Enhanced ductility of Ti₃AlC₂ particles reinforced pure aluminum composites by interface control

In this paper, TiAl₃ whiskers were in-situ formed at the interface of Ti₃AlC₂ particles reinforced pure aluminum composites through spark plasma sintering. The phase composition, microstructure, and mechanical properties of 20Ti₃AlC₂/80Al composites were investigated. It was confirmed that the size and content of TiAl₃ whiskers could be adjusted by changing the preparation temperature. The XRD and TEM analyses indicate that the TiAl₃ whiskers could be formed when the sintering temperature is 620 °C and above. The results also show that the formation of the TiAl₃ phase at the interface could effectively improve the mechanical properties of the as-sintered composites, which is attributed to the enhanced effect of TiAl₃ on interface bonding and load bearing. When fabricated at 620 °C, the average diameter of TiAl₃ whiskers is 79 nm, and the elongation of the composite is up to 17.5%. In addition, obvious bending deformation of Ti₃AlC₂ particles was observed through the fracture morphology, indicating that the stress of the matrix was effectively transferred to the reinforcement. It is determined that in the Ti₃AlC₂/Al system, the stress of the matrix can be effectively transferred to the MAX phase through the interface control, and the strength and ductility of composites can be improved simultaneously through the coordinated deformation of the Ti₃AlC₂ particles.