scholarly journals Analysis of non-equal-channel angular pressing scheme applied for obtaining magnesium sheet in cold state

2019 ◽  
pp. 59-66
Author(s):  
Yu. N. Loginov ◽  
A. Yu Volkov ◽  
B. I. Kamenetsky
Keyword(s):  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Cold Extrusion ◽  
Relative Reduction ◽  
Energy Costs ◽  
Percentage Reduction ◽  
Sheet Rolling ◽  
Angular Pressing ◽  
Sheet Blank ◽  
High Level

Deformation patterns of rolling, equal-channel angular pressing and non-equal-channel angular pressing were evaluated. It is noted that when rolling, it is difficult to transfer a circular section preform into a rectangular section with a small thickness. This problem cannot be solved using equal-channel angular pressing. In connection with this, it is proposed to use a non-equal-channel angular pressing pattern to study the cast structure of magnesium. An experimental procedure based on cold extrusion of cylinders with a diameter of 42 mm and a height of 40 mm is described. The strip at the outlet was 40 mm in width and 1 mm in thickness. The percentage reduction of the preform material determined by the ratio of areas was 96 % with a draw ratio of 17. The specific pressures on the punch at the beginning ofthe extrusion process were 1200—1300 MPa, and extrusion force was 1670—1800 kN. The preform was cut into lengths that were rolled at a room temperature into 50 and 10 pm thick foils without intermediate annealing. Rolling was carried out on the Duo mill with a percentage reduction of 12—20 % at an average speed of 0,1 m/s. 20 passes were performed with a total relative reduction of 95 % to make the 50 pm thick foil. The results of computer simulation by the finite element method demonstrated that the constant value of the deformation degree is achieved at a rather considerable distance from the front end estimated as 50 times the thickness of the strip. The deformation rate field was calculated to determine the configuration of the deformation center. Energy costs were estimated. As a result of the completed set of calculated and experimental work, it was possible to establish the following — it is possible to produce a thin sheet preform from a cylindrical cast magnesium blank in one operation at a room temperature. The sheet blank has a level of ductility sufficient for subsequent sheet rolling. The sheet blank obtained in the proposed process has a high level of plastic deformation elaboration created due to the forming pattern with the high level of elongation and shear deformation. Despite the high level of pressure that must be applied to create a comprehensive compression scheme taking into account the lack of the need to heat the preform, energy costs are no higher than in traditional treatment processes.

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.

Effect of Equal-Channel Angular Pressing (ECAP) on Creep in Aluminium Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 2904-2909 ◽  
Author(s):  
Vàclav Sklenička ◽  
Jiří Dvořák ◽  
Marie Kvapilová ◽  
Milan Svoboda ◽  
Petr Král ◽  
...  
Keyword(s):  
Equal Channel Angular Pressing ◽  
Aluminium Alloys ◽  
Creep Resistance ◽  
Room Temperature ◽  
Creep Behaviour ◽  
Coarse Grained ◽  
Pure Aluminium ◽  
Creep Tests ◽  
Angular Pressing ◽  
Compression Creep

This paper examines the effect of equal-channel angular pressing (ECAP) on creep behaviour of pure aluminium, binary Al-0.2wt.%Sc alloy and ternary Al-3wt.%Mg-0.2wt.%Sc alloy. The ECAP was conducted at room temperature with a die that had a 90° angle between the channels and 8 repetitive ECAP passes followed route BC. Constant stress compression creep tests were performed at 473 K and stresses ranging between 16 to 80 MPa on ECAP materials and, for comparison purposes, on the initial coarse-grained materials. The results showed that the creep resistance of the ECAP processed Al-Sc and Al-Mg-Sc alloys was markedly deteriorated with respect to unpressed coarse-grained materials.

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.

Strength of Commercial Aluminum Alloys after Equal Channel Angular Pressing and Post-ECAP Processing

2006 ◽  
Vol 114 ◽  
pp. 91-96 ◽  
Author(s):  
Maxim Yu. Murashkin ◽  
M.V. Markushev ◽  
Julia Ivanisenko ◽  
Ruslan Valiev
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloys ◽  
Ultimate Tensile Strength ◽  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Solution Treatment ◽  
Ecap Processing ◽  
Angular Pressing

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.

Room temperature equal-channel angular pressing of a magnesium alloy

2013 ◽  
Vol 61 (8) ◽  
pp. 3027-3036 ◽  
Author(s):  
C.F. Gu ◽  
L.S. Tóth ◽  
D.P. Field ◽  
J.J. Fundenberger ◽  
Y.D. Zhang
Keyword(s):  
Magnesium Alloy ◽  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Angular Pressing

Influence of aging on mechanical properties of equal channel angular pressed aluminum alloy 7075

2015 ◽  
Vol 231 (10) ◽  
pp. 1803-1811 ◽  
Author(s):  
Seyed Mahmoud Ghalehbandi ◽  
Alireza Fallahi Arezoodar ◽  
Hossein Hosseini-Toudeshky
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Subsequent Aging ◽  
Good Ductility ◽  
Angular Pressing ◽  
Aluminum Alloy 7075

Effect of aging treatment on mechanical properties of an age-hardenable aluminum alloy after equal channel angular pressing at room temperature has been investigated using hardness, stress–strain behavior and surface fractography. Aluminum alloy 7075 was pressed after solution treatment. Yield stress, ultimate stress and hardness of pressed samples have increased significantly compared with those of coarse grain, but the elongation to failure has decreased. Also the pressed specimens were subjected to aging treatment at room temperature and temperatures of 80 °C, 100 °C, 120 °C and 140 °C to obtain the optimized strength and ductility. The results indicated that post–equal channel angular pressing aging at 80 °C has resulted in the maximum strength, and natural aging has resulted in good ductility and acceptable strength. It confirmed the fact that there is a potential in obtaining high strength and good ductility in age-hardenable alloys employing severe plastic deformation and subsequent aging.

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