High room-temperature plastic and work-hardening effect of the NiAl-matrix composites reinforced by particulates

The microstructures, interfaces, compression properties and work-hardening effect of the NiAl-matrix composites reinforced by 5–20 wt.% ceramic particulates (Nb2C, NbC and NbB2) fabricated by combustion synthesis and hot pressing (CSHP) have been investigated. The ultimate compression strength and yield strength increase with the increasing content of the ceramic particulates, while the fracture strain and work-hardening capacity (Hc) decrease. The NiAl-matrix composite with 5 wt.% ceramic particulates has a high true ultimate strength of 1497 MPa, a fracture strain of 18.3%, and work-hardening capacity Hc = 1.29. The good interface bonding between ceramic particulate and matrix, the high density dislocation in the NiAl matrix, the seriously distorted lattices and the intense interactions between dislocations and other crystal defects contribute to its prominent mechanical properties.