Bimodal Microstructure and Mechanical Properties of Cryomilled Nanocrystalline A1-7.5Mg
Abstract
The microstructure and mechanical properties consisting of tensile behavior and hardness of bulk nanocrystalline Al-7.5Mg alloy were investigated. Grain refinement was achieved by cryomilling of atomized Al-7.5Mg powders and then nanocrystalline powders blended with 15% and 30% coarse-grained Al-7.5Mg powders were consolidated by hot isostatic pressing (HIP) followed by extrusion to produce bulk nanocrystalline Al-7.5Mg alloys. Bimodal structures which enhance ductility and toughness of nanocrystalline metals were produced that consisted of nanocrystalline grains and elongated coarse-grain bands Examination of indentation revealed unusual deformation mechanisms and interactions between the coarse-grain bands and nanocrystalline regions. The ductile coarse-grain bands underwent extensive plastic deformation near indentation while nanocrystalline regions exhibited limited deformation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2003
- Accession Number
- ADP014239
Entities
People
- David B. Witkin
- Enrique J. Lavernia
- Steven R. Nutt
- Zonghoon Lee
Organizations
- University of California, Irvine