Role of SPS temperature and holding time on the properties of Ti3AlC2-doped TiAl composites

Abstract

In order to study the effects of sintering conditions on the properties of TiAl-based materials, two different compositions (TiAl-15 wt% Ti3AlC2 and TiAl-25 wt% Ti3AlC2) were chosen and manufactured by spark plasma sintering at 900 ºC/7 min and 1000 ºC/15 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-15 wt% Ti3AlC2 sample, the relative density, Vickers hardness, fracture toughness, and bending strength increased from 92.3%, 3.6 GPa, 10.9 MPa.m1/2, and 206 MPa to 95.2%, 4.5 GPa, 12.0 MPa.m1/2, and 336 MPa, respectively, as the sintering temperature and holding time increased from 900 ºC/7 min to 1000 ºC/15 min. In the case of the TiAl-25 wt% Ti3AlC2 sample, increasing the sintering temperature and holding time from 900 ºC/7 min to 1000 ºC/15 min led to the improvement of relative density, Vickers hardness, fracture toughness, and bending strength from 92.8%, 4.1 GPa, 11.2 MPa.m1/2, and 270 MPa to 97.5%, 4.6 GPa, 11.8 MPa.m1/2, and 340 MPa, respectively.