Additional grain boundary strengthening in length-scale architectured copper with ultrafine and coarse domains. (May 2019)

• Record Type: Journal Article
• Authors: Hou, Xiaodong; Krauß, Sebastian; Merle, Benoit
• Is Part Of: Scripta materialia. Number 165(2019)
• Page Start: 55
• Page End: 59
• Publication Date: 2019-05
• Subjects: Grain boundary strengthening -- Crystal structure -- Hall-Petch effect -- Mechanical property testing -- Bimodal grained microstructure; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2019.02.019
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: 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. Graphical abstract: Unlabelled Image