Microstructure evolution of SiC_p/Al-Ti foils during hot rolling and reaction annealing

PANG Jin-cheng, FAN Guo-hua, LI Ai-bin, GENG Lin

(School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China)

Abstract:SiC_p/Al-Ti foils were prepared by hot-pressing and hot rolling. The diffusion reaction between Ti and SiC_p/Al was investigated and multi-layers of intermetallics formed during reaction annealing at 1 200 °C. The microstructure and the composition in each intermetallic layer were characterized using scanning electron microscope (SEM) equipped with energy dispersive spectroscope (EDS). The products from the reaction between SiC and titanium aluminides were determined by X-ray diffractometer (XRD) and the thermodynamics of the reaction was investigated using differential thermal analysis (DTA). The results show that different reactive layers form in the sample and SiC particles disappear with the formation of intermetallic layers after annealing. Intermetallic multi-layers are determined to be Ti₃Al, TiAl and TiAl₃. SiC particles react with titanium aluminide during reaction annealing to form Ti₃AlC, TiC, Ti₅Si₃ and Ti₃SiC₂.

Key words:titanium aluminide; diffusion reaction; SiC; composite