Experimental and Numerical Investigations of the Plastic Deformation during Multi-Pass Asymmetric and Symmetric Rolling of High-Strength Aluminum Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 1157-1162 ◽  
Author(s):  
Cun Qiang Ma ◽  
Long Gang Hou ◽  
Ji Shan Zhang ◽  
Lin Zhong Zhuang
Keyword(s):  
Plastic Deformation ◽  
Shear Strain ◽  
Strain Distribution ◽  
Effective Strain ◽  
High Strength ◽  
Equivalent Strain ◽  
Asymmetric Rolling ◽  
Element Simulation ◽  
Before And After ◽  
High Strength Aluminum Alloys

For understanding the distribution of plastic deformation induced by asymmetric rolling (ASR), multi-pass ASR and symmetric rolling (SR) experiments combined with the finite element simulation were used for high-strength aluminum alloy in the present study. The influence of reduction per-pass on the shear / effective strain distributions were studied via different ASR processes. By measuring the shear angle (θ, the angle between the reference mark before and after rolling) of rolled sheets, redundant shear strain and equivalent strain were calculated. It is shown that with equal total thickness reduction for ASR and SR, ASR can induce much more shear deformation through the thickness. By calculating the evolution of redundant shear strain and total equivalent strain for different ASR routines, it indicates that small pass reduction could be much favorable to the strain accumulation than that of the large pass reduction under a same total reduction in ASR process. Also, the influence of shear stress on the strain distribution and the through-thickness strain distribution were studied and evaluated with FEM analyses.

Finite Element Modeling of Shear Strain in Rolling with Velocity Asymmetry in Multi-Roll Calibers

2014 ◽  
Vol 622-623 ◽  
pp. 912-918 ◽  
Author(s):  
Alexander Pesin ◽  
Mikhail Chukin ◽  
Alexey Korchunov ◽  
D.O. Pustovoytov
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shear Strain ◽  
High Pressure Torsion ◽  
Continuous Process ◽  
High Strength ◽  
Rolling Process ◽  
Asymmetric Rolling ◽  
Compression Scheme ◽  
Uniform Compression

Severe plastic deformation is now recognized the most efficient way of producing ultrafine grained metals and alloys. At the present time a lot of severe plastic deformation methods have been proposed and developed. They differ in the deformation schemes. Unlike such severe plastic deformation methods as high pressure torsion and equal-channel angular pressing, rolling with the velocity asymmetry is a continuous process. It helps to solve the problem of the limited length of manufactured bars with semi ultrafine structure. Rolling process with roll velocity asymmetry generates high shear strain necessary for obtaining ultrafine structures of the processed material. A new process of asymmetric rolling of profiles in multi-roll passes has been developed. This process can be used for production of high-strength profiles such as circles, hexagons, wire rods, etc. Compression of the bar in multi-roll passes can be done not only from two, as usual, but from three or four sides. In case of a multi-crimped bar, a uniform compression scheme with large hydrostatic pressure is created in the deformation zone. It enhances the ductility of the material and allows increasing the strain intensity. Simulation in DEFORM 3DTM proved that the process of asymmetric rolling in multi-roll calibers allows to obtain higher values of shear strain and strain effective.

Effects of Inner Corner Angle on Strain Distribution of ECAPed Aluminum Alloy

2013 ◽  
Vol 743 ◽  
pp. 231-234
Author(s):  
Xi Liang Chen ◽  
Qing Nan Shi
Keyword(s):  
Strain Distribution ◽  
Deformation Process ◽  
Effective Strain ◽  
High Strength ◽  
Deformation Method ◽  
Corner Angle ◽  
Angular Pressing ◽  
Ecap Process ◽  
Ultrafine Grained ◽  
Ultrafine Grained Materials

Ultrafine-grained materials have excellent mechanical properties, which include the high strength and toughness. Equal channel angular pressing (ECAP) is one kind of severe plastic deformation method to make ultrafine-grained metals. The ECAP processes are simulated by finite element method (FEM) in this work. The effects of inner corner angle on strain distribution during the deformation process are numerically analyzed. The evolutions of effective strain on three points of different deformation are compared. The results show that the deformation becomes severe on each point when the inner corner angle is less than 90o, which is different from the situation when the inner corner angle is equal to or greater than 90o. The results are useful for improving the ECAP process to make the structure of metals homogenous.

Effect of Extrusion Size on Forming Process in Equal Channel Angular Pressing

2013 ◽  
Vol 275-277 ◽  
pp. 2171-2175
Author(s):  
Xiao Lian Zhao ◽  
Ning Ning Zhao ◽  
Na Chen
Keyword(s):  
Plastic Deformation ◽  
Equivalent Stress ◽  
Equivalent Strain ◽  
Distribution Law ◽  
Forming Process ◽  
Angular Pressing ◽  
Element Simulation ◽  
Ultrafine Grained ◽  
Distribution Uniformity ◽  
Ultrafine Grained Materials

In order to meet the industrial demands for large-sized bulk ultrafine-grained materials, which were prepared by severe plastic deformation, the law curves of equivalent strain, equivalent stress and load of different-sized extrusions had been gotten by the finite element simulation of ECAP. The extrusion size has little effect on the values and distribution law of equivalent strain as well as the values of equivalent stress. With the increase of extrusion size, the distribution uniformity of equivalent stress decreases, and the extrusion load increases. Although the ECAP of the large-sized extrusions improve the requirements of mold and equipment, the chunk of evenly ultrafine-grained materials can be obtained by multiple passes.

FE Analysis of the Applicability of the Shear-Compression Testing to the Modeling of the Asymmetric Rolling Process

2016 ◽  
Vol 870 ◽  
pp. 226-233 ◽  
Author(s):  
Alexander M. Pesin ◽  
D.O. Pustovoytov
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shear Strain ◽  
Physical Simulation ◽  
Compressive Strain ◽  
Compression Testing ◽  
Ultrafine Grain ◽  
Asymmetric Rolling ◽  
Sheet Rolling ◽  
Material Production

The mechanism of a severe plastic deformation during asymmetric rolling comes from its large equivalent strain, which is composed of a compressive strain and additional shear strain. Physical simulation of shear strain, which is similar to that occurring in asymmetric rolling processes, is very important for design of technology of ultrafine grain material production. Shear testing is complicated because a state of large shear is not easily achievable in most specimen geometries. Application of the shear-compression testing and specimen geometry to physical simulation of asymmetric rolling is discussed in the paper. The results of the numerical simulation and comparison of the stress-strain state during shear-compression testing and asymmetric sheet rolling are presented. The results of the investigation can be used to optimize the physical simulation of asymmetric rolling processes and for the design of the technology for ultrafine grain material production by means of a severe plastic deformation.

Study of Forging Forming of 7075 Aluminum Alloy Bicycle Pedal

2012 ◽  
Vol 579 ◽  
pp. 101-108 ◽  
Author(s):  
Dyi Cheng Chen ◽  
Fung Ling Nian ◽  
Jiun Ru Shiu ◽  
Wen Hsuan Ku
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Effective Strain ◽  
High Strength ◽  
Mold Temperature ◽  
Grain Structure ◽  
7075 Aluminum Alloy ◽  
Rigid Plastic ◽  
Plastic Deformation Behavior

Forging is simple and inexpensive in mass production. Metallic materials are processed through plastic deformation. This not only changes the appearance but also changes the internal organization of materials that improve mechanical properties. However, regarding manufacturing of plastic products, many processing factors must be controlled to obtain the required plastic strain and desired tolerance values. In this paper, we employed rigid-plastic finite element (FE) DEFORMTM software to investigate the plastic deformation behavior of an aluminum alloy (A7075) workpiece as it used to forge bicycle pedals. First we use Solid works 2010 3D graphics software to design the bicycle pedal of the mold and appearance, moreover import finite element (FE) DEFORMTM 3D software for analysis. The paper used rigid-plastic model analytical methods, and assuming mode to be rigid body. A series of simulation analyses in which the variables depend on different temperatures of the forging billet, round radius size of ram, punch speed, and mold temperature were revealed to confirm the predicted aluminum grain structure, effective stress, effective strain, and die radial load distribution for forging a bicycle pedal. The analysis results can provide references for forming bicycle pedal molds. Finally, this study identified the finite element results for high-strength design suitability of a 7075 aluminum alloy bicycle pedal.

Through-Thickness Shear Strain in Silicon Steel under Asymmetric Rolling

2011 ◽  
Vol 702-703 ◽  
pp. 762-765
Author(s):  
H.P. Yang ◽  
Yu Hui Sha ◽  
Fang Zhang ◽  
Wei Pei ◽  
Liang Zuo
Keyword(s):  
Shear Strain ◽  
Strain Distribution ◽  
Sheet Thickness ◽  
Silicon Steel ◽  
Strain Variation ◽  
Asymmetric Rolling ◽  
Roll Pressure ◽  
Cold Rolled ◽  
Thickness Shear ◽  
Differential Speed

Through-thickness shear strain variation with speed/radius/friction ratio in cold rolled silicon steel under different asymmetric rolling modes was analyzed by finite element method (FEM). Cold rolling textures were also investigated quantitatively to correlate with the calculated shear strain. With increasing speed/radius/friction ratio, shear strain distribution under differential-speed and differential-radius rolling exhibits similar characteristic in contrast to differential-friction rolling. Unidirectional shear strain develops through sheet thickness when asymmetric speed and radius ratio exceeds 1.125, whereas it does not appear even at friction ratio of 1.5. Shear strain distribution dependent on asymmetric rolling modes can be well understood by forward and backward slip zones as well as roll pressure as a function of speed/radius/friction ratio.

scholarly journals Novel Process Combined Extrusion And Severe Plastic Deformation For Plate Component With Rib-Web Structure of Magnesium Alloys

2021 ◽  
Author(s):  
Nanyang Zhu ◽  
Chaoyang Sun ◽  
Lingyun Qian ◽  
Mingjia Wang ◽  
Xintong Li
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Magnesium Alloys ◽  
Strain Distribution ◽  
High Performance ◽  
Effective Strain ◽  
Shear Plane ◽  
Longitudinal Section ◽  
Fe Model ◽  
Web Structure

Abstract Plates with rib-web structure of magnesium alloys can hardly fabricated through conventional method. In this work, the variable circular channel angular extrusion (VCCAE) combined extrusion and severe plastic deformation is proposed, in which billet undergoes severe deformation at several variable circular angular channel. The FE model for VCCAE of scaling plate with ribs is established and the experimental set up is designed. The feasibility of the novel process and the accuracy of the FE model are validated by the simulations and experiments. Stress state and the effective strain distribution in longitudinal section and cross section are analyzed. The results show that stress and strain distribution in longitudinal section is extremely inhomogeneous, and obvious stress concentration at the shear plane is founded. The microstructure in angular region is more uniform and finer, which validate that the severe shear deformation induced by the angular channel in the VCCAE process could promote the deformation uniformity and grain refinement. The results of numerical simulation and experiments demonstrate that the VCCAE process proposed in this paper is feasible and it has great potential to manufacture high-performance plate with ribs.

Experimental Investigations of the Al 6082 Alloy Subjected to Equal-Channel Angular Pressing

2005 ◽  
Vol 473-474 ◽  
pp. 129-134
Author(s):  
György Krállics ◽  
Dmitry Malgyn ◽  
Arpad Fodor
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Relative Size ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Experimental Investigations ◽  
End Effects ◽  
Fine Grained ◽  
Angular Pressing ◽  
Element Simulation

The interest in bulk nanostructured materials (NSM), processed by methods of severe plastic deformation (SPD), is justified by their unique physical and mechanical properties. Equalchannel angular pressing (ECAP) is one of the methods of severe plastic deformation (SPD) that produces ultra fine-grained material. Due to the cyclic nature of the process, it is difficult to produce specimens with a high length to diameter ratio. Ratios of 6-7 have been reported in the literature to date. Longer specimens, however, are useful since the homogenous part is larger and the relative size of end effects is smaller. A new method was developed to obtain length to diameter ratios as high as 8-10. This new technique was developed using the multi-pass finite element simulation. The as-received alloy used in this study was the 6082 commercial Al-Mg-Si alloy. High strength and high ductility phenomenon that was found recently in materials after SPD were reached with the route C. The induced anisotropy of specimens after ECAP was monitored.

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