Acoustic softening and residual hardening in aluminum: Modeling and experiments

Yao, Zhehe; Kim, Gap Yong; Wang, Zhihua; Faidley, Le Ann; Zou, Qingze; Mei, Deqing; Chen, Zichen

doi:10.1016/j.ijplas.2012.06.003

Cited by 247 publications

(84 citation statements)

References 54 publications

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“…For this purpose, the change of activation energy (DF) as a key factor during ultrasonic excitation appears in the ratio of flow stress reduction versus mechanical threshold (ŝ). Referring to experimental observations reported by literatures (Ref [18][19][20][21]26), the decrease in flow stress is proportional to the vibration amplitude (or square root of ultrasonic energy density). Hence, the difference in the ratio of flow shear stress (s) to the internal variable (ŝ) between both conditions under ultrasonic vibration (index ''U'') and without vibration (index ''0'') is expressed as…”

Section: Constitutive Model For Mechanical Behaviormentioning

confidence: 62%

“…Therefore, the mechanical behavior of metal under HUV excitation needs to be described by suitable constitutive equation based on microstructural evolution during process (Ref 4). The general framework of crystal plasticity and dislocation density evolution that presented later by literatures (Ref [26][27][28][29][30][31][32] was used for modeling of the stress-strain relationship of pure aluminum in ultrasonic-assisted compression test, which is discussed in the following briefly.…”

Section: Constitutive Model For Mechanical Behaviormentioning

confidence: 99%

See 1 more Smart Citation

Effect of Ultrasonic Vibration on Compression Behavior and Microstructural Characteristics of Commercially Pure Aluminum

Bagherzadeh

Abrinia

2015

J. of Materi Eng and Perform

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The principle objective of this research is to investigate the modeling of compression behavior and microstructural evolution of pure aluminum in the ultrasonic-assisted compression test. A dislocation density-based constitutive model was developed based on the existing frameworks and calibrated using experimental data to predict the stress-strain response of pure aluminum during UAC tests. An experimental set-up was designed to work at resonance condition with frequency of around 20 kHz and variant longitudinal vibration amplitudes at the range of 0$20 lm. The verified model and experimental samples were used for parameter studies and the study of grain formation of aluminum after conventional and ultrasonic upsetting. Results showed that the developed constitutive model was able to predict compression behavior of aluminum suitably. An increase in the flow stress drop, residual flow stress, and dislocation density occurred when the applied vibration intensity was raised. In addition, it was observed that the more homogenous microstructure with nearly equiaxed grains and also the higher microhardness values can be achieved when ultrasonic vibration is imposed on samples during compression test.

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Section: Constitutive Model For Mechanical Behaviormentioning

confidence: 62%

Section: Constitutive Model For Mechanical Behaviormentioning

confidence: 99%

Effect of Ultrasonic Vibration on Compression Behavior and Microstructural Characteristics of Commercially Pure Aluminum

Bagherzadeh

Abrinia

2015

J. of Materi Eng and Perform

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show abstract

“…Enhancement of dipole annihilation and faster traveling of the dislocations are two probable roles of dislocations in ultrasonic softening which have been proposed by the researchers [27,[29][30][31]36,38].…”

Section: Discussionmentioning

confidence: 98%

“…Recently, a few studies have focused on developing models for acoustic plasticity based on the crystal plasticity theory [38][39][40][41][42]. These models help to understand the underlying mechanisms of ultrasonic softening.…”

Section: Introductionmentioning

confidence: 99%

Effect of grain size on ultrasonic softening of pure aluminum

2015

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“…Nonetheless, there is still a problem, since material deformation due to high-frequency ultrasonic treatment can lead to a variety of contradicting phenomena, which are (i) acoustic softening [3], (ii) acoustic hardening [4], (iii) acoustic heating [5], etc. Researchers suggest various interpretations of the strong influence caused by this small effect.…”

Section: Introductionmentioning

confidence: 99%