Research Area 11.1: HCP Mg Alloys Formable at Room Temperature
Abstract
The technical objective of the proposed effort is to create new Mg-based alloys with superior room temperature ductility and formability. The proposed effort is motivated by a recent preliminary results demonstrating that, after certain heat-treatments, precipitates formed in Mg-Ca-Zn ternary system provide remarkable room-temperature ductility. The proposed effort will seek to quantify the relationship between heat treatment, density, size, composition and structure of nano-sized precipitates, and the resulting mechanical properties (strength and ductility) of the resulting alloys. Microstructure and precipitates will be studied systematically through optical and electron microscopy, X-ray diffraction, and 3D atom probe tomography, along with mechanical property measurements. Mg alloys will be hot isostatically pressed (HIPed) to reduce the porosity, homogenized in inert atmosphere in the solidus phase field, water-quenched, and then aged at various temperatures selected from the phase diagram to form nanosized coherent precipitates for strengthening and ductilization. Vickers microhardness measurements and simple bending tests will be used to determine the aging temperature-time combination that gives optimal strength and ductility. The most promising specimens will be selected for detailed characterization of mechanical properties and microstructure. Tensile testing will be performed on the most promising specimens, and the results will then be correlated with the corresponding microstructure as determined by optical, electron, and atom-probe tomographic microscopies and X-ray diffraction. The proposed studies will allow not only to determine composition and heat treatment resulting in Mg alloys with optimum combination of strength and ductility, but also lead to fundamental scientific understanding of how precipitate structure and composition may be related to these improved properties.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1610294
Entities
People
- Semyon Vaynman
Organizations
- Army Contracting Command
- Northwestern University
- United States Army