Synthesis and mechanical properties of niobium aluminide-based composites

摘要

Niobium aluminide-based composites reinforced with in situ and externally added Al_2O_3 and TiC particulates were fabricated by hot-pressed sintering at 1400 ℃. In particular, Nb_2Al-Al_2O_3-TiC in situ composites were successfully obtained from the raw powder mixtures of Nb60A140 (in at.%)-TiO_220C8 (in wt.%) by means of this process. The influences of ceramic particulates on the microstructures, flexural strength and fracture toughness were examined. The experimental results indicate that the presence of ceramic particulates yielded a remarkable improvement in both the strength and fracture toughness in comparison with previous results for monolithic niobium aluminide compounds.