Additional grain boundary strengthening in length-scale architectured copper with ultrafine and coarse domains

SCRIPTA MATERIALIA

卷:165

Article

Hou, Xiaodong^1,2  Krauss, Sebastian³  Merle, Benoit³ 

[1] Coventry Univ, Res Inst Future Transport & Cities, Priory St, Coventry CV1 5FB, W Midlands, England

[2] Ctr Excellence Adv Mat, Songshan Lake 523808, Dongguan, Peoples R China

[3] Univ Erlangen Nurnberg FAU, Inst 1, Dept Mat Sci & Engn, Martensstr 5, D-91058 Erlangen, Germany

关键词: Grain boundary strengthening;    Crystal structure;    Hall-Petch effect;    Mechanical property testing;    Bimodal grained microstructure;   

DOI  :  10.1016/j.scriptamat.2019.02.019

来源: Elsevier

【 摘 要 】

The strength of polycrystals is known to increase with decreasing grain size, known as Hall-Petch effect. However, this relationship fails to predict the strength of samples with a non-uniform distribution of grain sizes. In this study, we purposely designed and fabricated copper micropillars with a strongly bimodal microstructure: half volume consisted of a large number of ultrafine grains, while the other half was predominantly single-crystalline. Micropillar compression evidenced that bimodal samples are 35% stronger than their counterparts containing only ultrafine grains. This paradoxical finding highlights the greater strengthening potential of microstructure distribution engineering, compared to the traditional grain refinement strategy. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free