Microstructure evolution of TiAl matrix in the process of magnetron sputtering and hot isostatic pressing for fabricating TiAl/SiCf composites

The microstructures of titanium aluminides matrix based on TiAl both in matrix-coated fiber and in fiber-reinforced composites were studied in this paper. The titanium aluminides matrix was examined by means of scanning electron microscope, X-ray diffractometer and transmission electron microscope. The results show that, in sputtering process, amorphous phase forms firstly, and α-Ti(Al) + TiAl3 form later. Subsequently, during hot isostatic pressing, the amorphous phase, α-Ti(Al) and TiAl3 in the matrix-coated fibers transform into γ-TiAl and α2-Ti3Al in the composites.