Superplasticity and Deformation Mechanism of LD10 Aluminium Alloy
The commercial hot-rolled bars of LD10 alloy (grain size 25~75µm) are pretreated via proper recrystallization annealing (temperature 380°C, 420°C and 460°C) and solution annealing (temperature 500°C). The average elongation is increased from 158% to 270%, 223%, 219% and 233% respectively and the maximum elongation is 321% (500°C, 3.3×10-4s-1). The test results show that the alloy can present certain superplasticity owing to structural effect of dynamic recrystallization refining during superplastic deformation of coarse-grained LD10 alloy. Large and deep cavities form in grain boundaries and result in intergranular fracture after larger superplastic tensile deformation. And a large amount of metal filaments appear on grain surfaces. The formation of filaments is attributed to viscous flow of solid-liquid mixture in grain boundaries caused by grain-boundary sliding. The appearance of solid-liquid mixture makes grain-boundary sliding easier.
Z.Y. Zhong, H. Saka, T.H. Kim, E.A. Holm, Y.F. Han and X.S. Xie
H. Z. Guo et al., "Superplasticity and Deformation Mechanism of LD10 Aluminium Alloy", Materials Science Forum, Vols. 475-479, pp. 2941-2944, 2005