Plasticity in titanium alloys as predicted from discrete dislocation dynamics modeling
Abstract
Dual phase titanium alloys have high specific modulus, specific strength, and excellent corrosion resistance properties. Accordingly, they are of great interest for many naval, aerospace, energy and biomedical applications. Nevertheless, the high cost of fabricating conventional components from titanium alloys has limited their widespread use as compared to other metals. Recently, the U.S. Navy has initiated a thrust towards reducing the cost and time to produce titanium alloy components in their near-to-final shape through additive manufacturing techniques. However, the type of processing technique can have a significant effect on the resulting microstructure, which subsequently affects the properties of the alloy. The prediction of the mechanical properties as a function of the microstructure remains a major challenge for the selection of the right additive manufacturing technique along with microstructure optimization for a specific component that will be exposed to specific loading and environmental conditions. Multiscale modeling and simulation tools can significantly boost the process of design and optimization of AM metallic parts, which is at the heart of the integrated computational materials engineering (ICME) initiative. The primary objectives of the current proposal are to fundamentally understand the effect of slip transition across alpha/beta interfaces as well as the effect of size and relative crystallographic orientation between the two phases in dual phase titanium alloys on the mechanical properties (including yield strength, hardening, and rate sensitivity) using large scale three-dimensional discrete dislocation dynamics simulations that explicitly model the discrete dislocation interactions and transfer across interfaces. These results will provide valuable inputs to upper length scale simulations (e.g. crystal plasticity models), which would subsequently lead to more accurate predictions of the microstructure-properties relationships at the component level. This proposal will thus provide substantial understanding of the deformation and damage localization in dual phase titanium alloys, which will subsequently lead to the development of microstructurally-based reliable predictive models for damage evolution and component life. All of these aspects are of critical importance for the mission of the U.S. Navy. Although the methods and techniques developed under this proposal are focused on studying dual phase titanium alloys, the wealth of knowledge resulting from this work can be applied to other types of material systems of interest.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 19, 2018
- Source ID
- N000141812858
Entities
People
- Jaafar A El-Awady
Organizations
- Johns Hopkins University
- Office of Naval Research
- United States Navy