Fabrication of TiC coated short carbon fiber reinforced Ti3SiC2 composites: Process, microstructure and mechanical properties

The C-f/Ti3SiC2 composites were fabricated through spark plasma sintering (SPS) and hot isostatic pressing (HIP), TiC coated Cf and Ti3SiC2 powder were used as starting materials. The improved fracture toughness (K-IC) and Vickers hardness (HV1) of the TiC coated C-f/Ti3SiC2 composite fabricated by SPS were 7.59 MPa.m(1/2) and 7.28 GPa. On this foundation, taking the advantage of better sintering process of HIP, the highest K-IC and HV1 achieved 8.32 MPa.m(1/2) and 9.24 GPa with fiber content of 10 vol%, which increased by 40% and 65% compared with that of monolithic Ti3SiC2 . The reasonable control of reactive interface is the main factor for the improved mechanical properties of the composites, the TiC coating effectively protected the fiber structure from interfacial reaction compared with that of the non-coated Cf/Ti3SiC2 . Meanwhile, the artificially designed and weakly bonded TiC coated C-f can fully exert the toughening mechanisms like fiber pull-out and debonding.

Automated summary

TiC coated C-f/Ti3SiC2 composites were fabricated using SPS and HIP processes, exhibiting improved fracture toughness and Vickers hardness. The HIP process allows for better sintering and further enhances the mechanical properties of the composites. The control of reactive interface and the utilization of fiber pull-out and debonding mechanisms contribute to the improved properties.