Role of SPS temperature and holding time on the properties of Ti۳AlC۲-doped TiAl composites

In order to study the effects of sintering conditions on the properties of TiAl-based materials, two different compositions (TiAl-۱۵ wt% Ti۳AlC۲ and TiAl-۲۵ wt% Ti۳AlC۲) were chosen and manufactured by spark plasma sintering at ۹۰۰ ºC/۷ min and ۱۰۰۰ ºC/۱۵ min. The results showed that increasing the MAX phase content had a positive effect on the relative density and mechanical properties, but simultaneous increasing the temperature and holding time is more effective in the improvement of properties. For TiAl-۱۵ wt% Ti۳AlC۲ sample, the relative density, Vickers hardness, fracture toughness, and bending strength increased from ۹۲.۳%, ۳.۶ GPa, ۱۰.۹ MPa.m۱/۲, and ۲۰۶ MPa to ۹۵.۲%, ۴.۵ GPa, ۱۲.۰ MPa.m۱/۲, and ۳۳۶ MPa, respectively, as the sintering temperature and holding time increased from ۹۰۰ ºC/۷ min to ۱۰۰۰ ºC/۱۵ min. In the case of the TiAl-۲۵ wt% Ti۳AlC۲ sample, increasing the sintering temperature and holding time from ۹۰۰ ºC/۷ min to ۱۰۰۰ ºC/۱۵ min led to the improvement of relative density, Vickers hardness, fracture toughness, and bending strength from ۹۲.۸%, ۴.۱ GPa, ۱۱.۲ MPa.m۱/۲, and ۲۷۰ MPa to ۹۷.۵%, ۴.۶ GPa, ۱۱.۸ MPa.m۱/۲, and ۳۴۰ MPa, respectively.