and room/high-temperature tensile properties of γ-TiAlNb intermetallic compound subjected to heat treatment

Abstract

This study aims to investigate the influence of high-temperature heat treatment on the microstructure and mechanical properties of titanium aluminide niobium (γ-TiAlNb) intermetallic compounds. Systematic experiments revealed that heat treatment at 1280 °C resulted in significant changes in various aspects. Firstly, there was a notable reduction in grain size. Secondly, the content of α2-Ti3Al phase increased significantly, leading to a more complex phase distribution. Thirdly, heat treatment induced the formation of a strip structure of β-Ti phase within the grains, providing unique advantages for the material's thermal stability and mechanical performance. Then, the detailed mechanical performance tests indicated a significant improvement in the material properties of TiAlNb intermetallic compounds at both room and high temperatures following heat treatment. The ultimate tensile strength increased significantly, while the elongation also showed a substantial improvement. Finally, these results were closely associated with the evolution of the microstructure, revealing the precise control mechanism of heat treatment on material performance. Further analysis of elemental distribution demonstrated that heat treatment had a minor impact on the elemental content of TiAlNb intermetallic compounds. In conclusion, this study provides profound insights into the mechanisms underlying the improvement of TiAlNb intermetallic compound properties through heat treatment. The findings offer valuable guidance for the engineering optimization and application of such materials in the future.