Cu-Nb Nanocomposite Wires Processed by Severe Plastic Deformation: Effects of the Multi-Scale Microstructure and Internal Stresses on Elastic-Plastic Properties

2012 ◽  
Vol 14 (11) ◽  
pp. 998-1003 ◽  
Author(s):  
Jean-Baptiste Dubois ◽  
Ludovic Thilly ◽  
Pierre-Olivier Renault ◽  
Florence Lecouturier
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Internal Stresses ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Multi Scale

Prediction of the Stress-Strain Response of the Ultrafine-Grained Materials Using Multi-Scale Analysis

2010 ◽  
Author(s):  
Mihaela Banu ◽  
Mitica Afteni ◽  
Alexandru Epureanu ◽  
Valentin Tabacaru
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Aluminum Alloy ◽  
Severe Plastic Deformation ◽  
Scale Analysis ◽  
Multi Scale ◽  
Ultrafine Grained ◽  
Deformation Processes ◽  
Ultrafine Grained Materials ◽  
Multi Scale Analysis

There are several severe plastic deformation processes that transform the material from microsized grains to the nanosized grains under large deformations. The grain size of a macrostructure is generally 300 μm. Following severe plastic deformation it can be reached a grain size of 200 nm and even less up to 50 nm. These structures are called ultrafine grained materials with nanostructured organization of the grains. There are severe plastic deformation processes like equal angular channel, high pressure torsion which lead to a 200 nm grain size, respectively 100 nm grain size. Basically, these processes have a common point namely to act on the original sized material so that an extreme deformation to be produced. The severe plastic deformation processes developed until now are empirically-based and the modeling of them requires more understanding of how the materials deform. The macrostructural material models do not fit the behavior of the nanostructured materials exhibiting simultaneously high strength and ductility. The existent material laws need developments which consider multi-scale analysis. In this context, the present paper presents a laboratory method to obtain ultrafine grains of an aluminum alloy (Al-Mg) that allows the microstructure observations and furthermore the identification of the stress–strain response under loadings. The work is divided into (i) processing of the ultrafine-grained aluminum alloy using a laboratory-scale process named in-plane controlled multidirectional shearing process, (ii) crystallographic analysis of the obtained material structure, (iii) tensile testing of the ultrafine-grained aluminum specimens for obtaining the true stress-strain behavior. Thus, the microscale phenomena are explained with respect to the external loads applied to the aluminum alloy. The proposed multi-scale analysis gives an accurate prediction of the mechanical behavior of the ultrafine-grained materials that can be further applied to finite element modeling of the microforming processes.

scholarly journals OPERATIONAL CONTROL OF THE LIMIT UNIFORM PLASTIC DEFORMATION

2020 ◽  
pp. 33-35
Author(s):  
M. M. Matlin ◽  
V. A. Kazankin ◽  
E. N. Kazankina
Keyword(s):  
Plastic Deformation ◽  
Structural Steels ◽  
Spherical Indenter ◽  
Operational Control ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Acceptable Accuracy ◽  
Plastic Indentation ◽  
Non Destructive

The paper presents a non-destructive method for determining the limit uniform narrowing of structural steels by the parameters of the elastic-plastic indentation of a spherical indenter. An acceptable accuracy of the method for engineering assessment of the plastic properties of the material of parts is shown.

scholarly journals Влияние равноканального углового прессования и гидростатического давления на упругие и микропластические свойства сплава Cu-0.2 wt.% Zr

2019 ◽  
Vol 89 (10) ◽  
pp. 1563
Author(s):  
Б.К. Кардашев ◽  
В.И. Бетехтин ◽  
М.В. Нарыкова ◽  
А.Г. Кадомцев ◽  
О.В. Амосова
Keyword(s):  
Plastic Deformation ◽  
Hydrostatic Pressure ◽  
Severe Plastic Deformation ◽  
Equal Channel Angular Pressing ◽  
High Hydrostatic Pressure ◽  
Plastic Properties ◽  
Angular Pressing ◽  
Pressure Application ◽  
Zr Alloy

Studies and analyses of elastic and micro-plastic properties of Cu-0.2 wt%Zr alloy processed by severe plastic deformation and then by high hydrostatic pressure are presented. The effect of nanopores which arise due to equal channel angular pressing and then are healed due to hydrostatic pressure application is estimated.

scholarly journals Structure and Properties of High-Strength Ti Grade 4 Prepared by Severe Plastic Deformation and Subsequent Heat Treatment

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1116
Author(s):  
Alena Michalcová ◽  
Dalibor Vojtěch ◽  
Jaroslav Vavřík ◽  
Kristína Bartha ◽  
Přemysl Beran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Strength ◽  
Ultimate Tensile Stress ◽  
Internal Stresses ◽  
In Situ Xrd ◽  
Microstructure Observation

Severe plastic deformation represented by three passes in Conform SPD and subsequent rotary swaging was applied on Ti grade 4. This process caused extreme strengthening of material, accompanied by reduction of ductility. Mechanical properties of such material were then tuned by a suitable heat treatment. Measurements of in situ electrical resistance, in situ XRD and hardness indicated the appropriate temperature to be 450 °C for the heat treatment required to obtain desired mechanical properties. The optimal duration of annealing was stated to be 3 h. As was verified by neutron diffraction, SEM and TEM microstructure observation, the material underwent recrystallization during this heat treatment. That was documented by changes of the grain shape and evaluation of crystallite size, as well as of the reduction of internal stresses. In annealed state, the yield stress and ultimate tensile stress decreased form 1205 to 871 MPa and 1224 to 950 MPa, respectively, while the ductility increased from 7.8% to 25.1%. This study also shows that mechanical properties of Ti grade 4 processed by continual industrially applicable process (Conform SPD) are comparable with those obtained by ECAP.

Study of the Relationship between Concrete and its Reinforcement Elastic-Plastic Characteristics

2021 ◽  
Vol 1043 ◽  
pp. 109-114
Author(s):  
Violetta Bratoshevskaya
Keyword(s):  
Pore Space ◽  
Crystalline Hydrate ◽  
Internal Stresses ◽  
Material Structure ◽  
Cement Stone ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Adsorption Interaction ◽  
A Charge ◽  
The Relationship

The relationship between the elastic-plastic properties of concrete and its ability to resist the external loads and internal stresses effects arising under the influence of aggressive environmental factors has been studied. In concrete, micro-and macrocracks are filled with air and a liquid phase migrates with periodic environmental temperature, therefore, humidity changes. When the structure is compacted by crystalline hydrate neoplasms arising from supersaturated solutions, their surface increases and, correspondingly the part of water hydraulically bound to it also increases which changes its mobility with temperature. This entire system of interphase and single-phase structural bonds and interactions in concrete changes with fluctuations in humidity, cooling, and especially during phase transitions during freezing. The research found that the introduction of hydraulic additives into the binder, which carry a negative charge on their surface, leads to a charge change of the material structure pore space. The penetration kinetics of aggressive environments, adsorption interaction with the cement stone capillaries surface has been studied.

The Influence of Work Hardening, Internal Stresses, and Stress Relaxation on Ductility of Ultrafine Grained Materials Prepared by Severe Plastic Deformation

2009 ◽  
Vol 633-634 ◽  
pp. 263-272
Author(s):  
David G. Morris ◽  
Maria A. Muñoz-Morris ◽  
Ivan Gutierrez-Urrutia
Keyword(s):  
Plastic Deformation ◽  
Stress Relaxation ◽  
Severe Plastic Deformation ◽  
Work Hardening ◽  
Deformation Behaviour ◽  
High Strength ◽  
Internal Stresses ◽  
Fracture Ductility ◽  
Ultrafine Grained ◽  
Ultrafine Grained Materials

Ultrafine grained materials prepared by methods of severe plastic deformation appear to show good ductility for their high strength. To a large extent this ductility enhancement, for the given strength, is shown to correspond to the fracture ductility and not the uniform ductility at maximum stress. The improved fracture ductility is often due to the refinement or removal of the coarse defects that act as sites for failure nucleation. The low work hardening rate inherent to the very fine microstructures produced by severe plastic deformation essentially condemns such materials to very low uniform ductility. Stress relaxation occurring during unloading after processing, and changes of internal stresses during reloading for mechanical testing, appear to play a significant role in determining deformation behaviour near the onset of plastic flow, and this can affect the measured uniform strain.

Analytical Modeling of Residual Stresses in Burnishing

2010 ◽  
Vol 139-141 ◽  
pp. 921-924
Author(s):  
Jing Zhao ◽  
Wei Xia ◽  
Feng Lei Li ◽  
Zhao Yao Zhou ◽  
Zheng Qiang Tang
Keyword(s):  
Plastic Deformation ◽  
Residual Stresses ◽  
Half Space ◽  
Power Law ◽  
Analytical Modeling ◽  
Normal Force ◽  
Experimental Results ◽  
Concentrated Force ◽  
Plastic Properties ◽  
Elastic Plastic

. An analytical model is developed for the prediction of residual stresses in burnishing. The model is simplified as a concentrated force pressing on elastic-plastic half-space using the solution to the Boussinesq-Flament problem. The treated material admits the elastic-plastic properties with hardening using a power law constitutive relation. Trial computation using Johnson-Cook model on AISI 1042 steel is presented and the results are verified with the experimental results given by Bouzid’s previous work. The residual stresses in the feed direction show the same trend with the experimental results while some differences still exist near the surface because of the concentrated normal force assumption and such stresses increase with the increase of burnishing force, decrease with the increase of depth and turn to zero beyond the plastic deformation boundary.

Effect of Ultrasonic Treatment on the Microstructure and Properties of Nanostructured Nickel Processed by High Pressure Torsion

2010 ◽  
Vol 667-669 ◽  
pp. 605-609 ◽  
Author(s):  
Asiya Nazarova ◽  
Radik R. Mulyukov ◽  
Yuriy Tsarenko ◽  
Vasiliy Rubanik ◽  
Ayrat A. Nazarov
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
High Pressure ◽  
Severe Plastic Deformation ◽  
Grain Growth ◽  
Ultrasonic Treatment ◽  
High Pressure Torsion ◽  
Pure Nickel ◽  
Internal Stresses ◽  
Thermal Stability Of

The effect of ultrasonic treatment on the microstructure, microhardness and thermal stability of pure nickel after high pressure torsion (HPT) was studied. It was shown that the ultrasonic treatment reduces internal stresses induced by severe plastic deformation. The higher the intensity of ultrasound in the range studied, the stronger is this effect. Also it was revealed that grain growth in nickel processed by HPT followed by ultrasonic treatment occurs at higher temperatures than that in nickel as-processed by HPT, i.e. the thermal stability of nanostructured nickel is increased.

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