Experiment study of dispersion uniformity of short carbon fiber reinforced silicon carbide

As carbon fiber reinforced silicon carbide composites combine the excellent mechanical properties of carbon fiber with good oxidation resistance of silicon carbide, considering material properties and economic cost, so much attention has been focused on short fiber reinforced ceramic matrix, but short carbon fiber is difficult to uniformly dispersed in the silicon carbide matrix, so how to disperse short carbon fibers in the matrix has become the key to prepare composite materials. In this article, through three processing methods to improve the dispersion, the three method are surface treatment of short carbon fibers, changing the mixed material ball milling time and adding a certain amount of SiC whisker. Results showed that the three processing methods all can improve the dispersion of short carbon fibers in silicon carbide matrix, but the dispersion effect also are different and the mechanism are different.the composites with better dispersion can achieved when carbon fibers which oxidized in concentrated nitric acid (68%) for 90minutes,and ball milling time was 48h and the concentration of SiC whisker was 5%.