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The Cyclic Deformation Behavior of Severe Plastic Deformation (SPD) Metals and the Influential Factors  [PDF]
Charles C. F. Kwan,Zhirui Wang
Metals , 2012, DOI: 10.3390/met2010041
Abstract: A deeper understanding of the mechanical behavior of ultra-fine (UF) and nanocrystalline (NC) grained metals is necessary with the growing interest in using UF and NC grained metals for structural applications. The cyclic deformation response and behavior of UF and NC grained metals is one aspect that has been gaining momentum as a major research topic for the past ten years. Severe Plastic Deformation (SPD) materials are often in the spotlight for cyclic deformation studies as they are usually in the form of bulk work pieces and have UF and NC grains. Some well known techniques in the category of SPD processing are High Pressure Torsion (HPT), Equal Channel Angular Pressing (ECAP), and Accumulative Roll-Bonding (ARB). In this report, the literature on the cyclic deformation response and behavior of SPDed metals will be reviewed. The cyclic response of such materials is found to range from cyclic hardening to cyclic softening depending on various factors. Specifically, for SPDed UF grained metals, their behavior has often been associated with the observation of grain coarsening during cycling. Consequently, the many factors that affect the cyclic deformation response of SPDed metals can be summarized into three major aspects: (1) the microstructure stability; (2) the limitation of the cyclic lifespan; and lastly (3) the imposed plastic strain amplitude.
Investigations of Self-Healing Property of Chitosan-Reinforced Epoxy Dye Composite Coatings  [PDF]
Hüsnügül Y?lmaz Atay,Leyla Eral Do?an,Erdal ?elik
Journal of Materials , 2013, DOI: 10.1155/2013/613717
Abstract: Chitosan has a very wide application range in different parts of life such as in biomedical and antimicrobial areas. In recent years the self-healing property of chitosan becomes more of an issue. In the study chitosan was used to obtain a self-healing composite material. An epoxy dye was converted to a self-healing coating. Different types of samples were prepared by coating the glass substrates with a polymer matrix reinforced with various amounts of chitosan. The samples were characterized by fourier transform Infrared (FTIR) and scanning electron microscope-energy dispersive spectroscopy (SEM-EDS). In addition, self-healing test was applied as a primary objective of this research. In this respect, the samples were scratched with a very thin pin, and they were analyzed by SEM periodically. It was observed that chitosan-reinforced dyes showed self-healing property. Mechanism of the self-healing process was also scrutinized. 1. Introduction A self-healing material is a material that has the built-in ability to partially repair damage occurring during its service life time. Self-healing is the ability of a material to restore mechanical properties, which were earlier perturbed by a plastic deformation or failure involving cracks and voids. Usually, certain properties of any engineering material such as metals, polymers, ceramics, cementitious, and elastomeric and fibre-reinforced composite materials degrade over time due to environmental conditions or fatigue or due to damage incurred during operation. This damage is often on a microscopic scale, requiring periodic inspection and repair to avoid them growing and causing failure [1]. Self-healing materials address this degradation through the inclusion of an “active” phase that responds to the microdamage by initiating a repair mechanism, and several mechanisms have been proposed for the engineering materials. Investigation of possible self-healing mechanisms is an important emerging field of nanotechnology [2]. The inspiration of self-healing materials comes from biological systems, which have the ability to heal after being wounded. Initiation of cracks or other types of damage on a microscopic level changed thermal, electrical, and acoustical properties and eventually led to whole scale failure of the material. Usually, cracks cannot be mended by hand because it is hard/difficult to detected. A material that can intrinsically correct damage can lower production costs of a number of different industrial processes, can reduce the inefficiency over time caused by degradation, and can prevent costs
Role of Edge and Screw Dislocations in Composite System on the Plastic Deformation of Metals
Jian JIANG,Chiwei LUNG,

材料科学技术学报 , 1996,
Abstract: The present paper has studied the effects of dislocation density on the role of edge and screwdislocations and described further the parallel feature of the edge and screw dislocations andtheir role on the plastic deformation of metals.
STRUCTURE AND PHYSICAL PROPERTIES OF SUBMICROCRYSTALLINE METALS PREPARED BY SEVERE PLASTIC DEFORMATION
R R Mulyukov,M D Starostenkov Institute for Metals Superplasticity Problems of Russian Academy of Sciences,Khalturina,Ufa,Russia Altai State Technical University,
R.
,R.,Mulyukov,and,M.,D.,Starostenkov

金属学报(英文版) , 2000,
Abstract: The results of investigations of structure and physical properties of submicrocrystalline (SMC) metals are presented. The SMC structure was formed by severe plastic deformation.The structure was investi- gated by calorimetric and mossbauer measurements and TEW stuidies. The behavior of physical proper- ties of SMC metals were analysed taking into account spectific features of their structure.
Unusual plastic deformation and damage features in Titanium: experimental tests and constitutive modeling  [PDF]
Benoit Revil-Baudard,Oana Cazacu,Philip Flater,Nitin Chandola,J. L. Alves
Physics , 2015,
Abstract: In this paper, we present an experimental study on plastic deformation and damage of polycrystalline pure Ti, as well as modeling of the observed behavior. From the mechanical characterization data, it can be concluded that the material displays anisotropy and tension-compression asymmetry. As concerns damage, the X-ray tomography measurements conducted reveal that damage distribution and evolution in this HCP Ti material is markedly different than in a typical FCC material such as copper. Stewart and Cazacu (2011) anisotropic elastic/plastic damage model is used to describe the behavior. All material parameters involved in this model have a clear physical significance, being related to plastic properties, and are determined based on very few simple mechanical tests. It is shown that this model predicts correctly the anisotropy in plastic deformation, and its strong influence on damage distribution and damage accumulation in Ti. Specifically, for a smooth axisymmetric specimen subject to uniaxial tension, damage initiates at the center of the specimen and is diffuse; the level of damage close to failure is very low. On the other hand, for a notched specimen subject to the same loading, the model predicts that damage initiates at the outer surface of the specimen, and further grows from the outer surface to the center of the specimen, which corroborates with the in-situ tomography data.
THE WORK HARDENING OF METALS IN INDUSTRIAL PROCESSES OF PLASTIC DEFORMATION
W TRUSZKOWSKI Institute of Metals,Polish Academy of Sciences,
W.TRUSZKOWSKI

金属学报 , 1959,
Abstract: If a plastic metal is subjected to permanent deformation, then due to the changesoccurring in crystallographic lattice the metal alters its properties. Experiments carried outby many investigators prove that the ultimate strength, the yield strength and hardness in-crease with the deformation, on the other hand, the elongation decreases, the impact valueand reduction of area also change. Fig. 1 illustrates the effect of cold work by drawingon the mechanical properties of an armco iron according to W. Broniewski and J. Krol.
HOT DEFORMATION BEHAVIOUR OF Nb-BEARING LOW CARBON STEEL AND PREDICTION OF FLOW STRESS FOR METALS DURING PLASTIC DEFORMATION
GAO WeilinBAI Guangrun,ZHOU Zhimin,LUAN Guifu Northeast University of TechnologyShenyang,ChinaLONG Chunman Anshan Iron,Steel Company,China Lecturer,Post Box NoNortheast University of TechnologyShenyang,China,
GAO Weilin.BAI Guangrun
,ZHOU Zhimin,LUAN Guifu Northeast University of Technology.Shenyang,China LONG Chunman Anshan Iron and Steel Company,China Lecturer,Post Box No..Northeast University of Technology.Shenyang,China

金属学报(英文版) , 1993,
Abstract: Experimental investigation of hot deformation behaviour of Nb-bearing low carbon steel 14MnNb was carried out by Gleeble 1500 simulator.Regressive analysis was made of the re- lationship between deformation onditions and steady state flow stress during hot deformation and the peak fliw stress corresponding to dynamic recrystallization.Clarification was also described for the influence of strain-induced Nb(C.N)precipitation on the activation energy of deformation.On the basis of analyzing the processes of dislocation multiplication and re- coveries from cross-slip of screw dislocation and from climb of edge dislocation during plastic deformation of metals.the theoretical mpdel to predict flow stress under the condiltions of dy- namic recorery and recrystallization occirred simultancously was developed,The prediction about flow stress in practice,under various deformation conditions by the model seems in fair agreement with the experimental results.
Dynamic Plastic Deformation (DPD): A Novel Technique for Synthesizing Bulk Nanostructured Metals
Dynamic Plastic Deformation (DPD): A Novel Technique for Synthesizing Bulk Nanostructured Metals

Nairong TAO,Ke LU,
Nairong
,TAO,Ke,LU

材料科学技术学报 , 2007,
Abstract: While some superior properties of nanostructured materials (with structural scales below 100 nm) have attracted numerous interests of material scientists, technique development for synthesizing nanostructured metals and alloys in 3-dimensional (3D) bulk forms is still challenging despite of extensive investigations over decades.Here we report a novel synthesis technique for bulk nanostructured metals based on plastic deformation at high Zener-Hollomon parameters (high strain rates or low temperatures), i.e., dynamic plastic deformation (DPD).The basic concept behind this approach will be addressed together with a few examples to demonstrate the capability and characteristics of this method. Perspectives and future developments of this technique will be highlighted.
ПРОГНОЗИРОВАНИЕ РАЗРУШЕНИЯ МЕТАЛЛА В ПРОЦЕССЕ ИНТЕНСИВНОЙ ПЛАСТИЧЕСКОЙ ДЕФОРМАЦИИ ДЛИННОМЕРНОЙ ЗАГОТОВКИ РАВНОКАНАЛЬНЫМ УГЛОВЫМ ПРЕССОВАНИЕМ КОНФОРМ Metal damage prediction during severe plastic deformation of long-length billets by equal channel angular pressing “Conform”  [cached]
А. В. Боткин,Р. З. Валиев,Г. И. Рааб,А. А. Кубликова
Vestnik UGATU , 2012,
Abstract: Приведена методика определения рациональных термических и механических условий деформации длинномерной заготовки равноканальным угловым прессованием по схеме Конформ для получения УМЗ структуры металла с приемлемой деформационной поврежденностью. Показано хорошее согласование результатов определения термических и механических условий деформации металла и данных физического эксперимента. The technique of determination of rational thermal and mechanical conditions for deformation of longlength billets by equal-channel angular pressing “Conform” is described for producing of ultra fine grade structure in metals with acceptable deformational damage. Good agreement of metal damage prediction results and physical experiment data is shown.
Special Deformation Structures During Machining Plastic Metals, Their Activation And Use
Karol Vasilko
International Journal of Engineering and Advanced Technology , 2012,
Abstract: The contribution analyses the possibilities ofmodification of cutting geometry in order to preservea protective plastic zone of a material upon a cutting key.Based on the results of model experiment as well as practicalverification, considerable increase in tool life has beenachieved. The tools durability is dependent on the size of theshortened front face. Optimation of the face size enables toachieve a multiple durability when compared to a classicalcutting key. The peculiarity of the processes is the creation ofthe two chips, one of which is an expelled plastic layer alongthe edge of the cutting tool. The application of the tool ispossible only with the plastic materials cutting. Experimentaltests have been carried out with frequently used steels. cuttingtool, plastic deformation, wear, hips
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