Grain refinement and superplastic behaviour of a modified 6061 aluminium alloy

Abstract

The superplastic properties and microstructure evolution of a 0 . 15%Zr and 0 . 7%Cu modi ed 6061 aluminium alloy were examined in tension at temperatures ranging from 475 to 600°C and strain rates ranging from 7610 2 6 to 2 . 8610 2 2 s 2 1 . The re ned microstructure with an average grain size of about 11 mm was produced in thin sheets by a commercially viable thermomechanical process. It was shown that the modi ed 6061 alloy exhibits a moderate superplastic elongation of 580% in the entirely solid state at 570°C and e .~2 . 8610 2 4 s 2 1 . Superior superplastic properties (elongation to failure of 1300% with a corresponding strain rate sensitivity coef cient m of about 0 . 65) were found at the same strain rate and a temperature of 590°C, which is higher than the incipient melting point of the 6061 alloy (~575°C). The microstructural evolution during superplastic deformation of the 6061 alloy has been studied quantitatively. The presence of a slight amount of liquid phase greatly promotes the superplastic properties of the 6061 alloy, reducing the cavitation level.MST/5315

Comparative study of hot-processing maps for 6061 aluminium alloy constructed from power constitutive equation and hyperbolic sine constitutive equation

“…35 Figures 5 and 6 show that the peak η of 6061 aluminium alloy is not >0·42. Furthermore, Kaibyshev et al studied high temperature deformation behaviour of 6061 aluminium alloy and concluded that superplastic deformation occurred at higher deformation temperature than 773 K. 1,2,36,37 Therefore, the superplastic deformation may not appear in this study.…”

“…The power law, equation (1), and the exponential law, equation (2), are suitable for low and high stress, respectively. The hyperbolic sine law, equation (3), is a more general form suitable for stresses over a wide range.…”

“…Hence, there were many work focused upon combination hot processing parameters and microstructure evolution during hot deformation of aluminium alloy, such as dynamic recovery, dynamic recrystallisation and superplastic forming. [1][2][3][4] It is generally accepted that the hot-processing map based of dynamic material modelling (DMM) is an effective tool for optimising hot-processing parameters in terms of the various microstructural mechanisms operating at different deformation conditions. The hot-processing map, which can be divided into a safe domain and an unsafe domain, is a superimposition of a power-dissipation map and an instability map.…”

Continuous repair of groove damages using solid-state friction rolling additive manufacturing method

“…The results show that the closer the material is to the tool head, the higher the temperature and temperature gradient. The maximum temperature of the material 2 mm away from the tool head reaches 433°C, which is 75% of the melting point (575°C) of 6061 aluminium alloy [26]. The maximum temperature is close to the maximum temperature reached by the materials in FSW at a distance of 1.50 mm from the shoulder (450°C) [27].…”

Effect of P-MIG and CMT on microstructure and properties of 6082-T6 joints

“…6082-T6 aluminium alloy is a medium-strength heattreatable Al-Mg-Si alloy with good forging properties, weldability, corrosion resistance, and machining characteristics, which is widely used in the field of highspeed trains and urban rail vehicles [1][2][3][4]. Welding is the main manufacturing method of aluminium alloy connection, and the performance of the joint is closely related to the welding process and composition of the welding materials.…”