Strength properties and fracture behavior of ZrC particle-reinforced tungsten composite

À´Ô´ÆÚ¿¯£ºÖйúÓÐÉ«½ðÊôѧ±¨(Ó¢ÎÄ°æ)2001ÄêµÚ6ÆÚ

ÂÛÎÄ×÷ÕߣºÍõÓñ½ð ËιðÃ÷ ÃÏÇì²ý ÖÜÓñ

ÎÄÕÂÒ³Â룺868 - 872

Key words£ºtungsten composite; zirconium carbide; strength; fracture behavior

Abstract: The flexural strength of 30% (volume fraction) ZrC particleª²reinforced tungsten composite (ZrC_p/W) at 20ªª¡«1200¡æ were measured using three-point bending, and the fracture behaviors of the samples at 20¡æ and 1000¡æªª were studied with a scanning electron microscope. As temperature increases, the strength of the composite increases firstly and the highest strength value, 829MPa,ªª is measured at 1000¡æ,ªªand then the strength decreases when temperature is over ª©1000¡æ.ªªThe fracture of the composite at 20¡æ,ªªwhich is controlled by the crack initiating process, is brittle, and the corresponding stressª²deflection curve is linear. There is a metastable growth and coalescence of the initial cracks during the fracture process of the samples at 1000¡æ,ªªand the stressª²deflection 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.