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 degrees 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 degrees C, the composite exhibits optimal microstructure and tensile properties at room temperature. The matrix displays an alpha+ beta lamellar structure, with the alpha+ beta colony size refined from 108.3 mu m in TA15 alloy to 25.5 mu m 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 degrees C, 650 degrees C, and 700 degrees 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).