Accession Number:

ADA581756

Title:

Ductilization of High-Strength Magnesium Alloys

Descriptive Note:

Final rept. 1 Oct 2011-30 Jun 2012

Corporate Author:

NORTHWESTERN UNIV EVANSTON IL OFFICE OF RESEARCH SPONSORED PROJECTS

Personal Author(s):

• Olson, Gregory B.
• Zhang, Shengjun

Report Date:

2012-09-17

Pagination or Media Count:

61.0

Abstract:

A computational materials design approach is extended to high-strength Magnesium alloys to predict new compositions and novel multistep thermal processing to enhance ductility. Design modeling employing highly precise FLAPW all-electron DFT quantum mechanical calculations focus on the enhancement of grain boundary cohesion, based on the Rice-Wang thermodynamic model previously validated in high-performance steels. The calculations identify the cohesion enhancing potencies of grain boundary segregants as well as the segregation energies controlling grain boundary composition. The predicted surface thermodynamic parameters are integrated with bulk thermodynamics to predict novel alloy compositions and new thermal processing to optimize grain boundary composition in precipitation-strengthened alloys with enhanced ductility.

Descriptors:

• *DUCTILITY
• *GRAIN BOUNDARIES
• *HIGH STRENGTH ALLOYS
• *MAGNESIUM ALLOYS
• CHARGE DENSITY
• CLEAVAGE
• COHESION
• CRYSTAL STRUCTURE
• DENSITY FUNCTIONAL THEORY
• EMBRITTLEMENT
• MECHANICS
• PLANE WAVES
• QUANTUM THEORY
• SEGREGATION(METALLURGY)
• STRESS STRAIN RELATIONS
• THERMODYNAMICS

Subject Categories:

• Properties of Metals and Alloys
• Crystallography
• Mechanics
• Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE