Leveraging transient mechanical effects during stress relaxation for ductility improvement in aluminium AA 8011 alloy

Prasad, Kali; Hariharan, K.; Jain, Jayant

doi:10.1016/j.jmatprotec.2017.11.053

Cited by 23 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been shown that stress relaxation during plastic deformation delays the onset of fracture. This has been experimentally verified in many materials [19][20][21][22][23][24]. The improvement is primarily | https://mc03.manuscriptcentral.com/friction attributed to the combined effect of dislocation annihilation and homogenization of internal stress [25][26][27].…”

Section: Introductionmentioning

confidence: 71%

See 1 more Smart Citation

Does friction contribute to formability improvement using servo press?

et al. 2023

Self Cite

View full text Add to dashboard Cite

Servo press forming machines are advanced forming systems that are capable of imparting interrupted punch motion, resulting in enhanced room temperature formability. The exact mechanism of the formability improvement is not yet established. The contribution of interrupted motion in the ductility improvement has been studied through stress relaxation phenomena in uniaxial tensile (UT) tests. However, the reason for improved formability observed when employing servo press is complicated due to the additional contribution from frictional effects. In the present work, an attempt is made to decouple the friction effect on formability improvement numerically. The improved formability is studied using a hole expansion test (HET). The limit of forming during hole expansion is modeled using the Hosford-Coulomb (HC) damage criteria, which is implemented as a user subroutine in a commercial explicit finite element (FE) software. Only the contribution of stress relaxation is accounted for in the evolution of the damage variable during interrupted loading. Therefore, the difference between simulation and experimental hole expansion ratio (HER) can be used to decouple the friction effect from the overall formability improvement during hole expansion. The improvement in HER due to stress relaxation and friction effect is different. The study showed that the model effectively captures the hole expansion deformation process in both monotonic and interrupted loading conditions. Compared to stress relaxation, friction effect played a major role during interrupted HET.

show abstract

Section: Introductionmentioning

confidence: 71%

“…The observed trend is in line with Refs. [19][20][21] on ductility improvement due to stress relaxation.…”

Section: Fracture Tests and Hc Model Calibrationmentioning

confidence: 99%

Does friction contribute to formability improvement using servo press?

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recently, a large number of publications have appeared on the relaxation phenomena of structure and deformation at the moment of stopping the test without current [ 31 , 32 ] or transmission of single-current pulses observed on tensile curves [ 33 ]. In almost all cases, relaxation contributed to the improvement of plasticity.…”

Section: Deformation Behaviormentioning

confidence: 99%

A Pulsed Current Application to the Deformation Processing of Materials

Stolyarov,

Misochenko

2023

Materials

View full text Add to dashboard Cite

A review of studies on the electroplastic effect on the deformation process in various conductive materials and alloys for the last decade has been carried out. Aspects, such as the mode and regimes of electric current, the practical methods of its introduction into materials with different deformation schemes, features of deformation behavior accompanied by a pulsed current of different materials, structural changes caused by the combined action of deformation and current, the influence of structural features on the electroplastic effect, changes in the physical, mechanical, and technological properties of materials subjected to plastic deformation under current, possible mechanisms and methods of physical and computer modeling of the electroplastic effect, and potential and practical applications of the electroplastic effect are considered. The growing research interest in the manifestation of the electroplastic effect in such new modern materials as shape-memory alloys and ultrafine-grained and nanostructured alloys is shown. Various methods of modeling the mechanisms of electroplasticity, especially at the microlevel, are becoming the most realistic approach for the prediction of the deformation behavior and physical and mechanical properties of various materials. Original examples of the practical application of electropulse methods in the processes of drawing, microstamping, and others are given.

show abstract

“…Moreover, the slip motion of screw dislocation produces polygon lead to the dislocation in the entanglement reassembled. And the diffusion of internal atom is gradually enhanced, which causes deformed structure transform to a lower energy state [19,20]. So, the hardness value decreases.…”

Section: Optical Microstructurementioning

confidence: 99%

Effects of annealing treatment on mechanical properties of 8011 aluminum alloy after cryogenic rolling

Cui

Chen

Li³

et al. 2019

Metall. Res. Technol.

View full text Add to dashboard Cite

In order to improve mechanical properties of roll cast 8011 aluminum alloy (AA 8011) by grain strengthening, and expand its application field, the effect of different annealing treating processes on mechanical properties and microstructures of cryogenic rolled AA 8011 was investigated. The roll cast AA 8011 was cryogenic rolled for six passes and then annealed. The annealing treatment was adopted at 100–300 °C for 1 h, and then the annealing treatment was adopted at 220 °C for 10–80 min. The microstructures of AA 8011 under roll cast and cryogenic rolled states were studied by using OM. The grain size was calculated by the Image-pro-plus 5.0. The microstructures of AA 8011 under annealing states were observed by using TEM and energy dispersive spectrum analysis. The results show that the second phase Al8Fe2Si appears in the cryogenic rolled AA 8011 after annealing treatment. When the dislocation moves in the grain, the dislocation plays a pinning role, which is conducive to grain refinement. The optical annealing treatment was treated at 220 °C for 40 min with optimal thermal stability. The ideal grain size is 1 μm, hardness is 65 HV, and tensile strength is 202 MPa. It is about 1.5 times of the roll cast AA 8011.

show abstract

Leveraging transient mechanical effects during stress relaxation for ductility improvement in aluminium AA 8011 alloy

Cited by 23 publications

References 20 publications

Does friction contribute to formability improvement using servo press?

Does friction contribute to formability improvement using servo press?

A Pulsed Current Application to the Deformation Processing of Materials

Effects of annealing treatment on mechanical properties of 8011 aluminum alloy after cryogenic rolling

Contact Info

Product

Resources

About