Interfacial reaction and matrix microstructure evolution of SiCf/Ti2AlNb composites induced by hot isostatic pressing

The performance of continuous SiC fiber-reinforced titanium matrix composites (SiCf/Ti) is highly dependent on the interfacial reaction layer (RL) and the microstructure of the matrix. In this study, SiCf/Ti2AlNb precursor wires were fabricated using magnetron sputtering, and SiCf/Ti2AlNb composites were produced via hot isostatic pressing (HIP). The study explored the interfacial reactions and matrix microstructure evolution induced by HIP. It was found that the precursor wires interface mainly consisted of a TiC layer with an average thickness of 43.31 +/- 8.17 nm, while the matrix exhibited a uniform elemental distribution and a complex nano-scale structure composed of O, B2, and alpha(2) phases. After HIP, elemental diffusion occurred at the interface, forming a multilayer structure that included fine-grained TiC, coarse-grained TiC, and alpha(2) layers, with thicknesses of 53.79 +/- 12.03 nm, 0.46 +/- 0.03 mu m, and 0.45 +/- 0.05 mu m, respectively. The matrix evolved into a micron-scale O+B2+alpha(2) phase structure, with lath-O phase precipitates observed in the B2 phase. The enrichment of matrix elements was attributed to self-diffusion of matrix elements (leading to the formation of a micron-scale phase structure). These findings provide valuable insights into the structural transformation and interfacial evolution of SiCf/Ti2AlNb composites under HIP conditions.