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Improvement in the mechanical properties of Al/SiC nanocomposites fabricated by severe plastic deformation and friction stir processing  [PDF]
M. Sarkari Khorrami,M. Kazeminezhad,Y. Miyashita,A. H. Kokabi
- , 2017, DOI: https://doi.org/10.1007/s12613-017-1408-3
Abstract: Severely deformed aluminum sheets were processed by friction stir processing (FSP) with SiC nanoparticles under different conditions to improve the mechanical properties of both the stir zone and the heat affected zone (HAZ). In the case of using a simple probe and the same rotational direction (RD) of the FSP tool between passes, at least three FSP passes were required to obtain the appropriate distribution of nanoparticles. However, after three FSP passes, fracture occurred outward from the stir zone during transverse tensile tests; thus, the strength of the specimen was significantly lower than that of the severely deformed base material because of the softening phenomenon in the HAZ. To improve the mechanical properties of the HAZ, we investigated the possibility of achieving an appropriate distribution of nanoparticles using fewer FSP passes. The results indicated that using the threaded probe and changing the RD of the FSP tool between the passes effectively shattered the clusters of nanoparticles and led to an acceptable distribution of SiC nanoparticles after two FSP passes. In these cases, fracture occurred at the HAZ with higher strength compared to the specimen processed using three FSP passes with the same RD between the passes and with the simple probe. The fracture behaviors of the processed specimens are discussed in detail.
ZHAO Xiang,LIU Yansheng,XU Jiazhen,LIANG ZhideNortheastern University,Shenyang,ChinaKONG Bingyu,MI XiaochuanBaoshan Iron,Steel Company,Shanghai,China,
ZHAO Xiang
,LIU Yansheng,XU Jiazhen,LIANG ZhideNortheastern University,Shenyang,ChinaKONG Bingyu,MI XiaochuanBaoshan Iron and Steel Company,Shanghai,China

金属学报(英文版) , 1994,
Abstract: Two improvements have been made on the calculation of plastic strain ratio (r value) in BCC monocrystals by considering the differences in the critical shear stresses among the three slip systems and the rotation of crystal lattice. It is found that the results calculated by the improved method are more rational.
Mechanical Properties of Plastic Concrete Containing Bentonite  [cached]
Peng Zhang,Qiaoyan Guan,Qingfu Li
Research Journal of Applied Sciences, Engineering and Technology , 2013,
Abstract: Plastic concrete consists of aggregates, cement, water and bentonite, mixed at a high water cement ratio, to produce a ductile material. It is used for creating an impermeable barrier (cut-off wall) for containment of contaminated sites or seepage control in highly permeable dam foundations. The effects of water to binder ratio and clay dosage on mechanical properties of plastic concrete were investigated. The results indicate that the water to binder ratio and clay dosage have great influence on the mechanical properties of plastic concrete. There is a tendency of decrease in the compressive strength, splitting tensile strength, shear strength and elastic modulus of plastic concrete with the increase of water to binder ratio and clay dosage, while, the internal friction angle of the shear specimens is increasing gradually. To improve the resistance to deformation of cut-off walls constructed with plastic concrete, the higher water to binder ratio and clay dosage can be selected to decrease the elastic modulus of plastic concrete in the practical design and applications of plastic concrete on condition that the plastic concrete has enough compressive strength, tensile strength and shear strength.
Atomistic Simulations of Elastic and Plastic Properties in Amorphous Silicon  [PDF]
Mina Talati,Tristan Albaret,Anne Tanguy
Physics , 2008, DOI: 10.1209/0295-5075/86/66005
Abstract: We present here potential dependent mechanical properties of amorphous silicon studied through molecular dynamics (MD) at low temperature. On average, the localization of elementary plastic events and the co-ordination defect-sites appears to be correlated. For Tersoff potential and SW potential the plastic events centered on defects-sites prefer 5-fold defect sites, while for modified Stillinger-Weber potential such plastic events choose 3-fold defect sites. We also analyze the non-affine displacement field in amorphous silicon obtained for different shear regime. The non-affine displacement field localizes when plastic events occur and shows elementary shear band formation at higher shear strains.
Clinical characteristics and properties of plastic brackets: A comprehensive review.  [PDF]
A. Karamouzos,A.E. Athanasiou,M.A. Papadopoulos
Hellenic Orthodontic Review , 1998,
Abstract: Aim of this article is to provide the clinician with an up-to-date comprehensive literature review concerning the clinical characteristics and properties of plastic brackets. The article criticaily presents and discusses the various aspects of plastic brackets with regard to the construction, material properties, bond strength, frictional resistance, torque properties and bracket fracture. The article also contains guidelines and criteria concerning-the specific applications and use of plastic brackets.
Plastic properties of cold-deformed ironbased sintered materials  [PDF]
K. Zar?bski,S. Okoński,P. Putyra,A. Tabor
Archives of Foundry Engineering , 2010,
Abstract: Cold plastic forming of sintered metal powders has limited practical application because of, among others, the deformation degree andinitial porosity of preforms. Cold forming is combined with a very drastic drop of plastic properties observed in final products. One of the methods that enable regaining the lost plasticity is annealing of sinters after deformation at temperatures above the recrystallisation point. The results of the investigations were presented which aimed at the determination of an effect that the annealing conditions of colddeformed sintered metal powder can have on its structure and mechanical properties. Special attention was drawn to a combined effect of the deformation degree and heat treatment temperature on final plastic properties of the sinters and on their ultimate tensile strength.
Investigation Of HDPE Plastic Waste Aggregate On The Properties Of Concrete  [cached]
A. M. Mustafa Al Bakri,S. Mohammad Tamizi,A. R. Rafiza,Y. Zarina
Journal of Asian Scientific Research , 2011,
Abstract: Quantities of polymer wastes have increased in recent years due to increases inindustrialization and the rapid improvement in the standard of living. In Malaysia,most polymer wastes are abandoned and not recycled, causing serious problems, suchas the waste of natural resources and environmental pollution. Polymer products, suchas synthetic fibers, plastics, and rubber, are made from petrochemical compounds, andthey degrade extremely slowly in the natural environment. Plastic materials are noteasily biodegradable even after a long period. In fact, a wide variety of waste materialscan be utilized as inert materials in the cement matrix. In this research, trash bagplastics were used as the polymer waste types high-density polyethylene (HDPE) forpreparation of polymer concrete (PC). The aim of this work was to study the propertiesof polymer HDPE and to characterize this polymer as a potential replacement forcoarse aggregate in concrete. Heating was conducted at five different temperatures,i.e., 160 °C, 170 °C, 180 °C, 190 °C, and 200°C. Five compositions of coarseaggregate with different crushed stone: HDPE waste volumetric ratios were used, i.e.,0:100, 15:85, 30:70, 45:55, and 60:40. Comparisons of conventional concrete withpolymer waste as coarse aggregate were conducted. The effects of polymer wastes onthe workability and strength of the concrete with fresh and hardened concrete testswere analyzed. Compressive strength was measured after 28 days, and it was foundthat the PC was suitable for non-structural usage. As for the cost analysis, the resultsshowed that the PC was more cost effective than conventional concrete.
Convergence properties of the expected improvement algorithm  [PDF]
Emmanuel Vazquez,Julien Bect
Mathematics , 2007,
Abstract: This paper has been withdrawn from the arXiv. It is now published by Elsevier in the Journal of Statistical Planning and Inference, under the modified title "Convergence properties of the expected improvement algorithm with fixed mean and covariance functions". See http://dx.doi.org/10.1016/j.jspi.2010.04.018 An author-generated post-print version is available from the HAL repository of SUPELEC at http://hal-supelec.archives-ouvertes.fr/hal-00217562 Abstract : "This paper deals with the convergence of the expected improvement algorithm, a popular global optimization algorithm based on a Gaussian process model of the function to be optimized. The first result is that under some mild hypotheses on the covariance function k of the Gaussian process, the expected improvement algorithm produces a dense sequence of evaluation points in the search domain, when the function to be optimized is in the reproducing kernel Hilbert space generated by k. The second result states that the density property also holds for P-almost all continuous functions, where P is the (prior) probability distribution induced by the Gaussian process."
R R Mulyukov,M D Starostenkov Institute for Metals Superplasticity Problems of Russian Academy of Sciences,Khalturina,Ufa,Russia Altai State Technical University,

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.
Influence of severe plastic deformation by the ECAP method on structure and properties of the P2-04BCh steel  [PDF]
M. Greger,V. Vodárek,L. Kander,L. ???ek
Archives of Materials Science and Engineering , 2009,
Abstract: Purpose: Maim aim of this paper is to describe the plastic deformation executed by ECAE of low carbon steel. The ECAE method lead to significant improvement of strength of investigated material.Design/methodology/approach: Experiments were planned and realised an the temperature ranging from room temperature up 280oC. After application of deformation the structure was investigated in dependence on accumulation of deformation and deformation temperature as well as abovementioned final properties.Findings: Accumulated deformation varied from the value 2 to 8. Investigation of structure by electron microscopy was made with use microscope JEOL JEM 2100. Mechanical properties were investigated by tensile test. Statistic evaluation of angular disorientation and of size of grains/sub-grains was also made with use of electron diffraction (EBSD) in combination with scanning electron microscope FEG SEM Philips.Practical implications: The technology ECAE was applied on low carbon steel. It was verification of ECAE application possibility on steel P2-04BCH importantly for following applying on similar kinds of steel, because ECAE deformation influence.Originality/value: The results from his work shall be useful in determining conditions for fabrication of nanocrystalline or sub-microcrystalline steel by the ECAE technology.
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