Toughness Scale from First Principles

We correlate the experimentally measured fracture toughness of 24 metals and ceramics to their quantum mechanically calculated brittleness parameter. The brittleness parameter is defined as the ratio of the elastic energy density needed to spontaneously break bonds in shear versus in tension, and is a primitive-cell property. Under 300 GPa hydrostatic pressure, the model predicts that diamond has smaller brittleness than molybdenum at zero pressure, and thus should deform plastically without cracking at room temperature. Disciplines Engineering | Materials Science and Engineering Comments Suggested Citation: Ogata, S. and J. Li. (2009). "Toughness scale from first principles." Journal of Applied Physics. 106, 113534. © 2009 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. http://dx.doi.org/10.1063/1.3267158 This journal article is available at ScholarlyCommons: http://repository.upenn.edu/mse_papers/188 Toughness scale from first principles Shigenobu Ogata and Ju Li Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272, USA Received 26 May 2009; accepted 31 October 2009; published online 14 December 2009 We correlate the experimentally measured fracture toughness of 24 metals and ceramics to their quantum mechanically calculated brittleness parameter. The brittleness parameter is defined as the ratio of the elastic energy density needed to spontaneously break bonds in shear versus in tension, and is a primitive-cell property. Under 300 GPa hydrostatic pressure, the model predicts that diamond has smaller brittleness than molybdenum at zero pressure, and thus should deform plastically without cracking at room temperature. © 2009 American Institute of Physics. doi:10.1063/1.3267158