Manipulating Interface Bonding and Microstructure Via Tuning Interfacial Reaction for Enhancing Mechanical Property of In-Situ TiC/Al Cermets

A strong interface and microstructure design is the key to the development of the ceramics/Al composites with high strength-ductility synergy. This work aims to manipulate the interface bonding and microstructure via tuning interfacial reactions. The 70 vol% TiC/Al cermets with different Ti/C molar ratios were produced by the reaction hot pressing and the manipulation mechanism of interface bonding and microstructure were elaborated. When the Ti/C = 1.1, excessive Ti promotes the formation of Al3Ti in the cermets, where the trace Al3Ti with the size of 40.3 nm is presented at the interface between TiC and Al, thereby forming a strong TiC/Al3Ti/Al interface owing to the excellent crystallographic match and wettability between Al3Ti with α-Al or TiC. Further, the TiC/Al cermet with Ti/C = 1.1 demonstrates stronger mechanical properties, i.e. 33% and 189%, 3% and 8%, 35%, and 511%, respectively, higher ultimate compressive strength and plastic strain than those with Ti/C ratio of 0.8, 1.0 and 1.3. Meanwhile, the cermet demonstrates a higher strength-plasticity synergy compared to the reported carbide/Al composites. The enhanced mechanical properties are attributed to the synergistic strengthening effect of the multi-phase and micro/nano multi-scale of TiC and Al3Ti, the strong interface bonding, reasonable morphology of particles, and high compactness in the cermet caused by trace interfacial reaction product Al3Ti. This would open a new perspective for manipulating interface bonding and microstructure by tuning interfacial reaction products to improve the mechanical properties of cermets.