INFLUENCE OF BILLET SIZE ON THE DEFORMATION INHOMOGENEITY OF MATERIAL PROCESSED BY EQUAL CHANNEL ANGULAR PRESSING

2008 ◽  
Vol 22 (31n32) ◽  
pp. 6088-6093 ◽  
Author(s):  
TAO SUO ◽  
YULONG LI ◽  
FENG ZHAO
Keyword(s):  
Equal Channel Angular Pressing ◽  
Equivalent Plastic Strain ◽  
Finite Element Models ◽  
Plastic Strains ◽  
Angular Pressing ◽  
Ecap Process ◽  
Ultrafine Grained ◽  
Deformation Inhomogeneity ◽  
Different Diameters ◽  
Ultrafine Grained Microstructure

Equal channel angular pressing provides a convenient procedure for introducing an ultrafine grained microstructure into materials. In this paper, the deformation distribution of cylindrical billet with different diameters during equal channel angular pressing (ECAP) was simulated using 3D finite element models. The plastic strains in three perpendicular planes of the billet are predicted. And the influence of the friction between billet and channel on the equivalent plastic strain is also determined. The results show that the equivalent plastic strains are inhomogeneous in three directions and the inhomogeneity of the strain distribution inside ECAPed materials is slightly related to their diameters, which means larger scale UFG materials can be achieved via ECAP process.

Equal Channel Angular Pressing of Cu-Al Bimetallic Rod

2012 ◽  
Vol 706-709 ◽  
pp. 1811-1816 ◽  
Author(s):  
Núria Llorca-Isern ◽  
Ana Maria Escobar ◽  
Antoni Roca ◽  
Jose María Cabrera
Keyword(s):  
Equal Channel Angular Pressing ◽  
X Ray Diffraction ◽  
Angular Pressing ◽  
Refined Microstructure ◽  
Ultrafine Grained ◽  
Clad Metals ◽  
Grain Fragmentation ◽  
Different Diameters ◽  
Objective Being ◽  
Ultrafine Grained Microstructure

Coextrusion and corolling are the major processes to produce bimetallic rods, tubes and wires, the objective being to perform clad metals, bimetallic joints or seals. The aim of the present work is to produce bimetallic rods showing an ultrafine grained microstructure with enhanced properties. Bimetallic Cu-Al rods were deformed by equal channel angular pressing (ECAP) in order to study their microstructure. ECAP is an interesting process for producing bulk materials with refined microstructure and, consequently, changes in physical, chemical and mechanical properties can be observed. Higher shear strength and dimensional stability are among the advantages of this process. A comparative experimental study of pure commercial copper with cylindrical inner aluminium rods of different diameters processed by one-pass equal channel angular pressing has been carried out. The ECAP die used in this research was a 90º 2-channels intersecting angle. Electron backscattered (EBSD) and X-ray diffraction techniques were used for microstructure characterization (deformation, grain fragmentation and microstrain evaluation) at the interfaces and away from them. It was found that the microstructure in the ECAP deformed Cu-Al bimetallic rods was influenced by the dimensions of the aluminium inner rod. In fact, the microstructure appeared to be much more elongated and refined in the samples containing smaller diameter aluminium rods.

Structuration of Refractory Metals Tantalum and Niobium Using Modified Equal Channel Angular Pressing Technique

2019 ◽  
Vol 799 ◽  
pp. 103-108 ◽  
Author(s):  
Lembit Kommel ◽  
Babak Shahreza Omranpour ◽  
Valdek Mikli
Keyword(s):  
Equal Channel Angular Pressing ◽  
Coarse Grained ◽  
Uniaxial Tensile ◽  
Modified Technique ◽  
Uniaxial Tensile Strength ◽  
Large Samples ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Von Mises ◽  
Ultrafine Grained Microstructure

In the present work, we use a modified Equal Channel Angular Pressing technique for structure and properties change of Tantalum and Niobium at room temperature. The main advantage of this modified technique is the possibility to produce relatively large samples with ultrafine-grained microstructure in all volume of the workpiece by reduced deformation load up to 25% via friction decrease, and also to prevent the punch fracture under high compression stress during pressing. The various microstructures and properties were produced in metals by using different von Mises strain levels up to ƐvM = 13.8. The changes in microstructure were studied by using SEM and TEM techniques. The change of mechanical properties was measured by using various tension and hardness testing setups. We can conclude that during processing the ultrafine-grained microstructure in as-cast Nb and Ta was formed. The uniaxial tensile strength, Vickers hardness, and plasticity of Nb and Ta significantly increased as compared to coarse-grained counterparts. We believe that the relatively large workpieces of pure bulk Ta and Nb metals with improved microstructure and exploitation properties are suitable materials for the modern industry.

Extraordinary High Strain Rate Superplasticity of an Al-Mg-Sc-Zr Alloy Subjected to Equal Channel Angular Pressing

2012 ◽  
Vol 735 ◽  
pp. 295-300
Author(s):  
Elena Avtokratova ◽  
Oleg Sitdikov ◽  
Michael Markushev ◽  
Radik R. Mulyukov
Keyword(s):  
Strain Rate ◽  
Equal Channel Angular Pressing ◽  
High Strain ◽  
Strain Rate Range ◽  
Rate Range ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Excess Phases ◽  
Ultrafine Grained Microstructure ◽  
Zr Alloy

Unique superplastic elongations up to 4100% were achieved at 450°C in the strain rate range of 10-2-10-1s-1for Al-Mg-Sc-Zr alloy with a grain size ~1 μm processed by warm-to-hot equal channel angular pressing. Such a behavior is attributed to the synergy of complementary factors resulted in high homogeneity and stability of ultrafine-grained microstructure and superplastic flow, involving large proportion of high-angle grain boundaries, presence of dispersoids of aluminides of transition metals and negligible amount of coarse excess phases.

scholarly journals Development of ultrafine-grained microstructure in Al-Cu-Mg alloy through equal-channel angular pressing

2014 ◽  
Vol 63 ◽  
pp. 012082
Author(s):  
Danam Sai Anuhya ◽  
Ashutosh Gupta ◽  
Niraj Nayan ◽  
S V S Narayana Murty ◽  
R Manna ◽  
...  
Keyword(s):  
Equal Channel Angular Pressing ◽  
Mg Alloy ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Ultrafine Grained Microstructure

Evolution of the Microstructure of Al 6082 Alloy during Equal-Channel Angular Pressing

2005 ◽  
Vol 473-474 ◽  
pp. 453-458 ◽  
Author(s):  
Jenő Gubicza ◽  
György Krállics ◽  
I. Schiller ◽  
Dmitry Malgyn
Keyword(s):  
Dislocation Density ◽  
Crystallite Size ◽  
Equal Channel Angular Pressing ◽  
Profile Analysis ◽  
X Ray Diffraction ◽  
Characteristic Parameters ◽  
Diffraction Profile ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Ultrafine Grained Microstructure

A commercial Al-Mg-Si alloy (Al 6082) was deformed by Equal-Channel Angular Pressing (ECAP) to produce bulk ultrafine-grained microstructure. The crystallite size distribution and the characteristic parameters of the dislocation structure were investigated by X-ray diffraction profile analysis. It was found that the crystallite size decreased and the dislocation density increased during ECAP deformation. The increase of the yield stress of the alloy was related to the increase of the dislocation density using the Taylor model.

Heterogeneity and Anisotropy in Microstructure and Mechanical Properties of Pure Copper Processed by Equal Channel Angular Pressing

2006 ◽  
Vol 503-504 ◽  
pp. 663-668 ◽  
Author(s):  
Jing Tao Wang ◽  
Zhong Ze Du ◽  
Feng Kang ◽  
Guang Chen
Keyword(s):  
Mechanical Properties ◽  
Equal Channel Angular Pressing ◽  
Pure Copper ◽  
Coarse Grained ◽  
Angular Pressing ◽  
Hardness Tests ◽  
Ultrafine Grained ◽  
Average Grain Size ◽  
Property Anisotropy ◽  
Ultrafine Grained Microstructure

Pure copper (99.98%wt) square bars (32x32 mm) were processed by equal channel angular pressing (ECAP) Microstructure evolution was characterized by microscopy. Room temperature mechanical properties were obtained by tensile and micro-hardness tests. With increasing number of ECAP passes and cold rolling reductions, the initial coarse grained structure in the as-received material was transformed gradually into an ultrafine grained microstructure with an average grain size of 0.2~0.3 μm. Subsequent rolling resulted deformation twining in this ultrafine grained microstructure, which gives further strengthening in addition to the strengthening obtained by ECAP. Property anisotropy in three orthogonal directions of samples processed by ECAP was characterized by tensile testing.

Superplastic Behavior in Ultrafine-Grained Materials Produced by Equal-Channel Angular Pressing

2008 ◽  
Vol 579 ◽  
pp. 29-40 ◽  
Author(s):  
Cheng Xu ◽  
Megumi Kawasaki ◽  
Roberto B. Figueiredo ◽  
Zhi Chao Duan ◽  
Terence G. Langdon
Keyword(s):  
Equal Channel Angular Pressing ◽  
High Strain ◽  
Processing Method ◽  
Strain Rates ◽  
Bulk Materials ◽  
Superplastic Behavior ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Ultrafine Grained Materials ◽  
Aluminum And Magnesium Alloys

Equal-channel angular pressing (ECAP) is a convenient processing method for refining the grain size of bulk materials to the submicrometer level. Metallic alloys processed by ECAP often exhibit excellent superplastic characteristics including superplasticity at high strain rates. This paper summarizes recent experiments designed to evaluate the occurrence of superplasticity in representative aluminum and magnesium alloys and in the Zn-22% Al eutectoid alloy.

Processing of Copper by Equal Channel Angular Pressing (ECAP) – Microstructure Investigations

2015 ◽  
Vol 641 ◽  
pp. 286-293
Author(s):  
Beata Leszczyńska-Madej ◽  
Maria W. Richert ◽  
Agnieszka Hotloś ◽  
Jacek Skiba
Keyword(s):  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Subgrain Size ◽  
Pure Copper ◽  
Shear Bands ◽  
Angular Pressing ◽  
Ecap Process ◽  
Transmission Electron ◽  
Different Types ◽  
Diffraction Patterns

The present study attempts to apply Equal-Channel Angular Pressing (ECAP) to 99.99% pure copper. ECAP process was realized at room temperature for 4, 8 and 16 passes through route BC using a die having angle of 90°. The microstructure of the samples was investigated by means both light and transmission electron microscopy. Additionally the microhardness was measured and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns misorientation was determined. There were some different types of bands in the microstructure after deformation. The shear bands, bands and in the submicron range the microshear bands and microbands are a characteristic feature of the microstructure of copper. Also characteristic was increasing of the number of bands with increasing of deformation and mutually crossing of the bands. The intersection of a bands and microbands leads to the formation of new grains with the large misorientation angle. The measured grain/subgrain size show, that the grain size is maintained at a similar level after each stage of deformation and is equal to d = 0.25 – 0.32 μm.

Numerical Simulation of Microstructure Evolution in AZ31 Magnesium Alloy during Equal Channel Angular Pressing

2014 ◽  
Vol 609-610 ◽  
pp. 495-499
Author(s):  
Guo Cheng Ren ◽  
Xiao Juan Lin ◽  
Shu Bo Xu
Keyword(s):  
Finite Element ◽  
Magnesium Alloy ◽  
Equal Channel Angular Pressing ◽  
Microstructure Evolution ◽  
Element Model ◽  
Az31 Magnesium Alloy ◽  
Angular Pressing ◽  
Ecap Process ◽  
Element Simulation ◽  
3D Software

The microstructure and material properties of AZ31 magnesium alloy are very sensitive to process parameters, which directly determine the service properties. To explore and understand the deformation behavior and the optimization of the deformation process, the microstructure evolution during equal channel angular pressing was predicted by using the DEFORM-3D software package at different temperature. To verify the finite element simulation results, the microstructure across the transverse direction of the billet was measured. The results show that the effects strain and deformation temperatures on the microstructure evolution of AZ31 magnesium during ECAP process are significant, and a good agreement between the predicted and experimental results was obtained, which confirmed that the derived dynamic recrystallization mathematical models can be successfully incorporated into the finite element model to predict the microstructure evolution of ECAP process for AZ31 magnesium.

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