Microstructure and mechanical properties of high product of strength and elongation Al-Zn-Mg-Cu-Zr alloys fabricated by spray deposition. (15th April 2016)

• Record Type: Journal Article
• Authors: Liu, Bin; Lei, Qian; Xie, Liuqun; Wang, Mingpu; Li, Zhou
• Is Part Of: Materials & design. Volume 96(2016)
• Page Start: 217
• Page End: 223
• Publication Date: 2016-04-15
• Subjects: Spray deposition -- Microstructure -- Aluminum alloys -- Strength -- Ductility; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.02.011
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Large-scale Al-Zn-Mg-Cu-Zr alloys rods were fabricated by spray deposition. Microstructure observations reveal that equiaxed grains formed in the ingots, and the grain size in spray-deposited ingot was smaller than of the commercial product. High product of strength-elongation (11.9 GPa·%.) alloy was obtained through spray deposition and followed by hot extrusion and solution treatment. This resulted in a good combination of strength and elongation (Ultimate tensile strength: 684 MPa; Elongation: 17.4%). Hot extrusion improved the mechanical properties, while T6 treatment improved the tensile strength but decreased the elongation. The high-density nano-scale precipitates (η′ and Al3 Zr precipitates) caused the improved strength (723 MPa), but were detrimental to the specimens' ductility (11%). Intergranular fracture and transgranular fracture are main fracture mechanisms in extrusion state and T6 treatment samples, respectively. Brittle secondary-phase particles cracked during tension test process owing to their limited ductility. Graphical abstract: Highlights: Large-scale Al-Zn-Mg-Cu-Zr alloys were successfully fabricated by spray deposition. High product of strength-ductility alloy was developed. Intergranular fracture is the main fracture mechanism in extrusion state samples. Transgranular fracture is main fracture mechanism T6 treatment samples.