Enhancing strength and ductility synergy through heterogeneous structure design in nanoscale Al2O3 particulate reinforced Al composites. (15th March 2019)

• Record Type: Journal Article
• Authors: Zan, Y.N.; Zhou, Y.T.; Liu, Z.Y.; Ma, G.N.; Wang, D.; Wang, Q.Z.; Wang, W.G.; Xiao, B.L.; Ma, Z.Y.
• Is Part Of: Materials & design. Volume 166(2019)
• Publication Date: 2019-03-15
• Subjects: Metal matrix composites -- Nanoparticles -- High energy ball milling -- Ultrafine grain -- Ductility; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2019.107629
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Nanoparticle reinforced aluminum matrix composites fabricated by a high energy ball milling method showed significantly improved strength, however, their ductility was relative lower. This study proposed for the first time a heterogeneous structure strategy toward good strength and ductility synergy for Al matrix composites. Nanoscale Al2 O3 particulate reinforced pure Al composites were fabricated as model materials. Three ball milling procedures were conducted to construct uniform ultrafine grain, random bi-modal grain, and heterogeneous lamella grain structures. It was shown that all composites exhibited significantly improved tensile strength. The heterogeneous lamella structure provided the composites with increased tensile strength and ductility compared to the uniform or the random bi-modal grain structure. Compared to ball milled pure Al, the heterogeneous structure composite had 160% and 121% increases in yield stress and ultimate tensile stress, respectively. Meanwhile, its elongation was as high as 8%. The results were rationalized through back stress theory. Geometrically necessary dislocations were believed to be the main reason for the good ductility without strength sacrifice. Graphical abstract: Unlabelled Image Highlights: A heterogeneous lamella structure was constructed in nanoscale alumina reinforced aluminum matrix composites for the first time. The heterogeneous lamella structure of the composite provided high elongation without sacrificing strength. A strategy toward strength and ductility synergy for ultrafine grain composites was proposed.