Abstract: The flexural strength of 30% (volume fraction) ZrC particlereinforced tungsten composite (ZrC_p/W) at 20～1200℃ were measured using three-point bending, and the fracture behaviors of the samples at 20℃ and 1000℃ were studied with a scanning electron microscope. As temperature increases, the strength of the composite increases firstly and the highest strength value, 829MPa, is measured at 1000℃,and then the strength decreases when temperature is over 1000℃.The fracture of the composite at 20℃,which is controlled by the crack initiating process, is brittle, and the corresponding stressdeflection curve is linear. There is a metastable growth and coalescence of the initial cracks during the fracture process of the samples at 1000℃,and the stressdeflection curve displays a nonlinear characteristic. The good elevated strength of the composite is partly attributed to the W grain interior strength and ZrC_p/W interface strength. The reinforcement at high temperature is mainly attributed to the load transfer of ZrC_p/W interface and dislocation strengthening.

Key words:  tungsten composite; zirconium carbide; strength; fracture behavior