A study of thermomechanical behaviour and grain size evolution of AA7050 under hot forging conditions

Li, Weishu; Liu, Yaoqiong; Jiang, Shuai; Luan, Qinmeng; Li, Yibo; Gu, Bin; Shi, Zhusheng

doi:10.1016/j.ijlmm.2018.10.002

Cited by 10 publications

(2 citation statements)

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“…These thermal treatments often induce additional thermal stress into the samples and could also lead to severe oxidation under nonvacuum conditions [11,12]. Other than thermal processing, severe plastic deformation (SPD) technique, spark plasma sintering (SPS), Laser Engraving, and surface mechanical treatment are some microstructure modification methods, each tailored to specific needs and applications [13][14][15][16]. For example, Li et al [13] employed the SPD technique to obtain refined grains for NiTi-based alloys.…”

Section: Introductionmentioning

confidence: 99%

Room temperature control of grain orientation via directionally modulated current pulses

Rahman,

Oh,

Waryoba

et al. 2023

Mater. Res. Express

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Traditional approaches to control the microstructure of materials, such as annealing, require high temperature treatment for long periods of time. In this study, we present a room temperature microstructure manipulation method by using the mechanical momentum of electrical current pulses. In particular, a short burst of high-density current pulses with low duty cycle is applied to an annealed FeCrAl alloy, and the corresponding response of microstructure is captured by using Electron Backscattered Diffraction (EBSD) analysis. We show evidence of controllable changes in grain orientation at specimen temperature below 28 C. To demonstrate such microstructural control, we apply the current pulses in two perpendicular directions and observe the corresponding grain rotation. Up to 18 of grain rotation was observed, which could be reversed by varying the electropulsing direction. Detailed analysis at the grain level reveals that electropulsing in a specific direction induces clockwise rotation from their pristine state, while subsequent cross-perpendicular electropulsing results in an anticlockwise rotation. In addition, our proposed room temperature processing yields notable grain refinement, while the average misorientation and density of low-angle grain boundaries (LAGBs) remain unaltered. The findings of this study highlight the potentials of 'convective diffusion' in electrical current based materials processing science towards microstructural control at room temperature.

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Section: Introductionmentioning

confidence: 99%

Room temperature control of grain orientation via directionally modulated current pulses

Rahman,

Oh,

Waryoba

et al. 2023

Mater. Res. Express

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“…AA7050 is widely used in the field of aerospace engineering because of its high strength-todensity ratio and excellent mechanical properties. It has been reported that dynamic recrystallisation of the AA7050-T7451 occurred at a deformation temperature of 400 °C and strain rate of 0.05 s -1 and progressed further with increasing temperature and decreasing strain rate (Li et al, 2019). Thus, this alloy was selected as a suitable material for validating the model.…”

Section: Model Application and Validation For Aluminium Alloy Aa7050mentioning

confidence: 99%

A CDRX-based material model for hot deformation of aluminium alloys

Jiang

et al. 2020

International Journal of Plasticity

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During hot deformation, continuous dynamic recrystallisation (CDRX) is believed to occur, and even dominates microstructural evolution in many metallic materials with high stacking fault energy, such as aluminium alloys. A unique material model for hot deformation of aluminium alloys is proposed in this paper, based on consideration of two processes: (i) increase of dislocation density, induced by plastic deformation, leading to generation, rotation and migration of low angle grain boundaries (LABs) and their transformation into high angle grain boundaries (HABs); (ii) migration of HABs leading to annihilation of both LABs and HABs. At large strain, the above counteracting processes, guided by different mechanisms, lead to saturation of HABs fraction. The model is applied to hot deformation of AA5052 and AA7050 alloys under various temperatures and strain rates, and calculated flow stress, HABs fraction and grain size evolution for both alloys agree well with the corresponding experimental data. The capability of predicting saturation of HABs fraction and average subgrain misorientation angle of both alloys under large strains demonstrate the potential applicability of the model to a wide range of hot forming process conditions.

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