Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 29, 2019
Previous Article Next Article

Designing ultrastrong 5d transition metal diborides with excellent stability for harsh service environments

Author affiliations

Abstract

Much effort was devoted towards the rational design of ultrastrong transition metal borides (TMBs) with remarkable mechanical properties and excellent stabilities, owing to promising applications in machining, drilling tools and protective coatings for the aerospace industry. Although an enormous number of investigations have been performed on these TMBs under normal conditions, studies on the stability and mechanical strength in harsh high-pressure environments, which are critical for safe service behavior and a realistic understanding of stabilities and strengthening mechanisms, are yet nearly absent. In this work, taking 5d TMB2 (TM = Hf, Ta, W, Re, Os, Ir and Pt) as an illustration, we performed comprehensive high-throughput first-principles screening for thermodynamically stable and metastable structures under various pressures. Four experimentally observed structures are found to be thermodynamically feasible for most 5d TMB2 (TM = Hf, Ta, W, Re, Os and Ir) at 0 and 100 GPa. By exploiting orbital-decomposed electronic structures, we reveal that the pressure-induced stabilization and phase transitions of 5d TMB2 can be rationalized by the splitting of bonding and antibonding states around the Fermi level. Further investigations on the pressure-induced strengthening indicate that 5d TMB2 in the hP6[194] structure exhibit a profound strengthening effect under high pressure, which can be rationalized by the proposed strengthening factor η, but η fails in the oP6[59] structure due to the changed instability modes at different pressures. These findings suggest the necessity to explore the plasticity parameters for a realistic understanding of pressure-induced strengthening in TMBs, providing a strong argument for rules based on bond parameters at equilibrium in designing strong solids.

Graphical abstract: Designing ultrastrong 5d transition metal diborides with excellent stability for harsh service environments

Back to tab navigation

Supplementary files

Article information


Submitted
20 May 2019
Accepted
01 Jul 2019
First published
01 Jul 2019

Phys. Chem. Chem. Phys., 2019,21, 16095-16107
Article type
Paper

Designing ultrastrong 5d transition metal diborides with excellent stability for harsh service environments

N. Wang, Z. Fu, D. Legut, B. Wei, T. C. Germann and R. Zhang, Phys. Chem. Chem. Phys., 2019, 21, 16095
DOI: 10.1039/C9CP02847A

Social activity

Search articles by author

Spotlight

Advertisements