纤维初始构形对金属基复合材料微观组织的影响

INFLUENCE OF THE ORIGINAL STATE OF FIBERS ON THE MICRO-MORPHOLOGY OF METAL MATRIX COMPOSITE

研究了束簇纤维预制型中纤维束内原丝自然分布、框架涂层结构和颗粒混杂三种初始构形对液相浸渗效果及微观组织的作用实验发现：纤维自然排布时浸渗缺陷的存在是必然的，浸渗压力的提高只能减小而不能完全消除该缺陷；采用框架结构涂层首先填充预制型中细小尖角空隙后，可在较低的压力下实现完全浸渗；颗粒与纤维的混杂使纤维相互分离，消除了细小空隙而使纤维束内完整充填；与框架结构相比。

In this paper, three original states of fibers i.e. naturally arranged. fixed with network coating. hybridized with particles in the fiber-bunch preform were studied. It has been found experimentally that incomplete infiltration is existed when fibers arranged naturally. Infiltrating defacts can be reduced by raising the liquid-infiltrating pressure, but can't be eliminated completely. In the case of fiber fixed with network coating, the filling of fine corners in preform were achieved in advance and then the preform can be infiltrated rather completely at low pressure. Finally, by the hybrid with particles, the fiber bunch is separated and the dead corners are eliminated, so the infiltration of preform is perfect. Comparing with fiber fixed with network coating, in the hybrid preform the fibers appear fully separeted and well-distrubuted in the composite.