Acta Metallurgica Sinica (English Letters) ›› 2022, Vol. 35 ›› Issue (12): 2014-2026.DOI: 10.1007/s40195-022-01432-4

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Toughening Effects through Optimizing Cell Structure and Deformation Behaviors of Al-Mg Foams

Hao Yu1, Xudong Yang2(), Weiting Li3, Xudong Rong1, Siyuan Guo1, Lishi Ma1, Lizhuang Yang1, Junwei Sha1(), Naiqin Zhao1,4()   

  1. 1Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin, 300350, China
    2Sino-European Institute of Aviation Engineering, Civil Aviation University of China, Tianjin, 300300, China
    3School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
    4Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, Tianjin, 300350, China

Abstract:

As widely used protective materials, the application of Al foams is still limited by their low intrinsic mechanical properties caused by the brittleness of struts. The introduction of Mg is recently demonstrated effective to improve the mechanical performance of Al foams; however, the mechanism of Mg modification is still not clear. In this work, Al-Mg foams are developed through a powder metallurgy process with excellent compression performance and high energy absorption capacity. The effects of Mg modification on the cell structure, toughness, and deformation behavior are investigated systematically. As a result, the small cell size of ~ 1.8 mm and the high sphericity of 0.92 are achieved with 5% of Mg addition, delivering high compression stress of 8.5 ± 0.43 MPa and energy absorption capacity of 6.9 ± 0.36 MJ/m3, simultaneously. The synergistic mechanism for the improved mechanical performance is also demonstrated to be the combination of stress transfer and plastic deformation behavior of cells. The results provide a new strategy to develop high-performance foam materials by improving toughness and further promote the practical application.

Key words: Powder metallurgy, Aluminum foam, Al-Mg alloy, Plastic deformation, Cell structure