Synthesis of Ultra-Incompressible Superhard Rhenium Diboride at Ambient Pressure

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Science

DOI:https://doi.org/10.1126/science.1139322· OSTI ID:930663

Chung, H; Weinberger, M; Levine, J; Kavner, A; Yang, J; Tolbert, S; Kaner, R

The quest to create superhard materials rarely strays from the use of high-pressure synthetic methods, which typically require gigapascals of applied pressure. We report that rhenium diboride (ReB{sub 2}), synthesized in bulk quantities via arc-melting under ambient pressure, rivals materials produced with high-pressure methods. Microindentation measurements on ReB{sub 2} indicated an average hardness of 48 gigapascals under an applied load of 0.49 newton, and scratch marks left on a diamond surface confirmed its superhard nature. Its incompressibility along the c axis was equal in magnitude to the linear incompressibility of diamond. In situ high-pressure x-ray diffraction measurements yielded a bulk modulus of 360 gigapascals, and radial diffraction indicated that ReB{sub 2} is able to support a remarkably high differential stress. This combination of properties suggests that this material may find applications in cutting when the formation of carbides prevents the use of traditional materials such as diamond.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 930663
• Report Number(s): BNL--81156-2008-JA
• Journal Information: Science, Journal Name: Science Vol. 316; ISSN 0193-4511; ISSN SCEHDK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATMOSPHERIC PRESSURE
COMPRESSIBILITY
CUTTING TOOLS
HARDNESS
RHENIUM BORIDES
SYNTHESIS
national synchrotron light source