Bulk nanostructured Al-Si alloy with remarkable improvement in strength and ductility. (August 2021)

• Record Type: Journal Article
• Authors: Liu, Maowen; Zheng, Ruixiao; Xiao, Wenlong; Li, Jin; Li, Guodong; Peng, Qiuming; Ma, Chaoli
• Is Part Of: Scripta materialia. Number 201(2021)
• Publication Date: 2021-08
• Subjects: Al-Si alloys -- Nanostructured materials -- High-pressure solution treatment -- High-pressure torsion -- Mechanical properties; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2021.113970
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Refinement of microstructure for metallic materials alloyed by low-soluble elements has always been a difficult task. Here we propose a novel two-step route to achieve this goal, which has been successfully applied to a hypoeutectic Al-Si alloy. Al-Si single-phase alloy first prepared by solution treatment under ultra-high isostatic pressure was then subjected to high-pressure torsion, obtaining a bulk nanostructured hypoeutectic Al-Si alloy for the first time. The ultrafine Al grains, Si nano-particles, concentrated Si solutes and dislocations greatly contributed to the yield strength. Meanwhile, the brittle fracture of micrometer-sized Si phase in common Al-Si alloys was avoided by refining Si to nanoscale, and the ductility was significantly enhanced. Consequently, the nanostructured Al-Si alloy exhibited a high yield strength of 403 MPa and a large total elongation of 32%. This work provides a promising approach for realizing bulk nanostructured alloys with low-soluble components. Graphical abstract: Image, graphical abstract