Investigation of the microstructure and physical properties of TaSi2 sintered at high temperature and high pressure

Abstract

Tantalum disilicide (TaSi2) has been widely studied for its excellent physical properties such as high hardness, high temperature oxidation resistance and low resistivity. Here, we aim to investigate the effects of different sintering temperatures and pressures on the microstructure and physical properties of TaSi2 ceramics. We successfully prepared dense TaSi2 ceramics using high-pressure and high-temperature (HPHT) sintering techniques. Characterization results show that TaSi2 ceramic properties are strongly influenced by the sintering temperature. The density, Vickers hardness and fracture toughness of TaSi2 sintered samples reaches a maximum value of 9.182 g/cm3, 11.34 GPa and 11.97 MPa m1/2, respectively. The fracture toughness of TaSi2 sintered samples was significantly improved and also exhibited excellent high-temperature oxidation resistance. Meanwhile, we also investigated the microstructure and grain size variation of TaSi2 sintered samples with sintering conditions using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The results show that HPHT sintering can effectively refine the grains of TaSi2 ceramics. It provides effective data and ideas for more efficient utilization of TaSi2 and preparation of other high-performance ceramics.

Keywords

• Ceramics
• Fracture toughness
• Microstructures
• Vickers hardness
• Antioxidant properties