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Abstract: The microstructure, compression property and work-hardening effect of the NiAl-matrix composite with 1.7wt.% NbB2 and Nb x C (x =1 or 2) fabricated by the combustion synthesis and hot pressing technique have been investigated in the study. The NiAl-matrix composite has strong strain rate sensitivity. The yield strength of the NbB2–Nb x C/NiAl composite decreases while the fracture strain and the work-hardening capacity (H c) increase with decreasing strain rate. A high true ultimate strength of 1472MPa, a fracture strain of 20.1% and H c =1.41 were obtained under the strain rate of 2.0×10−5 s−1. [Copyright &y& Elsevier]

Abstract: Creep behavior of the unmodified and modified cast Al–Cu alloys was investigated at temperatures from 393 to 483K in the tension test. The creep resistance ability of the Al–Cu alloy modified by Pr x O y is almost 3–5 times as high as that of the unmodified Al–Cu alloy, which is attributed to a large number of nano-scale θ′ precipitates with high thermal stability in the modified Al–Cu alloy restricting and impeding the dislocation movement during the creep. The induction of a threshold stress in the analysis leads to a stress exponent of 5, which suggests that the creep behavior of both the present alloys is associated with the lattice diffusion-controlled dislocation climb (n =5). [Copyright &y& Elsevier]