Affiliation:
1. Department of Mechanical Engineering, University of Alberta, Edmonton, AB T6G 2R3, Canada
Abstract
Boron carbide plays a crucial role in various extreme environment applications, including thermal barrier coatings, aerospace applications, and neutron absorbers, because of its high thermal and chemical stability. In this study, the temperature-dependent elastic stiffness constants, thermal expansion coefficient, Helmholtz free energy, entropy, and heat capacity at a constant volume (Cv) of rhombohedral B4C have been predicted using a quasi-harmonic approach. A combination of volume-dependent first-principles calculations (density functional theory) and first-principles phonon calculations in the supercell framework has been performed. Good agreement between the elastic constants and structural parameters from static calculations is observed. The calculated thermodynamic properties from phonon calculations show trends that align with the literature. As the temperature rises, the predicted free energy follows a decreasing trend, while entropy and Cv follow increasing trends with temperature. Comparisons between the predicted room temperature thermal expansion coefficient (TEC) (7.54×10−6 K−1) and bulk modulus (228 GPa) from the quasi-harmonic approach and literature results from experiments and models are performed, revealing that the calculated TEC and bulk modulus fall within the established range from the limited set of data from the literature (TEC = 5.73–9.50 ×10−6 K−1, B = 221–246 GPa). Temperature-dependent Cijs are predicted, enabling stress analysis at elevated temperatures. Overall, the outcomes of this study can be used when performing mechanical and thermal stress analysis (e.g., space shielding applications) and optimizing the design of boron carbide materials for elevated temperature applications.
Funder
the Natural Sciences and Engineering Research Council of Canada Discovery Grant
the George Ford Chair in Materials Engineering
Reference91 articles.
1. Pressureless sintering of boron carbide;Roy;Ceram. Int.,2006
2. Static and dynamic compression strength of hot-pressed boron carbide using a dumbbell-shaped specimen;Swab;J. Mater. Sci.,2017
3. Flexural strength, fracture toughness, and hardness of silicon carbide and boron carbide armor ceramics;Speyer;Int. J. Appl. Ceram. Technol.,2010
4. Some properties of single-crystal boron carbide;Werheit;J. Solid State Chem.,2004
5. Matkovich, V.I., Samsonov, G.V., and Hagenmuller, P. (1977). Boron and Refractory Borides, Springer.
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