Application of CGP-cross route process for microstructure refinement and mechanical properties improvement in steel sheets

Khodabakhshi, F.; Abbaszadeh, M.; Eskandari, H.; Mohebpour, Saeed Reza

doi:10.1016/j.jmapro.2013.08.001

Cited by 40 publications

(23 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By adding the pass numbers and increment of the dislocations density, misorientation angle is increased; hence, they change gradually to the high angle grain boundaries. [49][50][51] As claimed, there is an approach to estimate dislocations density of the material based on the lattice microstrain and crystallite size according to equation (3). 52 In this equation, r and b denote the total dislocations density and the Burgers vector, respectively.…”

Section: Resultsmentioning

confidence: 99%

Equal channel angular pressing of wire-formed Al6063 by PU rubber-assisted procedure

Ebrahimi

Attarilar

Özkavak

et al. 2021

The Journal of Strain Analysis for Engineering Design

View full text Add to dashboard Cite

Expanding suitable severe plastic deformation processes seems essential to design lightweight wire-formed materials for emerging demands. In this regard, 6063 aluminum alloy in the form of wire was processed successfully by polyurethane rubber assisted-equal channel angular pressing up to 16 passes by route BC. It was found that significant improvement of hardness and strength is achieved at the initial passes due to the increment of material’s dislocations density which leads to the crystallite size decrease and lattice microstrain increase. Also, subsequent passes improve the mechanical properties with a gentle rate due to the saturation of dislocation strengthening. The fractography analysis indicated that the ductile fracture mode of the annealed aluminum decreases by imposing the ECAP process. It is related to the formation of cleavage and rive patterns and the reduction in the number and size of the dimples compared to the initial condition. Eventually, X-ray diffraction findings showed that by adding pass numbers, the isotropy degree of the aluminum sample enhances because of the lowest diffraction scattering.

show abstract

Section: Resultsmentioning

confidence: 99%

Equal channel angular pressing of wire-formed Al6063 by PU rubber-assisted procedure

Ebrahimi

Attarilar

Özkavak

et al. 2021

The Journal of Strain Analysis for Engineering Design

View full text Add to dashboard Cite

show abstract

“…8 CGP technique was first developed by Shin et al 9 in 2002 and many studies have been conducted on it. 6,7,[10][11][12][13][14][15][16][17] The principle of the CGP process is to create severe plastic deformation based on repetitive pressing of the sheet under the two sets of symmetrically grooved and flat dies. 18 A single pass of the CGP process includes four steps, the sequence of which is illustrated in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Effect of the uncertainty of multi-cut contour method and friction coefficient on residual stresses of constrained groove pressing process

Nazari

Honarpisheh

Zhao

2020

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

Constrained groove pressing (CGP) process is a severe plastic deformation (SPD) method that can create ultrafine-grained microstructure in the sheet metals. In this study, residual stresses of the CGP process and the effect of the friction coefficient on the residual stresses were investigated. The residual stresses were measured in two directions using a multi-cut contour method and a mathematical-finite element model was developed to estimate the uncertainty of results of the multi-cut contour method. In order to study the effect of the friction coefficient on the residual stresses, a 3D finite element model was employed and the results of it were validated with the experimental results of the CGP process. According to the results, residual stresses in the first pass of CGP are compressive on the surface and gradually change to tension at the center of the thickness. Investigation of the effect of the first cut on the residual stresses and uncertainty of the second cutting plane showed that the effect of the first cut is only confined to regions near the intersection of the two cuts. Distancing from the intersection of two cuts causes the effect of the first cut to be ineffective on the second cut. Also, evaluation of the effect of friction coefficient on the residual stress illustrated that friction has a direct relationship with the residual stresses.

show abstract

“…2 The yield strength, hardness, fatigue strength, plasticity, diffusivity, and corrosion resistance of the UFG materials are improved by grain refinement, while their elongation and ductility are decreased. 1,[3][4][5] The equal channel angular pressing (ECAP) is considered to be one of the most applicable methods among SPD processes, developed by Segal et al 6 In this process, the billet is extruded through the ECAP die (two equal channels) and undergoes ultra-deformation, resulting in locking dislocations and grain refinement of the billet. Recently, using UFG materials in the automobile, military, medical, and aerospace industries has been considered.…”

Section: Introductionmentioning

confidence: 99%

The surface integrity of ultra-fine grain steel, Electrical discharge machined using Iso-pulse and resistance–capacitance-type generator

Mahdieh

2020

Proceedings of the Institution of Mechanical Engineers, Part L:

View full text Add to dashboard Cite

Ultra-fine grained materials with high strength and low weight are eventually considered to be used in industries. To produce ultra-fine grained materials, equal channel angular pressing is a functional method, imposing severe plastic deformation on the workpiece. Electrical discharge machining is an indispensable process in manufacturing industrial parts with high accuracy and precision. However, electrical discharge machining has thermo-physical consequences, damaging the surface layers of the workpiece. On the other hand, the ultra-fine grained materials are thermodynamically unstable and tend to microstructural evolution. Thus, electrical discharge machining process affects the ultra-fine grained materials more than coarse grain materials. In this study, the effects of electrical discharge machining on the ultra-fine grained steel were investigated and the undesirable influences of the electrical discharge machining were diminished by adjusting the electrical discharge machining parameters. The ultra-fine grained steel samples were electrical discharge machined in two methods including Iso-pulse (roughing mode and finishing mode) and with resistance–capacitance-type generator. The surface integrity parameters, including thickness and microstructure of the recast layer and heat-affected zone, the cracks density and hardness, which for all three types of samples, were investigated by scanning electron microscopy, optical microscopy, X-ray diffraction technique, and micro-hardness tester. The results show that electrical discharge machining with resistance–capacitance-type generator has the minimum effects on the surface integrity of the ultra-fine grained samples because of the different material removal mechanism of resistance–capacitance-type electrical discharge machining.

show abstract

Application of CGP-cross route process for microstructure refinement and mechanical properties improvement in steel sheets

Cited by 40 publications

References 32 publications

Equal channel angular pressing of wire-formed Al6063 by PU rubber-assisted procedure

Equal channel angular pressing of wire-formed Al6063 by PU rubber-assisted procedure

Effect of the uncertainty of multi-cut contour method and friction coefficient on residual stresses of constrained groove pressing process

The surface integrity of ultra-fine grain steel, Electrical discharge machined using Iso-pulse and resistance–capacitance-type generator

Contact Info

Product

Resources

About