High-Entropy Borides under Extreme Environment of Pressures and Temperatures

Area of Science:

• Materials Science
• Solid State Physics
• High-Pressure Science

Background:

• High-entropy borides (HEBs) are advanced materials with potential for extreme condition applications.
• Their random distribution of multiple metallic elements offers unique properties.

Purpose of the Study:

• Investigate the theoretical and experimental properties of HEBs under extreme pressure and temperature.
• Evaluate HEBs for structural applications in nuclear and aerospace fields.

Main Methods:

• Theoretical modeling using special quasi-random structures for elastic properties.
• Synthesis of HEB samples under high pressure and temperature.
• Experimental characterization using large-volume pressure cells and diamond anvil cells with X-ray diffraction.

Main Results:

• Predicted bulk modulus of 288 GPa and shear modulus of 215 GPa at ambient conditions.
• Experimentally determined bulk modulus of 276 GPa, agreeing well with theoretical predictions.
• Measured compressive yield strength of 28 GPa at 65 GPa, indicating high strength at high pressures.

Conclusions:

• HEBs demonstrate exceptional phase stability and high compressive strength under extreme conditions.
• The excellent agreement between theoretical and experimental results validates the predictive power of the models.
• HEBs are highly suitable for structural material applications in nuclear and aerospace industries.