1990 Volume 76 Issue 1 Pages 65-72
Recently, SiC fiber from polycarbosilane (SiCpcs) reinforced pure Al "proform wires" with high tensile strength have been developed by means of the continuous liquid metal infiltration method.
In this paper, using this method compatibilities of the fiber and various Al alloys as the matrices were investigated. The matrices used were Al based binary alloys contained each 5wt% of Si, Cu and Mg, and practical Al alloys such as A2024, A5052, A6061 and A7075. No wire with high strength was obtained in any matrix.
The results observed were precipitation of crystal Si on the surface of the SiC fiber in Al-5Si, Al-CuAl2 eutectic crystals coupling fibers in Al-5Cu, and diffusion layer of Mg into the fiber in Al-5Mg. They were considered to be the reasons of degradation of wire tensile strength. And also in the case of practical Al alloys similar tendencies were recognized.
From the experimental results, A1-3Cu-2Ni alloy was originally designed, and contact time of fiber and molten matrix during the infiltration were shortened. The tensile strength of the wire obtained was about 1.0GPa (at Vf 0.4) near the wire strength of pure Al matrix.
Consequently, it is concluded that compatibilities of SiCpcs fiber and Al alloys could be improved by adopting optimum processing variables and alloy compositions.
