Recrystallization Texture of Ferrite Steels: Beyond the γ-Fibre

2011 ◽  
Vol 702-703 ◽  
pp. 790-793 ◽  
Author(s):  
Patricia Gobernado ◽  
Roumen H. Petrov ◽  
Jaap Moerman ◽  
Carla Barbatti ◽  
Leo Kestens
Keyword(s):  
High Resolution ◽  
Deep Drawing ◽  
Recrystallization Texture ◽  
Essential Role ◽  
Plastic Anisotropy ◽  
Plastic Instability ◽  
Scanning Microscopy ◽  
Nucleation Process ◽  
Localized Deformation ◽  
Cross Rolling

The recrystallization texture of highly cold deformed IF steels is addressed. The latter is characterized by the //ND fibre and a certain spread towards the {311} orientation. The //ND fibre is the optimum texture for enhanced deep-drawing properties whereas the presence of any other component, such as {311}, will deteriorate the plastic anisotropy of the material. Previous works concluded that the recrystallized {311} orientation results from an oriented nucleation process related to the plastic instability of {001} deformed grains. In the present work, the microstructural nature of such plastic instability is investigated by high resolution orientation scanning microscopy on an annealed IF sample after cross-rolling. Present data indicate that localized deformation in near {001} grains plays an essential role in the nucleation of {311} orientations.

scholarly journals Prediction of Earing of Cross-Rolled Al Sheets from {h00} Pole Figures

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 192
Author(s):  
Marton Benke ◽  
Bence Schweitzer ◽  
Adrienn Hlavacs ◽  
Valeria Mertinger
Keyword(s):  
Deep Drawing ◽  
Plastic Anisotropy ◽  
Rolling Texture ◽  
X Ray Diffraction ◽  
Cross Rolling ◽  
X Ray ◽  
Aluminum Sheets ◽  
Pole Figures ◽  
Cold Rolling Texture ◽  
First Time

The plastic anisotropy of rolled Al sheets is the result of a crystallographic texture. It leads to the formation of uneven cup heights during deep-drawing, which is called earing. A new, simple and rapid method had been previously developed by the authors to predict earing directly from {h00} pole figures. In the present manuscript, this method is applied to cross-rolling for the first time. 5056 type aluminum sheets were unidirectionally- (conventionally) and cross-rolled from 4 to ~1 mm thickness in 6 or 12 passes. Earing was predicted from recalculated {200} pole figures obtained after X-ray diffraction texture measurements. The results were validated by deep-drawing tests. It is shown that the proposed method predicts the type (locations of ears) and magnitude of earing with satisfactory results. However, a different scaling factor must be used to calculate the magnitude of earing for cross-rolling than for unidirectional rolling even if all other parameters (including cold rolling, texture measurements, and deep-drawing) are the same. This is because the cross-rolled sheets exhibit a similar type but weaker earing compared to the unidirectionally rolled samples.

Examination of Schistosome Cercariae and Schistosomules by Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 50-51
Author(s):  
D. Johnson ◽  
P. Moriearty
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Light Microscopy ◽  
Surface Structure ◽  
Extensive Study ◽  
Scanning Microscopy ◽  
Host Parasite ◽  
Conventional Electron Microscopy ◽  
Scanning Electron

Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.

scholarly journals Experimental Investigation on Micro Deep Drawing of Stainless Steel Foils with Different Microstructural Characteristics

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Jingwei Zhao ◽  
Tao Wang ◽  
Fanghui Jia ◽  
Zhou Li ◽  
Cunlong Zhou ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Deep Drawing ◽  
Annealing Temperature ◽  
Localized Deformation ◽  
Microstructural Characteristics ◽  
Height Profile ◽  
Annealing Temperatures ◽  
Micro Deep Drawing ◽  
Profile Distribution

AbstractIn the present work, austenitic stainless steel (ASS) 304 foils with a thickness of 50 µm were first annealed at temperatures ranging from 700 to 1100 ℃ for 1 h to obtain different microstructural characteristics. Then the effects of microstructural characteristics on the formability of ASS 304 foils and the quality of drawn cups using micro deep drawing (MDD) were studied, and the mechanism involved was discussed. The results show that the as-received ASS 304 foil has a poor formability and cannot be used to form a cup using MDD. Serious wrinkling problem occurs on the drawn cup, and the height profile distribution on the mouth and the symmetry of the drawn cup is quite non-uniform when the annealing temperature is 700 ℃. At annealing temperatures of 900 and 950 ℃, the drawn cups are both characterized with very few wrinkles, and the distribution of height profile, symmetry and mouth thickness are uniform on the mouths of the drawn cups. The wrinkling becomes increasingly significant with a further increase of annealing temperature from 950 to 1100 ℃. The optimal annealing temperatures obtained in this study are 900 and 950 ℃ for reducing the generation of wrinkling, and therefore improving the quality of drawn cups. With non-optimized microstructure, the distribution of the compressive stress in the circumferential direction of the drawn foils becomes inhomogeneous, which is thought to be the cause of the occurrence of localized deformation till wrinkling during MDD.

High-resolution differential thermography of integrated circuits with optical feedback laser scanning microscopy

2005 ◽  
Vol 87 (23) ◽  
pp. 231104 ◽  
Author(s):  
Carlo Mar Blanca ◽  
Vernon Julius Cemine ◽  
Vera Marie Sastine ◽  
Caesar Saloma
Keyword(s):  
High Resolution ◽  
Integrated Circuits ◽  
Laser Scanning ◽  
Optical Feedback ◽  
Laser Scanning Microscopy ◽  
Scanning Microscopy

Improved Formability and Deep Drawing of Cross-Rolled Magnesium Alloy Sheets at Elevated Temperatures

2005 ◽  
Vol 488-489 ◽  
pp. 461-464 ◽  
Author(s):  
Yong Chao Xu ◽  
Shi Hong Zhang ◽  
H.M. Liu ◽  
Z.T. Wang ◽  
W.T. Zheng ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Deep Drawing ◽  
Elevated Temperatures ◽  
Rolling Direction ◽  
Alloy Sheet ◽  
Rolled Sheet ◽  
Drawing Ratio ◽  
Cross Rolling ◽  
Magnesium Alloy Sheet ◽  
Cylindrical Cup

The extruded sheets were prepared at the temperature between 350ıand 400ı, and the magnesium alloy sheet was manufactured by a new method, cross rolling, in which the rolling direction was changed in each pass. At the time, deep drawing of magnesium alloy sheet was investigated at elevated temperatures. The results show that the sheet has refined-grain by cross-rolling after it was annealed at 250ı, and the formability is significantly improved at lower temperatures, which is superior to the extruded sheet and the one-way rolled sheet. Deep drawing of magnesium alloy was performed successfully, and cylindrical cup of limited drawing ratio (LDR) 2.6 and 35 mm deep rectangular box (65ı50) was achieved at the lower temperature of 170ı. The different types of fracture were analyzed and reasonable parameters were determined.

Plastic Instability of Thin Shells Deformed by Rigid Punches and by Hydraulic Pressure

1973 ◽  
Vol 95 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Bilgin Kaftanog˘lu
Keyword(s):  
Large Deformations ◽  
Initial Conditions ◽  
Plastic Anisotropy ◽  
Plastic Instability ◽  
Strain History ◽  
Thin Shells ◽  
Hydraulic Pressure ◽  
Varying Thickness ◽  
New Criterion ◽  
Hydraulic Bulging

A theory has been developed to provide a solution for axisymmetrical shells in the plastic range for large deformations up to fracture. It includes the effects of strain history, nonlinear strain-hardening characteristics of materials, plastic anisotropy in the thickness direction, prestrain, through-thickness stress, and boundary tractions. It is also possible to use nonuniform initial conditions such as varying thickness and varying prestrain. A numerical solution has been developed especially suitable for stretch forming by a rigid punch and for hydraulic bulging of shells or diaphragms. It can easily be modified for the deep-drawing problem. Different instability criteria have been studied. It was found that the conventional criteria would not yield satisfactory results. A new criterion called the “strain propagation” criterion gave satisfactory results in the prediction of the onset of fracture. It could expalin the fracture taking place at increasing or decreasing pressures in the hydraulic bulging problem.

On the Modeling of Evolving Elastic and Plastic Anisotropy in the Finite Strain Regime – Application to Deep Drawing Processes

2012 ◽  
Vol 504-506 ◽  
pp. 679-684 ◽  
Author(s):  
Ivaylo N. Vladimirov ◽  
Michael P. Pietryga ◽  
Vivian Tini ◽  
Stefanie Reese
Keyword(s):  
Deep Drawing ◽  
Evolution Equations ◽  
Finite Strain ◽  
Kinematic Hardening ◽  
Plastic Anisotropy ◽  
Material Model ◽  
Internal Variables ◽  
Time Step ◽  
Finite Element Software ◽  
Structure Tensors

In this work, we discuss a finite strain material model for evolving elastic and plastic anisotropy combining nonlinear isotropic and kinematic hardening. The evolution of elastic anisotropy is described by representing the Helmholtz free energy as a function of a family of evolving structure tensors. In addition, plastic anisotropy is modelled via the dependence of the yield surface on the same family of structure tensors. Exploiting the dissipation inequality leads to the interesting result that all tensor-valued internal variables are symmetric. Thus, the integration of the evolution equations can be efficiently performed by means of an algorithm that automatically retains the symmetry of the internal variables in every time step. The material model has been implemented as a user material subroutine UMAT into the commercial finite element software ABAQUS/Standard and has been used for the simulation of the phenomenon of earing during cylindrical deep drawing.

Texture Evolution and Earing in Aluminium Can Sheet

2005 ◽  
Vol 495-497 ◽  
pp. 1565-1572 ◽  
Author(s):  
Jürgen Hirsch
Keyword(s):  
Fourier Series ◽  
Cold Rolling ◽  
Series Expansion ◽  
Deep Drawing ◽  
Recrystallization Texture ◽  
Texture Evolution ◽  
Processing Parameters ◽  
New Method ◽  
Fourier Series Expansion ◽  
Hot And Cold Rolling

The texture evolution during hot and cold rolling of AlMg1Mn1 can body sheet is described and the related anisotropy effects during deep drawing are analysed quantitatively. The typical textures of rolled aluminium show the transition between ß-fibre orientations and cube recrystallization texture, depending on rolling temperature and strain. These correlate with transitions between 45° and 0°/90° ear heights in deep drawn cups which are described by a new method of Fourier series expansion. Processing parameters to achieve low anisotropy are discussed.

Measurement and prediction of plastic anisotropy in deep-drawing steels

1990 ◽  
Vol 21 (1) ◽  
pp. 331-343 ◽  
Author(s):  
D. Daniel ◽  
J. J. Jonas
Keyword(s):  
Deep Drawing ◽  
Plastic Anisotropy
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