High strengthening effects and excellent wear resistance of Ti3Al(Si)C2 solid solutions

Abstract

AbstractThe Ti3Al1.2−xSixC2 (x = 0, 0.2, 0.4) powders were synthesized from Ti, Al, Si, and TiC powders, and nearly pure Ti3Al1.2−xSixC2 bulks were fabricated by the means of two‐time hot‐pressing method. Significant strengthening effect in bulks was found after the addition of 0.2 Si and 0.4 Si to form Ti3Al(Si)C2 solid solutions. The flexural strengths of Ti3AlSi0.2C2 and Ti3Al0.8Si0.4C2 were 485 and 554 MPa, 14% and 30% larger than the strength of Ti3AlC2, respectively. The Vickers hardness of these compounds were separately, 6.95 and 7.57 GPa, representing the enhancements of 37% and 49% over those of Ti3AlC2. The tribological behavior was studied by dry‐sliding method with a S45C steel at the sliding speed of 30 m/s and the normal load of 20‐80 N. The results showed that after incorporating different contents of Si, the friction coefficient was between 0.22 and 0.30, correspondingly lower wear rate was 3.19‐2.61 × 10−6 mm3/Nm. These excellent tribological performances were attributed to the presence of continuous self‐generated oxidized films during tribological examination. Finally, the phase compositions and microhardness of the oxidized films were analyzed and characterized.