Microstructure and mechanical properties of short-carbon-fiber/Ti3SiC2 composites

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