Abstract
Polymer derived SiC fiber reinforced Al "preform wires" were used as semi-finished materials for fabricating composites by hot-pressing. The influence of combination of pressure, heating temperature and holding time during hot-pressing on strength, microstructure and fracture surface of fabricated composites was investigated.
Pressure below 30 MPa and pressing time shorter than 300 s were not enough to bond preform wires each other. Pressing time longer than 1.8 ks degradated fiber strength. The combination of pressure of 40 MPa or more and pressing time of 600 s through 1.2 ks resulted in high strength of composites. Under such conditions, pressing temperature below 788 K was too low to bond preform wires each other, while pressing temperature above 833 K lead to fiber damage due to interfacial reaction between SiC fibers and aluminum matrix.
Consequently, the pressing temperature from 803 K through 823 K was suitable to make high strength composites. The composites fabricated under the conditions described above showed very high tensile strength, which was about 95 pct of that of the preform wires.
It can be concluded that metal matrix composites can be easily fablicated using preform wires as semifinished materials.
