Investigation on microstructure and mechanical properties of short-carbon-fiber/Ti3SiC2 composites

Abstract

In this paper, short-carbon-fibers (Csf) reinforced Ti3SiC2 matrix composites (Csf/Ti3SiC2, the Csf content was 0, 2, 5 and 10 vol.%) were fabricated by spark-plasma-sintering (SPS) using Ti3SiC2 powders and Csf as starting materials at 1300 oC. The effects of Csf addition on the phase compositions, microstructures and mechanical properties (including hardness, flexural strength and fracture toughness) of Csf/Ti3SiC2 composites were investigated. The Csf, with a bi-layered transition layers, i.e. TiC and SiC layer, were homogeneously distributed in the as-prepared Csf/Ti3SiC2 composites. With the increase of Csf content, the fracture toughness of Csf/Ti3SiC2 composites increased, but the flexural strength decreased, while the Vickers hardness decreased initially then increased steadily when the Csf content was higher than 2 vol.%. These changed performances could be attributed to the introduction of Csf and the formation of much stronger interfacial phases.