SiC_f/Ti-6Al-4V复合材料的断裂韧性(英文)

Fracture toughness of SiC_f/Ti-6Al-4V composites

采用三点弯曲法测定了SiC纤维单向增强的Ti-6Al-4V复合材料的表观断裂韧性,讨论了界面反应对断裂韧性的影响。研究结果表明,在裂纹尖端塑性变形区的未断纤维的桥联对复合材料的断裂韧性起很大的作用。经过热处理后,SiCf/Ti-6Al-4V复合材料的断裂韧性降低,主要是由于严重的界面反应,使得SiC纤维受到一定的损伤,因而降低了纤维的承载能力,并使基体钛合金的脆性增大。

Apparent fracture toughness of the Ti-6Al-4V alloy uniaxially reinforced with SiC fibers was measured by three-point bending test and the effect of the interfacial reaction on toughness was discussed.It is pointed out that bridging of the intact fibers in plastic zone ahead of the crack tip plays an important role for fracture toughness of the composites.And fracture toughness of the heat-treated composites decreases due to the severe interfacial reaction that leads to damage of the SiC fibers and therefore the decrease of the load-bearing ability,and to the increase of the brittleness in the titanium matrix.