High-performance copper-matrix materials reinforced by nail board-like structure 2D Ti₃C₂T_x MXene with in-situ TiO₂ particles

Two-dimensional (2D) nanomaterials based on MXenes have gained increasing importance in the field of strength reinforcement. However, the easy oxidation of MXenes has long been deemed unfavorable for reinforcement in high-temperature processing. Herein, high-shear mixing was used in present work for simple and efficient dispersion of MXenes in copper powders. Partial MXene sheets were also in-situ oxidized to TiO₂ particles to form nail board-like structure reinforcement (NSR) during spark plasma sintering (SPS) process at 600 °C, which allowed one to significantly improve the yield strength of copper matrix by up to 70.3%. Experimental characterization and modeling simulations enabled one to identify second phase strengthening as the main reason for increased yield strength of the composites. In particular, the mechanical engagement of NSR played an important role in strengthening. Meanwhile, the hardness of TiO₂ particles on NSR was found to be higher than that of the copper matrix, leading to enhancement in compressive yield strength. Also, the presence of MXene sheets on NSR slightly reduced the resistance of copper matrix composites. In sum, these findings look promising for designing novel MXene reinforced metal matrix composites with improved mechanical properties.