scholarly journals Hardness and Texture of Electrolytic Copper Processed by ECAP at Ambient and Warm Temperature

2021 ◽  
Vol 31 (2) ◽  
pp. 74-87
Author(s):  
Hiron Akira Yamada Magalhães ◽  
Talita Gama Souza ◽  
Rodrigo Felix de Araujo Cardoso ◽  
Bruno Rangel Silva ◽  
Luiz Paulo Brandão
Keyword(s):  
Pure Copper ◽  
Homogeneous Distribution ◽  
Warm Temperature ◽  
Mechanical Hardness ◽  
Angular Pressing ◽  
Ecap Process ◽  
Hardness Property ◽  
Textural Changes ◽  
The One ◽  
Strength And Ductility

Among several severe plastic deformation (SPD) methods, the Equal Channel Angular Pressing (ECAP) process is one of the most popular. This process's main characteristic is producing materials with ultra-fine or nanometric grains. Due to these microstructural changes, it is possible to improve mechanical properties such as strength and ductility. In this perspective, the aim of the present work was to evaluate the variations of the mechanical hardness property associated with microstructural and textural changes of pure copper as a function of its processing by SPD via ECAP. For this, the material was submitted to four passes through routes A (the sample is repetitively pressed without any rotation between each pass) and Bc (the sample is rotated in the same sense by 90° between each pass) at cold and warm temperatures. Through the obtained result, it was verified that the ambient temperature of the Bc route was the one that promoted greater homogeneity in the microstructure and weakening of the texture after the fourth pass. On the other hand, warm processing of copper by ECAP promoted a softening of the samples and a homogeneous distribution of hardness in both routes.

scholarly journals Applying Hybrid Equal Channel Angular Pressing (HECAP) to pure copper using optimized Exp.-ECAP die

2021 ◽  
Author(s):  
Serkan Öğüt ◽  
Hasan Kaya ◽  
Aykut Kentli ◽  
Mehmet UÇAR
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
Pure Copper ◽  
Mechanical Tests ◽  
Geometric Parameters ◽  
Homogeneous Distribution ◽  
Angular Pressing ◽  
Ecap Process

Abstract Equal channel angular pressing (ECAP), expansion equal channel angular pressing (Exp.-ECAP) and hybrid equal channel angular pressing (HECAP) processes were applied to pure copper specimens within this study. Before the ECAP and HECAP processes, an Exp.-ECAP mold with optimum geometric parameters was produced to be used in these processes. The samples, on which ECAP, Exp.-ECAP and HECAP processes were applied, were subjected to microstructure analysis and mechanical tests, and the effects of these processes were examined. The results obtained showed that the Exp.-ECAP process gave better results in grain refinement and mechanical properties, and the Exp.-ECAP passes applied after the ECAP process within the scope of the HECAP process provided a more homogeneous distribution for grain size and hardness.

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.

scholarly journals Mechanical Properties of Copper Processed by Equal Channel Angular Pressing

2017 ◽  
Vol 17 (2) ◽  
pp. 124-129
Author(s):  
K. Sülleiová ◽  
B. Ballóková ◽  
M. Besterci ◽  
T. Kvačkaj
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Equal Channel Angular Pressing ◽  
Dynamic Equilibrium ◽  
Pure Copper ◽  
Angular Pressing ◽  
Static Tensile ◽  
Strength And Ductility ◽  
Test Stress

Abstract The development of the nanostructure in commercial pure copper and the strength and ductility after severe plastic deformation (SPD) with the technology of equal channel angular pressing (ECAP) are analysed. Experimental results and analyses showed that both strength and ductility can be increased simultaneously by SPD. The final grain size decreased from the initial 50μm by SPD to 100-300 nm after 10 passes. An increase of the ductility together with an increase of strength caused by SPD are explained by a strong grain refinement and by a dynamic equilibrium of weakening and strengthening, and it is visible on the final static tensile test stress-strain charts.

Tensile Properties and Fatigue Strength of Ultrafine Grained Pure Copper

2007 ◽  
Vol 353-358 ◽  
pp. 1649-1652
Author(s):  
Masahiro Goto ◽  
Seung Zeon Han ◽  
Sang Shik Kim ◽  
Norio Kawagoishi ◽  
Cha Yong Lim
Keyword(s):  
Tensile Strength ◽  
Pure Copper ◽  
Surface Hardness ◽  
Fatigue Tests ◽  
Cyclic Stresses ◽  
Angular Pressing ◽  
Ecap Process ◽  
Ultrafine Grained ◽  
Increasing Trend ◽  
Surface Morphologies

Oxygen-free copper was processed by equal channel angular pressing with different numbers of ECAP process cycles, NP. Tensile strength was increased with an increase in NP, but it tended to saturate after NP = 4. Conversely, elongation was dramatically decreased by first pressing, but it tended to saturate up to NP = 3, followed by slight increasing trend after NP = 4. Fatigue tests of specimens processed with NP = 4 and 8 were performed. The change in surface morphologies during fatigue was monitored successively. In addition to this, the change in surface hardness was measured. Significant decrease in surface hardness due to cyclic stresses was measured. The physical basis of fatigue damage of UFG copper was discussed based on the experimental results.

scholarly journals Experimental and Numerical Investigation of the ECAP Processed Copper: Microstructural Evolution, Crystallographic Texture and Hardness Homogeneity

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 607
Author(s):  
A. I. Alateyah ◽  
Mohamed M. Z. Ahmed ◽  
Yasser Zedan ◽  
H. Abd El-Hafez ◽  
Majed O. Alawad ◽  
...  
Keyword(s):  
Grain Size ◽  
Equal Channel Angular Pressing ◽  
Cross Section ◽  
Room Temperature ◽  
Pure Copper ◽  
High Density ◽  
Ecap Processing ◽  
Heterogeneous Distribution ◽  
Angular Pressing ◽  
Average Grain Size

The current study presents a detailed investigation for the equal channel angular pressing of pure copper through two regimes. The first was equal channel angular pressing (ECAP) processing at room temperature and the second was ECAP processing at 200 °C for up to 4-passes of route Bc. The grain structure and texture was investigated using electron back scattering diffraction (EBSD) across the whole sample cross-section and also the hardness and the tensile properties. The microstructure obtained after 1-pass at room temperature revealed finer equiaxed grains of about 3.89 µm down to submicrons with a high density of twin compared to the starting material. Additionally, a notable increase in the low angle grain boundaries (LAGBs) density was observed. This microstructure was found to be homogenous through the sample cross section. Further straining up to 2-passes showed a significant reduction of the average grain size to 2.97 µm with observable heterogeneous distribution of grains size. On the other hand, increasing the strain up to 4-passes enhanced the homogeneity of grain size distribution. The texture after 4-passes resembled the simple shear texture with about 7 times random. Conducting the ECAP processing at 200 °C resulted in a severely deformed microstructure with the highest fraction of submicron grains and high density of substructures was also observed. ECAP processing through 4-passes at room temperature experienced a significant increase in both hardness and tensile strength up to 180% and 124%, respectively.

scholarly journals Investigation on the Microstructure of ECAP-Processed Iron-Aluminium Alloys

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 219
Author(s):  
Bernd-Arno Behrens ◽  
Kai Brunotte ◽  
Tom Petersen ◽  
Roman Relge
Keyword(s):  
Grain Refinement ◽  
Aluminium Alloys ◽  
Aluminium Content ◽  
Microstructure Development ◽  
Chamber Furnace ◽  
Fine Grained ◽  
Angular Pressing ◽  
Ecap Process ◽  
Average Grain Size ◽  
Forming Temperature

The present work deals with adjusting a fine-grained microstructure in iron-rich iron-aluminium alloys using the ECAP-process (Equal Channel Angular Pressing). Due to the limited formability of Fe-Al alloys with increased aluminium content, high forming temperatures and low forming speeds are required. Therefore, tool temperatures above 1100 °C are permanently needed to prevent cooling of the work pieces, which makes the design of the ECAP-process challenging. For the investigation, the Fe-Al work pieces were heated to the respective hot forming temperature in a chamber furnace and then formed in the ECAP tool at a constant punch speed of 5 mm/s. Besides the chemical composition (Fe9Al, Fe28Al and Fe38Al (at.%—Al)), the influences of a subsequent heat treatment and the holding time on the microstructure development were investigated. For this purpose, the average grain size of the microstructure was measured using the AGI (Average Grain Intercept) method and correlated with the aforementioned parameters. The results show that no significant grain refinement could be achieved with the parameters used, which is largely due to the high forming temperature significantly promoting grain growth. The holding times in the examined area do not have any influence on the grain refinement.

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.

scholarly journals STRUCTURE AND PROPERTIES OF AZ31 MAGNESIUM ALLOY AFTER COMBINATION OF HOT EXTRUSION AND ECAP

2017 ◽  
Vol 23 (3) ◽  
pp. 222 ◽  
Author(s):  
Ondřej Hilšer ◽  
Stanislav Rusz ◽  
Wojciech Maziarz ◽  
Jan Dutkiewicz ◽  
Tomasz Tański ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Hot Extrusion ◽  
Az31 Magnesium Alloy ◽  
Initial State ◽  
Fine Grained ◽  
Angular Pressing ◽  
Ecap Process ◽  
Average Grain Size ◽  
Fine Grained Structure

<p>Equal channel angular pressing (ECAP) method was used for achieving very fine-grained structure and increased mechanical properties of AZ31 magnesium alloy. The experiments were focused on the, in the initial state, hot extruded alloy. ECAP process was realized at the temperature 250°C and following route Bc. It was found that combination of hot extrusion and ECAP leads to producing of material with significantly fine-grained structure and improves mechanical properties. Alloy structure after the fourth pass of ECAP tool with helix matrix 30° shows a fine-grained structure with average grain size of 2 µm to 3 µm and high disorientation between the grains. More experimental results are discussed in this article.</p>

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