Room-temperature mechanical behavior of cryomilled Al alloys

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 37; no. 1; pp. 185 - 194
• Main Authors: WITKIN, David, HAN, Bing Q, LAVERNIA, Enrique J
• Format: Journal Article
• Language: English
• Published: New York, NY Springer 2006; Springer Nature B.V
• Subjects: Alloys; Applied sciences; Exact sciences and technology; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microstructure; Temperature; Tensile strength; Mechanical properties; Room temperature
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-006-0163-2

Room-temperature mechanical properties of cryomilled Al-7.5 pet Mg and Al 5083 alloys are discussed in the context of a duplex microstructure, which arises during processing. After consolidation via hot isostatic pressing ("hipping"), coarse-grained regions are formed in former interparticle void volumes, and these regions become elongated during extrusion. Comparison of tensile and compression testing results on both "as-hipped" and extruded materials shows that tension-compression asymmetry is the result of these coarse-grained regions and not necessarily a fundamental property of ultrafine grained Al. The strength of the extruded materials is consistent with the Hall-Fetch model of strengthening by grain size refinement, but the hipped material deviates from this trend, with a lower strength despite finer average grain size. This can also be attributed to the presence of coarse-grained regions, which subtract from the strength in a predictable manner and also enhance the ability of the cryomilled material to work harden. [PUBLICATION ABSTRACT]