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 positive effect on the relative density and mechanical properties, but simultaneous increasing the temperature and holding time is more effective in 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 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.