Synthesis of Zr ₂ AlC MAX phase via spark plasma sintering (SPS): Influence of starting powders stoichiometry and sintering temperature on mechanical and wear properties

The synthesis of MAX phases has been extensively investigated over the past two decades due to their unique mechanical and tribological properties. Theoretical calculations showed that Zr-based MAX phases possess a remarkable hardness and elastic modulus. Therefore, their fabrication is an interesting topic. MAX phases with the highest content of Zr 2 AlC phase can hardly obtained. Simultaneous synthesis and sintering of Zr 2 AlC MAX phases are a challenging issue. In this research, Zr 2 AlC was prepared through spark plasma sintering using different stoichiometries of ZrH 2 :Al:C, at 1100°C, 1225°C, and 1300°C. The optimum sintering condition for achieving a MAX phase with high amount of Zr 2 AlC (69.9 wt.%) was obtained by the stoichiometry of 2:1.3:0.95, at 1300°C, 30 min. Physical properties (density, porosity, and phase content) as well as hardness, and tribological properties of the sintered samples were also investigated through XRD, SEM, and EDS analysis. The stoichiometry of 2:0.8:1.2 showed the highest wear resistance.