Cyberalloys 2020: Naval Materials by Design
Abstract
Funds are provided to support the development of high-performance transformation-induced-plasticity alloys for structural applications.The investigators have organized their proposed activity into three main tasks.The first task is the dynamic design of blast and fragment protection steels. The investigators~ initial research focused on martensitic steels with optimized austenite dispersions for transformation toughening under impact conditions. Their initial experiments demonstrated the benefits of transformation strain hardening in enhancing biaxial uniform ductility for blast resistance, as validated in subscale water blast chamber tests. Later research investigated microvoid-softening-based shear localization mechanisms. Even more-recent research focused on austenitic steels optimized specifically for fragment protection via resistance to ballistic plugging failure, with validation by dynamic shear tests and analysis of fragment simulating projectile (FSP) penetration tests. The investigators plan to continue this activity, and integrate dynamic shear test results and quantum mechanical interfacial property predictions in the integrated design, fabrication, and evaluation of a next generation of optimized austenitic transformation-induced plasticity (TRIP) steels. The intent is to maximize the transformation interactions in order to optimized the properties for blast and fragment protection.The second task is the quantum engineering of interfaces. The investigators applied the highly-precise all-electron full-potential linearized augmented plane wave (FLAPW) density functional quantum mechanical method to predict the energetic and atomic configurations associated with fundamental metal/ceramic interfacial adhesion relevant to the optimization of steel grain refining dispersions. The objective was to increase the resistance to microvoid-driven shear localization in ductile fracture and ballistic penetration. The calculations focused on adhesion of body-centred-cubic iron relevant to martensitic steels. With the investigators~ new focus on austenitic steels, to better exploit the potential of transformation plasticity for further resistance to shear localization, they plan to continue their approach by examining the interfacial adhesion of applicable metal carbides onto face-centred-cubic iron for integration into the TRIP steel designs of task 1. As a second application of the FLAPW method, the investigators also plan to calculate the fundamental phase-stability parameters in titanium alloys for further enhancement of their databases supporting the titanium-alloy design efforts of task 3.The third task is the development of high performance marine titanium alloys. In a previous study, the investigators initiated thermodynamic modeling of the naval near-~ Ti-5111 plate alloy (nominal composition: Ti-5Al-1Sn-1Zr-1V-0.8Mo, wt.%) using the Thermotech TiDATA thermochemical database. The research included the development of atomic mobility and molar volume databases for titanium alloys using their rapid materials prototyping facility, a combined vacuum-hot-press and vacuum-quenching-furnace system that enables fast assembly and treatment of diffusion samples for microanalysis-based rapid determination of both multicomponent equilibrium phase-diagramme tie-lines and composition dependent diffusivities. The investigators plan to continue this activity, and integrate dynamic shear test results and quantum mechanical interfacial property predictions in the integrated design, fabrication, and evaluation of a martensitic-transformation-toughening titanium alloy, based on the Ti-5111 alloy, through optimization of the stability and transformation dilatancy of dispersed ~ phase in near-~ alloys.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141612400
Entities
People
- Gregory Olson
Organizations
- Northwestern University
- Office of Naval Research
- United States Navy