摘要:
Nb–Mo–ZrB
2 composites (
V(Nb)/
V(Mo)=1) with 15vol% or 30vol% of ZrB
2 were fabricated by hot-pressing sintering at 2000℃. The phases, microstructure, and mechanical properties were then investigated. The composites contain Nb-Mo solid solution (denoted as (Nb, Mo)ss hereafter), ZrB, MoB, and NbB phases. Compressive strength test results suggest that the strength of Nb–Mo–ZrB
2 composites increases with increasing ZrB
2 content; Nb–Mo–30vol%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 ZrB 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.