Investigations on the material property changes of ultrasonic-vibration assisted aluminum alloy upsetting

Hung, Jung-Chung; Lin, Chih-Chia

doi:10.1016/j.matdes.2012.07.021

Cited by 88 publications

(14 citation statements)

References 18 publications

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“…According to the dislocation mechanism, when the metal absorbs the acoustic energy and dislocation energy increases, which makes the sliding and multiplication of dislocations occur easily and further leads to a reduction of deformation resistance. As a result, the larger of the vibration amplitude is applied, the more drop of the yield strength [29,31].…”

Section: Resultsmentioning

confidence: 99%

Acoustic softening and stress superposition in ultrasonic vibration assisted uniaxial tension of copper foil: Experiments and modeling

et al. 2016

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Ultrasonic vibration is widely utilized in manufacturing processes mainly because acoustic field could significantly affect the metal plasticity leading to stress reduction. However, viewpoints on the influence mechanism have not reached a consensus yet. In this paper, an ultrasonic vibration assisted uniaxial tension experiment with copper foils is carried out using a specially-developed device. The results show that the extent of stress reduction increases with the increase of the vibration amplitude. Acoustic softening and stress superposition are both considered in a developed model to describe the stress reduction due to ultrasonic excitation during metal forming process. Considering ultrasonic vibration provides the energy for dislocation sliding, acoustic softening is analyzed based on crystal plasticity theory considering ultrasonic intensity. Stress superposition, mostly induced by the additional periodic strain, is included by taking account of its proportional relationship with vibration amplitude. The calculation results from the numerical model show a good agreement with those from the experiment. These findings provide an instructive understanding of mechanism of stress reduction in ultrasonic vibration assisted metal deformation and is especially helpful for pro-actively designing ultrasonic vibration assisted metal forming processes.

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Section: Resultsmentioning

confidence: 99%

Acoustic softening and stress superposition in ultrasonic vibration assisted uniaxial tension of copper foil: Experiments and modeling

et al. 2016

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“…The investigation of Liu et al [ 26 ] indicated that the ultrasonic wave during the upsetting process leads to fabricating the UFG structure on the pure copper cone tips. Although multiple studies have shown a beneficial effect of the USV on the structure and mechanical properties [ 27 , 28 , 29 ], the detailed research concerning vibration impact on the material formability as well as grain refinement in the Al–Mg alloy system is limited. To date, we found only one publication related to the application of USV [ 30 ] in the Al–Mg alloy system and a few related to the Al–Mg–Si system [ 31 , 32 , 33 ].…”

Section: Introductionmentioning

confidence: 99%

Ultrasound Effect on the Microstructure and Hardness of AlMg3 Alloy under Upsetting

et al. 2021

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To date, numerous investigations have shown the beneficial effect of ultrasonic vibration-assisted forming technology due to its influence on the forming load, flow stress, friction condition reduction and the increase of the metal forming limit. Although the immediate occurring force and mean stress reduction are known phenomena, the underlying effects of ultrasonic-based material softening remain an object of current research. Therefore, in this article, we investigate the effect of upsetting with and without the ultrasonic vibrations (USV) on the evolution of the microstructure, stress relaxation and hardness of the AlMg3 aluminum alloy. To understand the process physics, after the UAC (ultrasonic assisted compression), the microstructures of the samples were analyzed by light and electron microscopy, including the orientation imaging via electron backscatter diffraction. According to the test result, it is found that ultrasonic vibration can reduce flow stress during the ultrasonic-assisted compression (UAC) process for the investigated aluminum–magnesium alloy due to the acoustic softening effect. By comparing the microstructures of samples compressed with and without simultaneous application of ultrasonic vibrations, the enhanced shear banding and grain rotation were found to be responsible for grain refinement enhancement. The coupled action of the ultrasonic vibrations and plastic deformation decreased the grains of AlMg3 alloy from ~270 μm to ~1.52 μm, which has resulted in a hardness enhancement of UAC processed sample to about 117 HV.

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“…al. concluded that the mechanisms of increased temperature and energy absorption of dislocation could affect the material property and cause a reduction in forming forces [ 37 ]. The regulations presented in these literatures are in accordance with those observed in our tests.…”

Section: Experimental Results and Analysismentioning

confidence: 99%

Effect of a Compound Energy Field with Temperature and Ultrasonic Vibration on the Material Properties and Bending Process of TC2 Titanium Alloy

Gao

Wang

Ling³

et al. 2021

Materials

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Due to the low formability and forming quality of titanium alloy, the forming process of a compound energy field (CEF) with temperature and ultrasonic vibration was proposed. Tensile tests were carried out to investigate the effect of the CEF on the true stress–strain curve, yield strength, elastic modulus, and other mechanical properties of the TC2 titanium alloy. Bending tests assisted by CEF were also performed to investigate the effect of different parameters of the CEF on bending force, spring-back, bending fillet radius, and microstructure of TC2 titanium. The results demonstrate that compared to the process under a single-temperature field, the CEF can reduce yield strength, elastic modulus, bending force, bending fillet, and the spring-back angle, which shows that the CEF can further increase the high-temperature softening effect of TC2 titanium. Furthermore, this effect becomes more remarkable when ultrasonic vibration energy increases. As a result, the formability of titanium alloy can be improved.

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Investigations on the material property changes of ultrasonic-vibration assisted aluminum alloy upsetting

Cited by 88 publications

References 18 publications

Acoustic softening and stress superposition in ultrasonic vibration assisted uniaxial tension of copper foil: Experiments and modeling

Acoustic softening and stress superposition in ultrasonic vibration assisted uniaxial tension of copper foil: Experiments and modeling

Ultrasound Effect on the Microstructure and Hardness of AlMg3 Alloy under Upsetting

Effect of a Compound Energy Field with Temperature and Ultrasonic Vibration on the Material Properties and Bending Process of TC2 Titanium Alloy

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