Synthesis, microstructure, and mechanical properties of MAX phase Ti2GaC ceramics with V doping

Ti2GaC is a novel ternary layered ceramic with unique physical and chemical properties such as excellent thermal conductivity, low density, high-temperature oxidation resistance, and corrosion resistance. However, the relatively low strength and hardness of Ti2GaC hinder its practical applications as a structural component. To strengthen the mechanical properties of Ti2GaC and extend its application range, in this study, (Ti1-xVx)2GaC MAX phase solid solutions with x ranging up to 0.25 were successfully synthesized using a two-step sintering method. (Ti1-xVx)2GaC solid solutions grains showed a typical lamellar structure, where the a lattice constant of (Ti1-xVx)2GaC decreased from 3.0660 to 3.0326 Å and c decreased from 13.3223 to 13.1520 Å. The effects of V content on the solid solution microstructure, crystal structure, mechanical strength, and resistance to friction and wear were evaluated in detail. In addition, the solid solution formation mechanism and fracture damage modes of these materials were discussed. The crystal structure, mechanical properties, electronic properties, and chemical bonding of (Ti1-xVx)2GaC continuous solid solution at x = 0–1 were calculated by DFT. The solid solution enhancement mechanism of (Ti1-xVx)2GaC was explained by analyzing the relationship between the structure and properties.