Mechanical properties and oxidation behavior of SiCf/Ti3SiC2 composites prepared by hot isostatic pressing

SiCf /Ti3SiC2 composites were fabricated by hot isostatic pressing using Ti3SiC2 powder and SiCf as starting materials at 1200 degrees C for 2 h. A maximum flexural strength of 498 MPa and a fracture toughness of 6.76 MPa center dot m(1/2) were achieved for a composite with 5 vol% SiCf and the microhardness reached 1068 HV1 with 25 vol% SiCf. SiC and Ti3SiC2 are thermodynamically stable according to the Ti-Si-C phase diagram. However, microstructure analysis showed that the SiCf was distributed uniformly in the Ti3SiC2 matrix with an interfacial layer that was composed of TiC and SiC. Elemental Al agglomeration in the Ti3SiC2 matrix occurred in this reaction layer, which was considered the inducing factor for the occurrence of the interfacial reaction. The interfacial reaction was intense with a low fiber content. Oxidation testing suggested that the oxidation rate increased with SiCf introduction. The oxidation mass gain curve plateaued after 15 h.

Automated summary

SiCf/Ti3SiC2 composites were fabricated by hot isostatic pressing using Ti3SiC2 powder and SiCf as starting materials at 1200°C for 2 hours. The composites exhibited improved flexural strength and microhardness with increasing SiCf content, but also showed enhanced oxidation rate.