Abstract

In the light of unique and anomalous properties of ultrafine grained (UFG) alloys, an effort was made to develop a predictive capability of the yield strength (YS) of UFG Al-Mg-Sc alloy. UFG microstructure was introduced using friction stir processing. Microstructural characterization of grain size, dislocations, and nano-sized Al3(Sc,Zr) particles was carried out using electron backscatter diffraction and transmission electron microscope. The contribution from Peierls-Nabarro stress, solid solution strengthening, precipitation strengthening, grain boundary strengthening, and dislocation strengthening were assessed using existing strengthening models. Additivity law to predict the YS of the alloy was chosen based on the microstructural state of the alloy. The microstructural state of coarse grained and UFG alloy favored the use of linear additivity rule over Pythagorean. The use of a mixed (linear and Pythagorean) additivity rule was also carried out to assess its YS prediction capability. A difference in the range of 33-55% was observed between predicted and experimentally obtained YS for UFG alloy. The reason was related to the overprediction from grain boundary strengthening model. A smaller HP slope than the normal slope value was able to predict the YS of the UFG alloy more closely. © 2013 Elsevier B.V.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Al alloys; Friction stir processing; Strengthening mechanisms; Ultrafine grained materials

International Standard Serial Number (ISSN)

0921-5093

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Elsevier, All rights reserved.

Publication Date

05 Sep 2013

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Metallurgy Commons

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