Peculiarities of Phase Composition, Microstructure, and High-Temperature (600–700 °C) Fracture Toughness of Ti–Al–Cu Composite

Among advanced Ti-based composites, Ti–Cu–X alloys have an advantage in high-temperature electrical conductivity. Due to comparatively high electrical conductivity at elevated temperatures, their application area can include spring electrical contacts of power equipment and other products operating in similar conditions. Besides, copper in these alloys contributes to strong antibacterial properties while maintaining good mechanical properties and corrosion resistance. These properties allow the use of Ti–Cu–X alloys in medicine. This work is aimed at studying the phase composition, microstructure, and high-temperature (600–700 °C) fracture toughness of the Ti–Al–Cu composite. Ingots of the composite were prepared by melting in a vacuum induction furnace. The following phase fractions were determined using X-ray diffraction analysis of the composite: Ti2Cu (58.3 wt%), TiCu (37.5 wt%), Ti3Cu (4.2 wt%). Bar specimens were prepared by electric-discharge cutting of ingots, and then the specimens were ground and polished. The specimens with a sharp edge notch underwent the fracture toughness test in a wide temperature range (20 °C to 700 °C). Based on the test results, it was concluded that the Ti–Al–Cu composite can be successfully used for manufacturing electrical contacts of power equipment.