Light Weight, Low Cost Compositionally and Microstructurally Complex Alloys with Combinations of Strength, Ductility and Corrosion Resistance: Discovery, Design and Mechanistic Understandings
Abstract
Funds are provided to select, synthesize and characterize light weight, CLC2A~s, enhance mechanical properties of selected CLC2A~s to understand matrix and particle strengthening mechanisms, and establish understanding of composition and structure-based corrosion properties and mechanisms of light weight, CLC2A~s in marine environments. Specific tasks include: (1) employ and validate machine learning approach to identify the phase fields of all current 400+ CCAs, integrate semi-empirical descriptors with data-driven descriptors for machine learning for CCA-intermetallic precipitate composites and control nucleation and growth of precipitates, employ machine learning to discover compositionally complex intermetallics (CCIs) for enhanced properties, and iterate CCAs based on experimental feedback, and continue microstructure control of CCA composites; (2) study and review literature for the alloy design based on prospects for high corrosion resistance, develop understanding of microstructures and compositions via conducting thermodynamic assessment of oxide phases possible using stability diagrams and E-pH diagrams, and conduct initial rapid screening of selected generation 1 and 2 alloys; (3) conduct potential step repassivation studies on alloys selected to assess prospects for long term passivity, obtain information on various length scales regarding the oxides composition and phase identity on the selected alloys, and use findings to guide iterative alloy design; (4) systematically test isolated phases on selected alloys, conduct exposures in full immersion and simulated atmospheric tests, conduct mechanistic diagnostics studies as approach to elucidate origins and mechanisms of good corrosion resistance in a variety of pertinent aqueous environments and study subsequent prospects for passivity; (5) explore advanced corrosion protection strategies to achieve oxide enrichment with beneficial elements over various phases, study heat treatment to eliminate depletion profiles and suppression of cathodic kinetics by micro-alloy additions, and iterate as necessary to produce the final set of alloys with combinations of optimal properties
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 13, 2019
- Source ID
- N000141912420
Entities
People
- John R. Scully
Organizations
- Office of Naval Research
- United States Navy
- University of Virginia