Metal Deformation Processes Research Articles

Mesoscale Modeling of Microstructure and Texture Evolution During Deformation Processing of Metals

The application of the finite element method to model the deformation of metals at the mesoscale to study the microstructure and texture evolution is described. The finite element discretization is applied directly to the various grains, and crystal plasticity is used as the constitutive basis to model the plastic deformation by crystallographic slip, and to evolve the slip system strength and crystal lattice orientation of the material. Applications of the methodology to detailed studies of the non-uniform deformations of individual grains, and effects of grain interactions on the distributions of deformation and stress in the microstructure are discussed.

Microstructure Characterization of Dislocation Wall Structure in Aluminum Using Transmission Electron Microscopy

The configuration of dislocation wall structures and the interactions between dislocations and dislocation walls play a significant role in the understanding of deformation processes in metals. Samples of single-crystal aluminum deformed by tensile-straining (15%) were analyzed using TEM. In tensile-deformed (15%) single crystal aluminum, a cell structure is well developed and dislocations in the cell boundaries consist of either one set of Burgers vector or two sets of Burgers vector. The three-dimensional image of cell wall structure, misorientation angle across the cell boundaries and the Burgers vectors of dislocations in the cell boundaries are characterized.

Finishing of non-ferrous internal surfaces using ballizing technique

Tubular parts are important in many industrial applications (e.g., joints, fittings, etc.). The internal surface quality plays a role in part performance. Non-ferrous internal surfaces are difficult-to-finish due to many problems encountered in grinding which is optimum for ferrous metals. Ballizing, as a metal deformation process, is believed to be more suitable since it eliminates sticking, wheel dulling and overheating. In this work, finishing of internal surfaces of aluminum using a ball-headed tool was carried out by holding a tubular specimen on the lathe jaw chuck, rotating it and then pushing an oversized steel ball-shaped tool, clamped to the tool post, into the specimen bore. Specimen rotating speeds of 250, 315, 500 and 800 rpm, tool feed rates of 0.078, 0.098, 0.314 and 0.589 mm/rev; and depths of penetration (interference) of 100, 200, 300 and 400 mm were used. Surface roughness (represented by R a) proved to be improved by the process to an optimum speed, feed and clearance. Such improvement could be explained at the light of the nature of depth of penetration. Outer surface strains were proportional to the depth of penetration and also optimization was observed for both speed and feed. The process gave a stressed and hardened surfaces which represents an advantage.

Behavior of sheet metal submitted to cyclic bending and stationary drawing deformation

A sheet metal deformation process based upon bending combined with drawing has been developed with FEM numerical simulation assisted with simple experimental device. Careful experimental measurements combined with 3D numerical simulation identified the more relevant parameters and pointed out to several applications, among them controlled work hardening and plastic anisotropy measurement. Combining a nearly cyclic bending deformation path with a steady-state drawing promotes very high levels of effective strain and stress, even without apparent macrostrains. The numerical simulation of bend/drawing forecasts that deformation ratio ε 2/ ε 3 on the strip is related to the Lankford anisotropy plastic coefficient measured by the uniaxial tensile test. Experimental measurements confirm this trend, pointing out to a new method to estimate Lankford coefficients.

Control, automation and the hot rolling of steel

Restricted accessMoreSectionsView PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Cite this article Reeve P.J., MacAlister A.F. and Bilkhu T.S. 1999Control, automation and the hot rolling of steelPhil. Trans. R. Soc. A.3571549–1571http://doi.org/10.1098/rsta.1999.0389SectionRestricted accessControl, automation and the hot rolling of steel P.J. Reeve P.J. Reeve ALSTOM Drives & Controls Ltd†, Boughton Road, Rugby CV21 1BU, UK Google Scholar Find this author on PubMed Search for more papers by this author , A.F. MacAlister A.F. MacAlister ALSTOM Drives & Controls Ltd†, Boughton Road, Rugby CV21 1BU, UK Google Scholar Find this author on PubMed Search for more papers by this author and T.S. Bilkhu T.S. Bilkhu ALSTOM Drives & Controls Ltd†, Boughton Road, Rugby CV21 1BU, UK Google Scholar Find this author on PubMed Search for more papers by this author P.J. Reeve P.J. Reeve ALSTOM Drives & Controls Ltd†, Boughton Road, Rugby CV21 1BU, UK Google Scholar Find this author on PubMed Search for more papers by this author , A.F. MacAlister A.F. MacAlister ALSTOM Drives & Controls Ltd†, Boughton Road, Rugby CV21 1BU, UK Google Scholar Find this author on PubMed Search for more papers by this author and T.S. Bilkhu T.S. Bilkhu ALSTOM Drives & Controls Ltd†, Boughton Road, Rugby CV21 1BU, UK Google Scholar Find this author on PubMed Search for more papers by this author Published:15 June 1999https://doi.org/10.1098/rsta.1999.0389AbstractThe current state of automation and control for hot rolling mills, with a particular emphasis on flat products, is introduced. A typical modern control–system design is discussed together with the impact on the design of process models, available measurements, available control actuators and material properties. Both the piece–to–piece mill control calculations and in–piece dynamic control are covered. Currently, control of microstructure is achieved by imposing deformation and temperature time profiles on the process. The need for ever more stringent product quality will lead to the demand for a tighter control of microstructure. How might microstructure modelling and process control affect each other in achieving this? Some ideas are introduced and discussed. Previous ArticleNext Article VIEW FULL TEXT DOWNLOAD PDF FiguresRelatedReferencesDetailsCited by Zhang F, Zong S and Ling Z (2017) Fault diagnosis using kernel principal component analysis for hot strip mill, The Journal of Engineering, 10.1049/joe.2017.0190, 2017:9, (527-535), Online publication date: 1-Sep-2017. Zhang F, Wang X, Zong S and Xiang X (2016) Research and application of computer control system for aluminium single‐stand 4‐high cold rolling mill, The Journal of Engineering, 10.1049/joe.2016.0182, 2016:11, (415-422), Online publication date: 1-Nov-2016. Zhang F, Zong S, Wang X and Ren X (2016) An Expert PI Controller with Dead Time Compensation of Monitor AGC in Hot Strip Mill, Mathematical Problems in Engineering, 10.1155/2016/3041538, 2016, (1-8), . Jáuregui A, Guerrero-Mata M, Monsalve A, Artigas A, Leduc L and Colás R (2013) Plastic deformation of low carbon steels, International Heat Treatment and Surface Engineering, 10.1179/1749514812Z.00000000041, 6:4, (164-167), Online publication date: 1-Dec-2012. dos Santos Filho A and Ramirez-Fernandez F (2010) Neural networks to improve mathematical model adaptation in the flat steel cold rolling process 2010 International Joint Conference on Neural Networks (IJCNN), 10.1109/IJCNN.2010.5596794, 978-1-4244-6916-1, (1-7) (2010) Oxide Scale and Through-Process Characterization of Frictional Conditions for the Hot Rolling of Steel: Industrial Input Oxide Scale Behavior in High Temperature Metal Processing, 10.1002/9783527630318.ch9, (271-366) This Issue15 June 1999Volume 357Issue 1756Discussion Meeting Issue ‘Deformation processing of metals’ organized by M. F. Ashby, F. J. Humphreys, C. M. Sellars, H. R. Shercliff and M. J. Stowell Article InformationDOI:https://doi.org/10.1098/rsta.1999.0389Published by:Royal SocietyPrint ISSN:1364-503XOnline ISSN:1471-2962History: Published online15/06/1999Published in print15/06/1999 License: Citations and impact Keywordsmodel adaptionfeedback controltandem rolling millsfeedforward controlrolling mill models

The deformation models needed by the steel industry

Restricted accessMoreSectionsView PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Cite this article Melton K.N. 1999The deformation models needed by the steel industryPhil. Trans. R. Soc. A.3571531–1547http://doi.org/10.1098/rsta.1999.0388SectionRestricted accessThe deformation models needed by the steel industry K.N. Melton K.N. Melton British Steel, Swinden Technology Centre, Moorgate, Rotherham S60 3AR, UK Google Scholar Find this author on PubMed Search for more papers by this author K.N. Melton K.N. Melton British Steel, Swinden Technology Centre, Moorgate, Rotherham S60 3AR, UK Google Scholar Find this author on PubMed Search for more papers by this author Published:15 June 1999https://doi.org/10.1098/rsta.1999.0388AbstractThe steel supply chain generally comprises a steel producer, manufacturing semi–finished products, and a steel user, manufacturing formed components. A review is presented of the deformation models needed by the steel industry, considering the current and expected future requirements of the end users. A trend that is expected to accelerate is their increased use of automation. This imposes a tighter dimensional tolerance, which requires, among other things, models that predict rolling loads and physically based models being introduced, offering distinctive benefits that will be discussed. A narrow distribution of mechanical properties is needed, requiring techniques that link deformation parameters such as strain, time and temperature, through microstructure models to property prediction, and this should include toughness as well as yield strength. Being able to predict toughness at all points in a rolled product would significantly reduce waste and costs associated with destructive testing. The need for lightweight designs is leading to wider application of high–strength steels. Because of the requirements of lower cost and good weldability, the high strengths are being achieved through leaner chemistries, using controlled thermomechanical processing, where the transformation from austenite needs to be incorporated into the models. This is a major difference between steel and aluminium. Laser fabrication techniques are increasingly being used; these require high degrees of flatness in the steel, including after it has been cut, where non–uniform residual stress distribution can lead to distortion. Models that predict residual stresses are needed, and, since the customer might buy the steel in a coil and uncoil it himself, the residual stress model and data will need to be shared. Customers will become more than recipients of steel; they will share in the knowledge embedded in the steel, and the ability to do this, along the varying deformation processes used by the steel industry, is a challenge for those developing the modelling techniques. Previous ArticleNext Article VIEW FULL TEXT DOWNLOAD PDF FiguresRelatedReferencesDetailsCited by (2017) References Recrystallization and Related Annealing Phenomena, 10.1016/B978-0-08-098235-9.16001-X, (647-681), . Jáuregui A, Guerrero-Mata M, Monsalve A, Artigas A, Leduc L and Colás R (2013) Plastic deformation of low carbon steels, International Heat Treatment and Surface Engineering, 10.1179/1749514812Z.00000000041, 6:4, (164-167), Online publication date: 1-Dec-2012. (2004) References Recrystallization and Related Annealing Phenomena, 10.1016/B978-008044164-1/50023-2, (557-615), . Hurley P and Humphreys F (2003) Modelling the recrystallization of single-phase aluminium, Acta Materialia, 10.1016/S1359-6454(03)00192-7, 51:13, (3779-3793), Online publication date: 1-Aug-2003. Grong Ø and Shercliff H (2002) Microstructural modelling in metals processing, Progress in Materials Science, 10.1016/S0079-6425(00)00004-9, 47:2, (163-282), . Myhr O (2001) Modelling of the age hardening behaviour of Al–Mg–Si alloys, Acta Materialia, 10.1016/S1359-6454(00)00301-3, 49:1, (65-75), Online publication date: 1-Jan-2001. This Issue15 June 1999Volume 357Issue 1756Discussion Meeting Issue ‘Deformation processing of metals’ organized by M. F. Ashby, F. J. Humphreys, C. M. Sellars, H. R. Shercliff and M. J. Stowell Article InformationDOI:https://doi.org/10.1098/rsta.1999.0388Published by:Royal SocietyPrint ISSN:1364-503XOnline ISSN:1471-2962History: Published online15/06/1999Published in print15/06/1999 License: Citations and impact Keywordsthrough–process modelsteelhot rollingprocess controlfinite elementdeformation modelling

Introduction to Deformation processing of metals. A Discussion Meeting held at the Royal Society on 21 and 22 October 1998

Introduction to Deformation processing of metals. A Discussion Meeting held at the Royal Society on 21 and 22 October 1998. Organized and edited by M. F. Ashby, F. J. Humphreys, C. M. Sellars, H. R. Shercliff and M. J. Stowell.The control of microstructures and textures during the deformation and annealing of alloys is of great importance and has been of wide scientific interest for many years. Our understanding, however, of the plastic deformation of metals is far from complete and this is now recognized as an important limitation in developing the quantitative models for thermomechanical processing that are required by the metals industries. The development of new methods of modelling and new techniques for characterization of microstructure and texture are having an impact in this field, and it was therefore timely to hold a Discussion Meeting on deformation processing.

Using high performance Fortran for parallel programming

A finite element code with a polycrystal plasticity model for simulating deformation processing of metals has been developed for parallel computers using High Performance Fortran (HPF). The conversion of the code from an original implementation on the Connection Machine systems using CM Fortran is described. The sections of the code requiring minimal inter-processor communication are easily parallelized, by changing only the syntax for specifying data layout. However, the solver routine based on the conjugate gradient method required additional modifications, which are discussed in detail. The performance of the code on a massively parallel distributed-memory Intel PARAGON supercomputer is evaluated through timing statistics. Published by Elsevier Science Ltd.

Enhanced boundary lubrication by potential control during copper wire drawing

Metal deformation process, such as wire drawing, is conventionally performed under open-circuit conditions. Lubrication is heavily dependent on the surface conditions of the wire. The surface condition of the wire depends on the electrochemical reactions once the wire contacts with the emulsion lubricant. An oxide layer on the incoming wire could be removed partially or completely and repassivation occurs on the asperities of the wire after abrasion. Adsorption of fatty acid on the oxide layer of the wire could play a vital part in the efficiency of boundary lubrication. Friction could be reduced when a proper potential is applied between the wire and the auxiliary tube before the drawing dies. The reduction of friction detected at various potentials depended on the lubricant chemical composition. Surface quality could be significantly improbed and energy consumption substantially reduced by the potential control.

Optimization of microstructure development: application to hot metal extrusion

A new process design method for controlling microstructure development during hot metal deformation processes is presented. This approach is based on modern control theory and involves state-space models for describing the material behavior and the mechanics of the process. The challenge of effectively controlling the values and distribution of important microstructural features can now be systematically formulated and solved in terms of an optimal control problem. This method has been applied to the optimization of grain size and certain process parameters such as die geometry profile and ram velocity during extrusion of plain carbon steel. Various case studies have been investigated, and experimental results show good agreement with those predicted in the design stage.

Aggregate size effect on the predicted plastic response of hexagonal close-packed polycrystals

The effect of aggregate size (number of crystals per aggregate) on texture development and mechanical response of hexagonal close-packed (HCP) polycrystals has been studied numerically. The single crystal deforms only by basal and prismatic slip, and, hence, has an inextensible hexagonal direction (c-axis). The polycrystal is modeled using the hybrid approach developed by Parks and Azhi, where a fourth-order projection tensor depending on the average of the c-axis orientation plays a key role in the formulation. In this model, the deformation applied to the crystals of the aggregate is determined by this projection tensor, which depends on aggregate size, and the imposed macroscopic deformation. The dependence of the average projection tensor on aggregate size is studied by simulating plane strain compression tests on aggregates of different size comprised of inextensible HCP crystals. Both material point and finite element simulations are used. Numerical results show that (i) the average projection tensor is very sensitive to aggregate size, resulting in predictions of sharper texture and stronger hardening for smaller aggregates, and (ii) the spatially non-uniform deformation among aggregates within a finite element discretization increases as the aggregate size is reduced, tending to diffuse texture. Based on this study, a minimum number of 250 crystals per aggregate is suggested to minimize the aggregate size effect in numerical simulations of large-scale HCP metal deformation processes using Parks and Azhi's hybrid model.

Activation energy spectra for stress-induced ordering in amorphous materials calculated using Fourier techniques

A method for calculating the activation energy spectrum from isothermal data using Fourier techniques is used for studying the deformation processes in amorphous metals. The influence of experimental error on the calculated spectrum is discussed. The activation energy spectrum derived from the anelastic deformation of Fe40Ni40B20 amorphous metallic ribbon is presented. The spectrum obtained involves three well-separated peaks, each of which represents a different material transport mechanism.

The 15th International Symposium on the physics of metals ?Numerical simulation of deformation processes in metals?

The 15th International Symposium on the physics of metals ?Numerical simulation of deformation processes in metals?

Use of crystal plasticity in metal forming simulations

Some recent work on the implementation of crystal plasticity constitutive relations in the simulation of metal deformation processes is discussed. The rate-dependent crystal plasticity theory employed is first briefly presented. We then consider some special cases of fcc metals with certain “ideal textures”, for which closed-form analytical solutions are given for rolling and biaxial sheet stretching modes. Finally, the incorporation of the crystal plasticity constitutive relations into the finite element analysis of large-strain boundary-value problems is illustrated. The example treated is the behaviour of axially constrained and freely elongating solid circular bars subject to finite strain torsion.

Low-temperature abrupt deformation processes in metals: kinetic and statistical properties observed by means of electronic response

The properties of abrupt plastic deformation occurring in Nb and Al at low temperature were investigated using electronic response signal measurements. Statistical treatment of the results led to the possible conclusion that a self-organized criticality in the system of plastic carriers leads to the abrupt movement.

Stochastic Modelling of Cyclic Deformation Processes in Metals

Stochastic Modelling of Cyclic Deformation Processes in Metals

The Mechanism of Influence of Non‐Octahedral Slip on RollingTexture Development in FCC Metals. Computer Simulation

Simulation of the copper‐type rolling texture development in FCC metals based on homogeneous slip under conditions of no constrains (Sachs‐type model) is presented. Detailed analysis shows that, in fact, effective activation of a few (two or three, sometimes greater) independent slip systems occurs after reaching of some strain. These slip systems act by turns and may be essentially considered as acting simultaneously. Therefore, such extended description may be considered as a model which is intermediate between Taylor and Sachs ones. Taking these results into account, the characteristic features of main texture component development in copper under rolling have been studied by a computer simulation. Both octahedral, {111}, and cubic, {100}, slip planes are shown to act simultaneously in the process of the {112} component formation, but the action of only {111} slip systems is characteristic for the {110} component formation. The important role of the non‐octahedral sip systems in plastic deformation processes in FCC metals of high staking‐fault energy are also confirmed by the coincidence of model shear textures and experimental surface textures.

An approximate procedure for predicting the evolution of crystallographic texture in bulk deformation processing of fcc metals

An approximate procedure for predicting the evolution of crystallographic texture during bulk deformation processing of fcc materials is proposed. The two steps in the proposed procedure are: (1) extract the history of the local deformation gradient in the neighborhood of a material point of interest with a finite element calculation using an isotropic plasticity model; (2) use this deformation gradient history in a separate Taylor-type polycrystal model calculation outside the finite element procedure, to predict the evolution of crystallographic texture at the material point of interest. Using this approximate but quicker procedure we have simulated two different plane-strain forgings of initially isotropic OFHC copper, and evaluated the accuracy of the procedure by comparing predictions for the overall load-displacement curves and texture evolution against corresponding experimental results. The two-step approximate procedure is shown to work well for the high-symmetry fcc copper formed in closed dies.

Crystallographic texture evolution in bulk deformation processing of FCC metals

A Taylor-type polycrystalline model, together with a new fully-implicit time-integration scheme has been developed and implemented in a finite element program to simulate the evolution of crystallographic texture during bulk deformation processing of face centered cubic metals deforming by crystallographic slip. The constitutive equations include a new equation for the evolution of slip system deformation resistance which leads to macroscopic strain hardening behavior that is in good accord with experiments performed on OFHC copper. The good predictive capabilities of the constitutive equations and the time-integration procedure for simulating the stress-strain behavior and the evolution of texture under both homogeneous and non-homogeneous deformation conditions are demonstrated by comparing numerical simulations against experimental measurements in simple shear and a simple plane-strain forging experiment on copper.

The reactions of oxidised aluminium surfaces with lubricant additives and related compounds

To improve the understanding of the role of lubricants in metal deformation processes, FABSIMS (fast atom bombardment secondary ion mass spectroscopy) and RAIRS (reflection absorption infrared spectroscopy) were used to study the chemical interaction of carboxylic acids on oxidised aluminium surfaces. Both techniques detected acid anions, so were consistent with the chemisorption of the acid molecules on the surface. In addition, high mass fragments were detected in the FABSIMS spectra that are associated with oxide clusters and appear to be characteristic of the adsorbed state of the organic acid on the surface. Results from FABSIMS analysis of a sample from a hot rolling mill indicate that similar types of reaction occur in the rolling process.