Fabrication and Properties of SiC Whisker Reinforced NbC Composites

Abstract

SiC whisker-reinforced NbC composites were fabricated by the hot-pressing method. NbC, SiC whisker (V_f=10-30%) and 1wt% Cr₇C₃ were mixed with a ball mill, then hot-pressed at 1600°C, 330kg/cm² for 1h in Ar atmosphere. Flexural strength (σ_f), fracture toughness (K_IC) and Vickers hardness (H_v) were measured at room temperature. All of these mechanical properties were improved by whisker reinforcement. For the composite having V_f=30%, σ_f, K_IC and H_v were 880MPa, 5.74MPa√m and 24.7GPa, respectively. Crack deflection and grain growth inhibition of the matrix were observed as a result of whisker incorporation.