| 摘 要： | Nb–Mo–ZrB_2 composites(V(Nb)/V(Mo) = 1) with 15 vol% or 30 vol% of ZrB_2 were fabricated by hot-pressing sintering at 2000°C. The phases, microstructure, and mechanical properties were then investigated. The composites contain Nb-Mo solid solution(denoted as(Nb, Mo)ss hereafter), Zr B, Mo B, and Nb B phases. Compressive strength test results suggest that the strength of Nb–Mo–ZrB_2 composites increases with increasing ZrB_2 content; Nb–Mo–30 vol%ZrB_2 had the highest compressive strength(1905.1 MPa). The improvement in the compressive strength of the Nb–Mo–ZrB_2 composites is mainly attributed to the secondary phase strengthening of the stiffer Zr B phase, solid-solution strengthening of the(Nb, Mo)ss matrix as well as fine-grain strengthening. The fracture toughness decreases with increasing ZrB_2 content. Finally, the fracture modes of the Nb–Mo–ZrB_2 composites are also discussed in detail.
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