Equal Channel Angular Pressing of Metallic Powders for Nanostructured Materials

2006 ◽  
Vol 503-504 ◽  
pp. 221-226 ◽  
Author(s):  
Seung Chae Yoon ◽  
Hyoung Seop Kim
Keyword(s):  
Plastic Deformation ◽  
Nanostructured Materials ◽  
Equal Channel Angular Pressing ◽  
Powder Processing ◽  
Full Density ◽  
Bottom Up ◽  
Metallic Powders ◽  
Angular Pressing ◽  
Ecap Process ◽  
Strain And Strain Rate

In this study, bottom-up type powder processing and top-down type SPD (severe plastic deformation) approaches were combined in order to achieve both full density and grain refinement of metallic powders with least grain growth, which was considered as a bottle neck of the bottom-up method using the conventional powder metallurgy of compaction and sintering. ECAP (Equal channel angular pressing), one of the most promising method in SPD, was used for the powder consolidation. In the ECAP process of not only solid but also powder metals, knowledge of the density as well as internal stress, strain and strain rate distribution is important for understanding the process. We investigated the consolidation, plastic deformation and microstructure evolution behavior of the metallic powders during ECAP using experimental and theoretical methods. Almost independent behavior of powder densification in the entry channel and shear deformation in the main deformation zone was found by the finite element method in conjunction with a pressure dependent material yield model. It was found that high mechanical strength could be achieved effectively as a result of the well bonded powder contact surface during ECAP process of gas atomized Al-Si powders. The SPD processing of powders is a viable method to achieve both fully density and nanostructured materials.

Densification and Conolidation of Powders by Equal Channel Angular Pressing

2007 ◽  
Vol 534-536 ◽  
pp. 253-256 ◽  
Author(s):  
Seung Chae Yoon ◽  
Sun Ig Hong ◽  
Soon Hyung Hong ◽  
Hyoung Seop Kim
Keyword(s):  
Plastic Deformation ◽  
Equal Channel Angular Pressing ◽  
Powder Processing ◽  
Full Density ◽  
Bottom Up ◽  
Powder Consolidation ◽  
Metallic Powders ◽  
Angular Pressing ◽  
Ecap Process ◽  
Strain And Strain Rate

In this study, bottom-up type powder processing and top-down type SPD (severe plastic deformation) approaches were combined in order to achieve both full density and grain refinement of metallic powders with least grain growth, which is considered as a bottle neck of the bottom-up method that uses the conventional powder metallurgy of compaction and sintering. ECAP (Equal channel angular pressing), one of the most promising method in SPD, was used for the powder consolidation. In the ECAP process of not only solid but also powder metals, it is important to get a good understanding of the density as well as internal stress, strain and strain rate distribution. We investigated the consolidation, plastic deformation and microstructure evolution behavior of the metallic powders during ECAP using an experimental method. It was found that high mechanical strength could be achieved effectively due to the well bonded powder contact surface during ECAP process of gas atomized Al-Si powders. The experimental results show that SPD processing of powders is a viable method to achieve both fully density and nanostructured materials.

Achieving Both Powder Consolidation and Grain Refinement for Bulk Nanostructured Materials by Equal-Channel Angular Pressing

2007 ◽  
Vol 345-346 ◽  
pp. 173-176 ◽  
Author(s):  
Seung Chae Yoon ◽  
Do Minh Nghiep ◽  
Sun Ig Hong ◽  
Z. Horita ◽  
Hyoung Seop Kim
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Powder Metallurgy ◽  
Grain Refinement ◽  
Nanostructured Materials ◽  
Equal Channel Angular Pressing ◽  
Bottom Up ◽  
Powder Consolidation ◽  
Metallic Powders ◽  
Angular Pressing

Manufacturing bulk nanostructured materials with least grain growth from initial powders is challenging because of the bottle neck of bottom-up methods using the conventional powder metallurgy of compaction and sintering. In this study, bottom-up type powder metallurgy processing and top-down type SPD (Severe Plastic Deformation) approaches were combined in order to achieve both full density and grain refinement of metallic powders. ECAP (Equal-Channel Angular Pressing), one of the most promising processes in SPD, was used for the powder consolidation method. For understanding the ECAP process, investigating the powder density as well as internal stress, strain and strain rate distribution is crucial. We investigated the consolidation and plastic deformation of the metallic powders during ECAP using the finite element simulations. Almost independent behavior of powder densification in the entry channel and shear deformation in the main deformation zone was found by the finite element method in conjunction with a pressure dependent material yield model. Effects of processing parameters on densification and density distributions were investigated.

Equal Channel Angular Pressing of Carbon Nanotube Reinforced Metal Matrix Nanocomposites

2006 ◽  
Vol 326-328 ◽  
pp. 325-328 ◽  
Author(s):  
Quang Pham ◽  
Young Gi Jeong ◽  
Soon Hyung Hong ◽  
Hyoung Seop Kim
Keyword(s):  
Equal Channel Angular Pressing ◽  
Metal Matrix ◽  
Powder Processing ◽  
Full Density ◽  
Metal Matrix Nanocomposites ◽  
Powder Consolidation ◽  
Angular Pressing ◽  
Particle Bonding ◽  
Bottle Neck ◽  
Matrix Nanocomposites

In this study, powder processing and severe plastic deformation (SPD) approaches were combined in order to achieve both full density and good particle-matrix bonding in CNT and Cu powder mixtures without grain growth, which was considered as a bottle neck of the bottom-up method in the conventional powder metallurgy of compaction and sintering. Equal channel angular pressing (ECAP), one of the most promising methods in SPD, was used for the powder consolidation. The powder ECAP processing with 1, 2, 4 and 8 passes was conducted at room temperature. It was found by microhardness tests and microstructure characterization that relatively high mechanical strength could be effectively achieved as a result of the well bonded powder contact surface during powder ECAP. The SPD processing of powders is a viable method to achieve both fully density and good particle bonding in CNT-metal matrix nanocomposites.

scholarly journals PERUBAHAN NILAI KEKERASAN DAN KONDUKTIVITAS LISTRIK ALUMINIUM AKIBAT PROSES EQUAL CHANNEL ANGULAR PRESSING (ECAP)

ROTASI ◽  
2014 ◽  
Vol 16 (4) ◽  
pp. 41
Author(s):  
Rusnaldy Rusnaldy ◽  
Norman Iskandar ◽  
Muhammad Khairul Rais ◽  
Wisnu Tri Erlangga
Keyword(s):  
Electrical Conductivity ◽  
Plastic Deformation ◽  
Equal Channel Angular Pressing ◽  
Hardness Test ◽  
Hardness Measurement ◽  
Optical Microscope ◽  
Pure Aluminium ◽  
Angular Pressing ◽  
Ecap Process ◽  
Number Of Passes

In current study, Equal Channel Angular Pressing (ECAP) process was applied to pure aluminium rod. The effect of the number of passes on hardness and electrical conductivity ECAP samples was investigated. The dimensions of ECAP die for 12 mmm diameter workpieces are designed with intersect angle of 120o. The experiments were carried out by using samples cut from an ingot and a rod and machined to a size of 12 mm in diameter and 50 mm in length. The workpiece was pressed into the ECAP die up to 7 passes at room temperature.After deformation, all samples were subjected to a hardness test, an electrical conductivity test and for optical microscope study. The hardness measurement of the ECAP samples suggested that enhanced hardness would be obtained by repeating ECAP process.Increasing the electrical conductivity of the ECAP samples indicatesthat there is no dislocation formation due to increasing plastic deformation in ECAP process

Influence of Plastic Deformation during ECAP on Precipitation Temperature of γ″ in IN 718 Alloy

2006 ◽  
Vol 118 ◽  
pp. 431-436
Author(s):  
Il Ho Kim ◽  
S.I. Kwun
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Equal Channel Angular Pressing ◽  
Aging Treatment ◽  
Hardness Test ◽  
Microstructural Observation ◽  
Angular Pressing ◽  
Ecap Process ◽  
Before And After ◽  
Formation Behavior

The formation behavior of γ″(Ni3Nb) precipitates in IN 718 alloy before and after ECAP(equal channel angular pressing) was investigated by microstructural observation and the hardness test. For the alloy examined before ECAP, the γ″ precipitates were formed only after aging treatment at 720, whereas after ECAP, the γ″ precipitates were formed at the aging temperatures of both 600 and 720. 600 is normally too low a temperature for γ″ precipitates to be formed in commercial IN 718 alloy, however, they were able to be formed due to severe plastic deformation by ECAP. It was found that the ECAP process changed the formation behavior of the γ″ precipitates in IN 718 alloy.

Equal Channel Angular Pressing and Torsion of Pure Al Powder in Tubes

2010 ◽  
Vol 97-101 ◽  
pp. 1109-1115 ◽  
Author(s):  
Xiao Xi Wang ◽  
Ke Min Xue ◽  
Ping Li ◽  
Zhan Li Wu ◽  
Qi Li
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Equal Channel Angular Pressing ◽  
Bulk Material ◽  
Full Density ◽  
Powder Materials ◽  
Angular Pressing ◽  
Average Grain Size ◽  
Al Powder ◽  
Set Up

In this work, a new severe plastic deformation technique for preparing bulk fine-grained materials has been developed to achieve higher plasticity of powder materials. This novel technique, named Equal Channel Angular Pressing and Torsion (ECAPT), combines two severe plastic deformation methods: equal channel angular pressing and twist extrusion. With the designed ECAPT set-up, pure Al powder particles were successfully consolidated into full dense bulk material with fine grains at a lower deformation temperature (200°C) by Powder in Tubes-Equal Channel Angular Pressing and Torsion (PITS-ECAPT). After two passes of PITS-ECAPT, the microstructures at X, Y and Z planes of each sample were all sheared and elongated along a certain direction with fine banded structures; the grains were greatly squashed and refined with an average grain size of ~ 11.90µm; the deformed sample reached the full density; the micro-hardness and yield strength achieved 49.9kg/mm2 and 155Mpa respectively, which were significantly higher than those of as-cast annealed pure Al and pure Al powder sintered materials.

Carbon Nanotube Reinforced Metal Matrix Nanocomposites via Equal Channel Angular Pressing

2007 ◽  
Vol 534-536 ◽  
pp. 245-248 ◽  
Author(s):  
Quang Pham ◽  
Young Gi Jeong ◽  
Seung Chae Yoon ◽  
Sun Ig Hong ◽  
Soon Hyung Hong ◽  
...  
Keyword(s):  
Metal Matrix Composites ◽  
Equal Channel Angular Pressing ◽  
Metal Matrix ◽  
Full Density ◽  
Matrix Composites ◽  
Ecap Processing ◽  
Bottom Up ◽  
Metal Matrix Nanocomposites ◽  
Angular Pressing ◽  
Particle Bonding

Carbon nanotubes (CNTs) have been the subject of intensive study for applications in the fields of nanotechnologies in recent years due to their superior mechanical, electric, optical and electronic properties. Because of their exceptionally small diameters (≈ several nm) as well as their high Young’s modulus (≈ 1 TPa), tensile strength (≈ 200 GPa) and high elongation (10-30%) in addition to a high chemical stability, CNTs are attractive reinforcement materials for light weight and high strength metal matrix composites. In this study, bottom-up type powder processing and top-down type SPD (severe plastic deformation) approaches were combined in order to achieve full density of CNT/metal matrix composites with superior mechanical properties by improved particle bonding and least grain growth, which were considered as a bottle neck of the bottom-up method using the conventional powder metallurgy of compaction and sintering. ECAP (equal channel angular pressing), the most promising method in SPD, was used for the CNT/Cu powder consolidation. The powder ECAP processing with 1, 2, 4 and 8 route C passes was conducted at room temperature. It was found by mechanical testing of the consolidated CNT/Cu that high mechanical strength could be achieved effectively as a result of the Cu matrix strengthening and improved particle bonding during ECAP. The ECAP processing of powders is a viable method to achieve fully density CNT-Cu nanocomposites.

Analytical and Numerical Modelling of Strain and Strain Rate in Equal Channel Angular Pressing (ECAP)

2006 ◽  
Vol 306-308 ◽  
pp. 965-970
Author(s):  
Hyoung Seop Kim
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Strain Rate ◽  
Equal Channel Angular Pressing ◽  
The Finite Element Method ◽  
Angular Pressing ◽  
Geometric Conditions ◽  
Strain And Strain Rate ◽  
Element Method

Equal channel angular pressing (ECAP) is a convenient forming procedure among various severe plastic deformation processes. It is based on extruding material through specially designed entry and exit channel dies to produce an ultrafine grained microstructure. The properties of the materials obtained depend on the plastic deformation behaviour during ECAP, which is governed mainly by the die geometry, the material itself and the processing conditions. As the mechanical properties of the severely deformed material are directly related to the deformation history, understanding the phenomena associated with strain and strain rate development in the ECAP process is very important. In this study, the results of continuum modelling of ECAP are described in order to understand strain and strain developments. For this purpose, the results of modelling ECAP using the finite element method and analytical solution are presented for various geometric conditions. It was concluded that although deformation is nonuniform due to geometric effects, the strain and strain rate values obtained by the analytical solutions are not much different from the average results of the finite element method.

Effect of Addition of Some Grain Refiners to Zinc-Aluminum 22, ZA22, Alloy on its Grain Size, Mechanical Characteristics in the Cast and after Pressing by the Equal Channel Angular Pressing, ECAP

2015 ◽  
Vol 1105 ◽  
pp. 172-177 ◽  
Author(s):  
Adnan I.O. Zaid ◽  
Jehad A.S. AlKasasbeh ◽  
S.M.A. Al-Qawabah
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
Equal Channel Angular Pressing ◽  
Mechanical Characteristics ◽  
The Other ◽  
Angular Pressing ◽  
Ecap Process ◽  
Maximum Decrease ◽  
Cast Condition

In this paper, the effect of addition of some grain refiners namely: molybdenum, titanium and titanium+boron to zinc-aluminum 22%, ZA22, alloy on its microstructure and mechanical characteristics is investigated in two conditions one in the cast condition and the other after pressing by the equal channel angular pressing, ECAP. Recently the ECAP process has been used to produce severe plastic deformation. It was found that addition of any of these elements to ZA22 alloy resulted in grain refinement of its structure both in the cast and after pressing by the ECAP conditions, being more pronounced after pressing by ECAP. The maximum decrease was %. Furthermore, it resulted in enhancement of its mechanical strength at, indicating softening of the alloy. Regarding the effect on its hardness, it decreased by th addition of either Mo or Ti+B. at any rate of Mo addition.

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