Accession Number : ADA573756


Title :   PECASE - First Principles Modeling of Mechanics and Chemistry of Materials


Descriptive Note : Final rept. 1 May 2008-30 Nov 2012


Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA DEPT OF MATERIALS SCIENCE AND ENGINEERING


Personal Author(s) : Li, Ju


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a573756.pdf


Report Date : 18 Jan 2013


Pagination or Media Count : 14


Abstract : Recent experiments on nanostructured materials, such as nanoparticles, nanowires, nanotubes, nanopillars, thin films, and nanocrystals have revealed a host of ultra-strength phenomena, defined by stresses in a material component generally rising up to a significant fraction 1/10th of its ideal strength the highest achievable stress of a defect-free crystal at zero temperature. While conventional materials deform or fracture at sample-wide stresses far below the ideal strength, rapid development of nanotechnology has brought about a need to understand ultra-strength phenomena, as nanoscale materials apparently have a larger dynamic range of sustainable stress ( strength ) than conventional materials. Ultra-strength phenomena not only have to do with the shape stability and deformation kinetics of a component, but also the tuning of its physical and chemical properties by stress. Reaching ultrastrength enables elastic strain engineering , where by controlling the elastic strain field one achieves desired electronic, magnetic, optical, phononic, catalytic, etc. properties in the component, imparting a new meaning to Feynman s statement there s plenty of room at the bottom .


Descriptors :   *CHEMICAL PROPERTIES , *MECHANICAL PROPERTIES , *NANOWIRES , GRAPHENE , HIGH TEMPERATURE , MOLECULAR DYNAMICS , SOLID STATE CHEMISTRY , TRANSMISSION ELECTRON MICROSCOPY


Subject Categories : Physical Chemistry
      Electrical and Electronic Equipment
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE