High Pressure and Large Shear Deformation System for Materials Research
Abstract
Processes under high pressure and large plastic deformations are common in material synthesis and technologies and behavior of ceramics during projectile penetration. High pressure causes phase transformations (PTs) in solids, which are studied in a diamond anvil cell (DAC). The superposition of plastic deformation on high pressure in a rotational DAC (RDAC) drastically affects PTs. Thus, plastic shear: (a) reduces the PT pressure by a factor of 2-10; (b) promotes the formation of novel phases; (c) substitutes reversible PTs with irreversible PTs, and (d) leads to amorphous and nanostructured materials. This proposal is crucial to our capability at Iowa State University to initiate experimental work on behavior of DoD-related materials (e.g., strong ceramics) under high pressure and large deformations. We are currently completing two DoD-funded projects: ARO W911NF-12-1-0340: ÒStrain-Induced Phase Transformations in Ceramics under High PressureÓ and DARPA W31P4Q-13-1-0010: ÒNew Pathways toward Metastable Solids through Moderate Pressure and Large Plastic Shear: Multiscale Simulations and Experiments.Ó Similar pressure-shear research was supported by ARO W911NF-09-1-0001: ÒPhase Transformations in Ceramics under Compression and ShearÓ and HDTRA1-09-1-0034: ÒSearch for New Highly Energetic Phases under Compression and Shear.Ó As a continuation of these efforts and after receiving acceptance of the white paper, we submitted an ARO proposal ÒPhase transformation-related phenomena under compression and shear of ceramics.Ó In all previous projects we performed theoretical and computational work while experiments were performed by our collaborator. This DURIP proposal is directed towards building a high-pressure laboratory at ISU. A new, dedicated RDAC will be designed and constructed, as well as, complemented with equipment to monitor sample loading and precise alignment. A complete optical spectroscopy system will be integrated for measurement of the pressure and displacement fields and Raman spectroscopy. This will allow us to develop coupled experimental/computational methods of material characterization and search for new materials and phenomena.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 16, 2018
- Source ID
- W911NF1710196
Entities
People
- Valery I. Levitas
Organizations
- Army Contracting Command
- Iowa State University
- United States Army