Microstructure and mechanical properties of titanium matrix composites reinforced with organic-derived ceramic phases via spark plasma sintering

In this study, TiC/(TA15-Si) composites were fabricated using a solution coating method combined with spark plasma sintering (SPS), with polycarbosilane (PCS) and TA15 alloy powder as raw materials. The results show that when the sintering temperature exceeds 1000 °C, the decomposition products of PCS react with the matrix to form in-situ TiC particles distributed in a quasi-continuous manner, while Si fully dissolves into the TA15 matrix. At a sintering temperature of 1100 °C, the composite exhibits optimal microstructure and tensile properties at room temperature. The matrix displays an α+ β lamellar structure, with the α+ β colony size refined from 108.3 μm in TA15 alloy to 25.5 μm in the composite. The composite achieves a yield strength and tensile strength of 1124 MPa and 1221 MPa, respectively, representing increases of 27.0 % and 24.5 % compared to the TA15 alloy (885 MPa and 981 MPa). Furthermore, the tensile strengths of the composite at 600 °C, 650 °C, and 700 °C are 614 MPa, 504 MPa, and 355 MPa, respectively, showing enhancements of 29.3 %, 26.6 %, and 17.2 % compared to the TA15 alloy (475 MPa, 398 MPa, and 303 MPa).