Structural Changes in the Superficial Layers of a Non-conventional Treated Steel Subjected to a Wear Process

2017 ◽  
Vol 68 (10) ◽  
pp. 2329-2333
Author(s):  
Carmen Penelopi Papadatu ◽  
Andrei Victor Sandu ◽  
Marian Bordei ◽  
Ioan Gabriel Sandu
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Chemical Treatment ◽  
Structural Changes ◽  
Alloyed Steel ◽  
X Ray ◽  
Wear Process ◽  
Treated Steel ◽  
Machinery Building ◽  
Made In

It was considered a non - conventional treatment in magnetic field applied before the thermo-chemical treatment (nitro-carburizing in plasma), for one alloyed steel which is used in Machinery building industry. These researches have been made in order to improve the mechanical properties of Chromium-Molybdenum alloyed steel non-conventionally treated in a magnetic field. Through the thermo-magnetic treatment, applied before the plasma nitro-carburizing, the mechanical properties of this material have been improved, especially in this case of the steel with a considered content of Chromium (1.38%). These researches, through X-Ray diffractometry of the behavior of the superficial layers during the dry wear process, completed this work. The diffractometric characteristics of the superficial layers which have been obtained after a complex system of thermo-magnetic treatments followed by a thermo-chemical treatment, the superficial layers content and the behavior of the steel at the wear through dry friction tests were used as criterion. The paper is a review of the researches from the last few years.

scholarly journals Tribological Evolution of the Superficial Layer and the Effects of the Magnetic Field to a Non- conventional Treated Steel, During Wear Tests

2018 ◽  
Vol 55 (3) ◽  
pp. 442-446
Author(s):  
Carmen Penelopi Papadatu ◽  
Andrei Victor Sandu ◽  
Marian Bordei ◽  
Ioan Gabriel Sandu ◽  
Sorin Ciortan
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Dry Friction ◽  
Experimental Tests ◽  
Superficial Layer ◽  
Alloyed Steel ◽  
Wear Process ◽  
The Magnetic Field ◽  
Wear Tests ◽  
Made In

The article focuses on the behavior of the non-conventional treated alloyed steel in magnetic field, during the dry wear tests. It is a review of the experimental tests from last years. The thermo-magnetic treatments have been applied before the application of a thermo-chemical treatment in plasma based on diffusion process. The study was made in order to improve the mechanical properties of the alloyed steel during the friction wear. Thermo-magnetic treatment applied before the plasma nitro-carburizing treatment improves the mechanical properties of the material especially in this case, for a steel that has a considerable content of Chromium (1.02%). The behavior was studied using X-Ray diffractometry of the superficial layers during the dry friction of wear process. The wear tests used an Amsler machine, during three hours of wear tests. After each hour of the wear tests the samples have been analyzed. The diffractometric characteristics of the superficial layers obtained after a complex array of thermo-magnetic and thermo-chemical in plasma treatments, the phases distribution, the content of the superficial layers and the behavior of the steel during the wear through dry friction tests, have been considered as criteria.

Study on the Influence of the Treatment in Magnetic Field on the Nitrided Layer in Plasma

2017 ◽  
Vol 68 (4) ◽  
pp. 675-679 ◽  
Author(s):  
Carmen Penelopi Papadatu ◽  
Andrei Victor Sandu ◽  
Marian Bordei ◽  
Ioan Gabriel Sandu
Keyword(s):  
Magnetic Field ◽  
Complex System ◽  
Mechanical Properties ◽  
Chemical Treatment ◽  
Dry Friction ◽  
Nitrided Layer ◽  
Alloyed Steel ◽  
Hardness Values ◽  
Made In

These researches have been made in order to improve the mechanical properties of a Chromium�Molybdenum alloyed steel non-conventionally treated in a magnetic field. Through the thermo-magnetic treatments, applied before thermo-chemical treatment, the mechanical properties of this material have been improved, especially in the case of a great content of chromium. The hardness values of the superficial layers which have been obtained after a complex system of thermo-magnetic treatments followed by a thermo-chemical treatment, the superficial layers content and the behaviour of the steel at the wear through dry friction tests were used as criterion. The paper is a review of the researches from the last few years.

Mechanism of the Crystallization of High Polymers

1954 ◽  
Vol 27 (2) ◽  
pp. 374-384 ◽  
Author(s):  
G. Schuur
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Amorphous Material ◽  
Crystalline Polymer ◽  
Longitudinal Direction ◽  
Crystalline Material ◽  
Current View ◽  
X Ray ◽  
Made In ◽  
High Polymers

Abstract The crystallization of higher polymers is a phenomenon which is not yet fully understood, one of the main difficulties being to explain how the spherulites arise. An attempt will be made in this paper to draw a clearer picture of the mechanism of crystallization and thus to account for the origin of spherulites. It will then be seen how several other phenomena involved in the crystallization of natural rubber can be shown to be logically interrelated. The current view is that a crystalline polymer consists of a continuous amorphous phase containing small crystalline regions, the crystallites. The evidence as to the size of these crystallites, however, is at present inconclusive, because only the lower limit of their size can be measured by means of x-ray examination. The reason is that, owing to the absence of reflections of a higher order, the effect of irregularities in the crystallites and of the heat motion of the molecules cannot be measured separately. Another doubtful question is whether the small angle interference maxima are to be interpreted as a measure of mean distances between the crystallites. To do this, Wallner has to resort to the assumption that the crystallites are unstable, whereas it is presumed, on the evidence of the mechanical properties of the high polymers, that a crystallite is stable and permanent. Hoffmann found 82 ± 7 per cent of crystalline material in polychlorotrifluoroethylene and Buckley, Cross, and Ray found as much as 95 per cent in polymethylene. Such high percentages make it doubtful whether the crystalline phase can be discontinuous at all. In this article any volume of material in which the molecules lie parallel is called a crystallite. The direction in which the molecules are oriented is termed the longitudinal direction of the crystallite. It is immaterial to the argument whether a crystallite consists of several crystallites, aligned in parallel separated by a small amount of amorphous material, or of a single crystallite containing large irregularities.

scholarly journals Copper Containing Glass-Based Bone Adhesives for Orthopaedic Applications: Glass Characterization and Advanced Mechanical Evaluation

2020 ◽  
Author(s):  
Sahar. Mokhtari ◽  
Anthony.W. Wren
Keyword(s):  
Mechanical Properties ◽  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Viscoelastic Behavior ◽  
Polymer Chains ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compression Data

AbstractThis study addresses issues with currently used bone adhesives, by producing novel glass based skeletal adhesives through modification of the base glass composition to include copper (Cu) and by characterizing each glass with respect to structural changes. Bioactive glasses have found applications in fields such as orthopedics and dentistry, where they have been utilized for the restoration of bone and teeth. The present work outlines the formation of flexible organic-inorganic polyacrylic acid (PAA) – glass hybrids, commercial forms are known as glass ionomer cements (GICs). Initial stages of this research will involve characterization of the Cu-glasses, significant to evaluate the properties of the resulting adhesives. Scanning electron microscopy (SEM) of annealed Cu glasses indicates the presence of partial crystallization in the glass. The structural analysis of the glass using Raman suggests the formation of CuO nanocrystals on the surface. X-ray diffraction (XRD) pattern and X-ray photoelectron spectroscopy (XPS) further confirmed the formation of crystalline CuO phases on the surface of the annealed Cu-glass. The setting reaction was studied using Fourier transform infrared spectroscopy (ATR-FTIR). The mechanical properties of the Cu containing adhesives exhibited gel viscoelastic behavior and enhanced mechanical properties when compared to the control composition. Compression data indicated the Cu glass adhesives were efficient at energy dissipation due to the reversible interactions between CuO nano particles and PAA polymer chains.

scholarly journals Structural Changes in the Aluminum - Magnesium System Alloy

2020 ◽  
Vol 989 ◽  
pp. 577-582
Author(s):  
I.E. Illarionov ◽  
T.R. Gilmanshina ◽  
A.A. Kovaleva
Keyword(s):  
Mechanical Properties ◽  
Structural Changes ◽  
Single Phase ◽  
Secondary Phases ◽  
Micro Hardness ◽  
System Alloy ◽  
Quenching Temperature ◽  
Monitor Screen ◽  
X Ray ◽  
Scanning Electron

The purpose of this work is to study the structure and mechanical properties of an aluminum – magnesium system alloy after various types of heat treatment (quenching and ageing). The microstructure of an alloy has been studied by means of Zeiss OBSERVER.D1m microscope combined with a camera and image display on a monitor screen. Micro X-ray spectral analysis was performed by means of Carl Zeiss EVO 50 scanning electron microscope. The micro-hardness of the samples has been measured on prepared metallographic sections by means of DM8 micro-hardness meter. In the course of the process it has been found that quenching the Al-12,78% Mg alloy from temperatures of 430–440 ° C does not lead to the formation of a single-phase solid solution. Ageing at 100 ° C enables the formation of secondary phases. It was noted that with an increase in the quenching temperature, the micro-hardness increases slightly. An increase in the exposure time doesn’t influence greatly the micro-hardness of the alloy, while the structure remains practically unchanged.

Influence of annealing on structural relaxation, crystallization, and deformation behavior of a Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass

2007 ◽  
Vol 22 (7) ◽  
pp. 1849-1858 ◽  
Author(s):  
Kwang Seok Lee ◽  
Jürgen Eckert ◽  
Hyun-Joon Jun ◽  
Young Won Chang
Keyword(s):  
Mechanical Properties ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Deformation Behavior ◽  
Structural Changes ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Compression Tests ◽  
X Ray

The influence of annealing on the structural changes and the mechanical properties of Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vit-1) bulk metallic glass was systematically studied by varying the annealing times at 703 K. The evolution of the structural state at a relatively high temperature within the supercooled liquid region was studied by thermal analysis, x-ray diffraction, high-resolution transmission electron microscopy, extended x-ray absorption fine structure, and dilatometric measurements. The deformation behavior and the mechanical properties were also examined by carrying out hardness and compression tests for the specimens annealed for various times.

scholarly journals Экспериментальное определение механических свойств анодного элемента рентгеновского литографа

2020 ◽  
Vol 90 (11) ◽  
pp. 1838
Author(s):  
Н.А. Дюжев ◽  
Е.Э. Гусев ◽  
А.А. Дедкова ◽  
Д.А. Товарнов ◽  
М.А. Махиборода
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Membrane Structure ◽  
Critical Pressure ◽  
Group Technology ◽  
Analytical Calculation ◽  
Mechanical Stresses ◽  
New Model ◽  
X Ray ◽  
Made In

An anode element of an X-ray lithograph is made in the form of a PolySi/Si3N4/SiO2 membrane structure using group technology. The construction of the stand is modernized to determine mechanical properties of membranes. The critical pressure of membrane structure with a diameter of 250 um varies in the range from 0.484 to 0.56 MPa for 15 samples. The mechanical strength of PolySi/Si3N4/SiO2 structure is 3.13 GPa. The new model in Comsol package shows a good correlation between experimental critical pressure and theoretical mechanical strength of membrane. The distribution of mechanical stresses across membrane by means of modeling and analytical calculation is presented. It is proved that the region of structure discontinuity is localized at membrane/substrate interface.

Influence of fibre pretreatments on characteristics of green fabric materials

2020 ◽  
pp. 096739112094346 ◽  
Author(s):  
R Vinayagamoorthy
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Composite Material ◽  
Composite Materials ◽  
Chemical Treatment ◽  
Natural Fibre ◽  
Sustainable Environment ◽  
Surrounding Matrix ◽  
Fabric Materials ◽  
Made In

The use of natural fibres as composite reinforcements is inevitable in view of developing a sustainable environment. When a natural fibre is extracted from a plant or ground or animal, they are prone to contain impurities and other unwanted substances. By removing these unwanted substances and by enhancing the strengths of the fibres, the reinforcements become predominant to carry the loads in a composite material and thus help the composite to acquire major mechanical properties. Hence, pretreatment methods are adopted for green fibres and it includes a series of chemical treatment, drying, heating in a furnace, and so on. These treatments help to enhance the surface roughness of the fibre, and thus, it increases the bonding strength with the surrounding matrix. The present study gives a clear picture of various pretreatment methods made in different research and their effect on the properties of the composite materials.

scholarly journals Magnetic Field Reconnection in the Hα Eruptive Prominence on September 18, 1995

1998 ◽  
Vol 167 ◽  
pp. 310-313
Author(s):  
Marian Karlický ◽  
Pavel Kotrč ◽  
Stanislava Šimberová ◽  
Miloslav Knížek ◽  
Michal Varady
Keyword(s):  
Magnetic Field ◽  
Detailed Analysis ◽  
Field Line ◽  
Magnetic Field Line ◽  
Radio Burst ◽  
Structural Changes ◽  
Thermal Processes ◽  
Eruptive Prominence ◽  
X Ray

AbstractA violent evolution of the September 18, 1995 eruptive prominence is studied. The fast changes of the prominence structure started immediately after a weak radio burst on 3 GHz indicating the presence of non-thermal processes. A comparison with Yohkoh soft X-ray pictures was made. A detailed analysis of observations indicates magnetic field line reconnection, mainly in the space below the rising Hα prominence. The reconnection processes are manifested by structural changes of the Hα prominence and X-ray loops and also by the character of Doppler velocities in the Hα spectrum formed close to the reconnection space.

The π/2 Side-Reflection Laue Technique and the New Chart

1997 ◽  
Vol 30 (4) ◽  
pp. 456-460 ◽  
Author(s):  
Y.-H. Park ◽  
H.-Y. Yeom ◽  
H.-G. Yoon ◽  
K.-W. Kim
Keyword(s):  
Magnetic Field ◽  
Crystal Orientation ◽  
Structural Changes ◽  
Multiple Reflection ◽  
X Ray ◽  
Dynamic Studies

For the capability of dynamic studies of structural changes of crystals under the environment of heat, electric or magnetic field, the π/2 side-reflection Laue technique is performed in which the X-ray source, the specimen and the film are aligned along an L-shaped track. A new chart has also been designed for the analysis of π/2 side-reflection Laue patterns. This new chart is applied to the analysis of crystal orientation in the π/2 side-reflection Laue technique and to indexing the planes of simultaneous multiple-reflection images in Berg–Barrett topography. Also, the equation of zonal trace has been derived for depicting the zonal curves of configurations of π/2 side-reflection spots and confirming the results which are analyzed by the new chart.

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