Interfacial products in SiC fiber reinforced Ti-Al based intermetallic alloys

Abstract

Continuous SiC fiber reinforced Ti-Al based intermetallic alloys were prepared by sintering pure Ti and Al foils as well as SiC fibers. Owing to a complex self-propagating combustion reaction and diffusion reactions occurring during sintering process, the emphasis of the present paper is on identifying the interfacial products between SiC fibers and matrix, which is crucial for the mechanical properties of the sintered materials. Microstructure observation reveals that the sintered alloys contain lamellar matrix and SiC fibers with various interfacial products. The lamellar matrix compose chicly of TiAl3, TiAl2, TiAl, Ti3Al and α-Ti phases, the SiC fibers locate in TiAl3/TiAl layer and/or Ti3Al/α-Ti layer. The Al content is very little in the interfacial reaction zone. The main interfacial products are considered to mainly be compounds of Ti5Si3Cx, Ti3AlC, and Al4C3Six, etc. The interfacial reaction layer in the Ti-rich phase (Ti3Al and α-Ti) is thicker than in the Al-rich phase layer (TiAl3, TiAl2 and TiAl).