Application of dynamic dislocation-defect analysis to materials engineering practice

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Dynamic dislocation-defect analysis (DDDA) is a newly developed method [1], the basic notion of which is to use the mobile dislocations, which permits plastic deformation in crystalline matter, to sort out the types of obstacles it encounters in its passage through the crystalline matrix. By testing various well- defined microstructures, the specific thermodynamic signatures have been delineated. To transform this methodology into a predictive R&D technology, the DDDA must be correlated to microstructural kinetics: (a) by quantitative modelling as a function of time and temperature during alloy heat treatment and/or metal processing and (b) by correlation to the size and distribution of the evolving particles to the strength and ductility of that metallurgical state. This work primarily entails modelling of known mechanisms with respect to the DDDA signatures using a simple spreadsheet format to interpret the atomic mechanisms responsible for the development of specific microstructures. The boundary conditions for this modelling of the growth and dissolution of precipitates are provided by previous and on-going work in this laboratory and supplementary studies from the literature. This modelling was performed by two summer undergraduate assistants and in discussion with my plasticity theory colleagues at Waterloo University concluded it would be a good project for their coop-intern program. Negotiations are in progress.The long-term objective of this proposal is to complete this compilation in sufficient cases of industrial interest such that the application of this new technology will spread to every R&D centre in the world. We believe that, with the our current up-dating of the servo-hydraulic system and software, the microstructure of any metal sheet product can be assessed to examine if its material processing history can be optimized to result in enhanced properties of structure-strength-ductility. To globally communicate this knowledge, workshops and materials-testing training courses will be offered on a cost recovery basis.