Abstract
The potential of TiAl as an elevated temperature material is well investigated. However, negligible room-temperature toughness and low high-temperature strength have limited its practical applications. To improve these properties, this compound was made as a composite material containing a second phase such as ceramics.
In the present study, using powder mixtures, combustion reaction was carried out to form in-situ intermetallic/ceramic composites in the Al-Ti-C, and Al-Ti-BN systems. As a result, the compact of Ti and Al with C(or BN) powder reacted exothermically to form TiAl and Ti2AlC(or Ti2AlN+TiB2). The resulting composites had a fine distribution of the Ti2AlC(or Ti2AlN+TiB2) in the matrix TiAl with a small amount of Ti3Al, and the volume fraction of these particles depended on the amount of C(or BN) present. Therefore, the processing technique in the present investigation is of interest as a new combustion reaction process to make in-situ intermetallic-based composite materials.
