Citation

Yong, Yik Seng and Chang, Yee Hui Robin and Low, Lay Chen and Lim, Thong Leng and Yoon, Tiem Leong (2022) Pressure-Induced Enhancement of Mechanical Performance in Zr-B System. In: 2nd FET PG Engineering Colloquium Proceedings 2022, 1-15 December 2022, Multimedia University, Malaysia. (Unpublished)

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Abstract

Background – A hard or superhard material is indispensable for use in heavy-duty wear applications, as well as material for high-temperature aerospace applications. Zirconium diboride (ZrB2) is categorized as a refractory transition metal boride and it is endowed with properties from ceramic and metallic. ZrB2 itself is classified as superhard and ultra-high temperature material. Purpose – ZrB2 in ambient pressure has been extensively studied, both experimentally and theoretically. However, in high pressure, very few studies have been conducted systematically. Design/methodology/approach – Using ab initio methodology, a comprehensive study has been carried out on the structural, electronic, mechanical, and thermal properties of ZrB2 under high pressures in increments of 10 GPa from atmospheric pressure to 100 GPa. Findings – Structural search via evolutionary algorithm has affirmed the existence of thermodynamically stable ZrB2 in all high-pressure cases. ZrB2 maintains the P6/mmm hexagonal lattice with no structural phase transformation at high pressures. The elastic constants and the elastic moduli of ZrB2 are found to increase steadily with the increase of surrounding pressure, connoting the superior mechanical and thermal characteristics of ZrB2. This can be seen in the increased hardness values, higher melting temperatures, and better machinability indices of ZrB2 with the increase in pressure. The predicted G/B and Poison’s ratios have both agreed that the brittle behaviour of ZrB2 is gradually reducing under high pressures. Research limitations – One of the main difficulties is that hardness is influenced by many factors, requiring comprehensive calculations to account for multiple length scales ranging from intrinsic to extrinsic hardness. Improvements in computational methodologies and access to high-performance computing clusters have provided essential insight into the mechanisms of deformation, as well as pinpointed some crystal chemical traits that generate high hardness. Originality/value – Despite the extensive theoretical and experimental studies, a few systematic analyses of zirconium diboride under high pressures are available. We expect these theoretical results of ZrB2, will be helpful for its heavy-duty wear resistance at very high temperatures, making it an excellent candidate for hypersonic flight or rocket propulsion systems.

Item Type:	Conference or Workshop Item (Other)
Uncontrolled Keywords:	Ab initio, Electronic structure, Elastic moduli, Hardness, Brittleness and ductility, Melting temperature
Subjects:	Q Science > QC Physics > QC170-197 Atomic physics. Constitution and properties of matter Including molecular physics, relativity, quantum theory, and solid state physics
Divisions:	Faculty of Engineering and Technology (FET)
Depositing User:	Ms Nurul Iqtiani Ahmad
Date Deposited:	15 Feb 2023 09:10
Last Modified:	15 Feb 2023 09:10
URII:	http://shdl.mmu.edu.my/id/eprint/10727

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