Preparation of TiAl/Ti₂AlC composites with Ti/Al/C powders by in-situ hot pressing

Abstract

TiAl/Ti₂ AlC composites were prepared by in-situ hot pressing of Ti/Al/C powders mixtures and sintered at different temperatures were investigated by X-ray diffraction (XRD) of samples. The reaction procedure of Ti-Al-C system could be divided into three stages. Below 900°C, Ti reacts with Al to form TiAl intermetallics; above 900°C, C reacts with remain Ti to form TiC triggered by the exothermal reaction of Ti and Al; TiAl reacts with TiC to produce dense TiAl/Ti₂ AlC composites. In the holding stage, ternary Ti₂AlC develops to layered polycrystal and composites pyknosis in the meanwhile. The mechanism of synthesis and microstructure was especially discussed.

Keywords

Ti-Al-C system / TiAl/Ti₂AlC composites / in-situ hot pressing / microstructure

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