Size Scale and Defect Engineered Nanostructures for Optimal Strength and Toughness
Abstract
The goal of this research project was to develop realistic combinations of ceramics and/or semiconductors that simultaneously achieve high hardness (>40 GPa) and toughness (>400 MPa*m1/2). While this is probably unrealistic for bulk material production due to inherent defects associated with processing, there is a very real opportunity for thin coatings in environments involving severe wear and/or dynamic penetration. This includes a wide range of industrial applications, including automotive, aircraft, electronics, manufacturing, and biomedical. To achieve this goal, the proposal outlined three primary objectives: (1) the development of physically based, dislocation models to understand the deformation of brittle materials, (2) the synthesis of model ceramic nanocomposites that demonstrate high hardness and toughness, and (3) the detailed understanding of the arrangements and types of dislocation structures in small volumes. This involved the uniaxial compression of Si nanovolumes (spheres and towers) using a combination of TEM in situ indentation and molecular dynamics simulations for objective (1), the deposition of Si-SiC core-shell nanotowers for objective (2), and the HR TEM analysis of deformed Si nanovolumes for objective (3). This report summarizes the substantial progress made on the first two of these objectives and the work that is currently underway to address objective (3).
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 07, 2011
- Accession Number
- ADA538707
Entities
People
- William W. Gerberich
Organizations
- University of Minnesota