scholarly journals Structural Changes of Nitrogen Ferrite After Aging in Temperature Interval up to 100 °С

2021 ◽  
Vol 44 (1) ◽  
pp. 28-33
Author(s):  
Tatyana MECHKAROVA ◽  
Yaroslav ARGIROV ◽  
Daniela SPASOVA ◽  
Aneliya STOYANOVA
Keyword(s):  
Heat Treatment ◽  
Surface Layer ◽  
Aging Process ◽  
Structural Changes ◽  
Electrochemical Corrosion ◽  
Micro Hardness ◽  
X Ray ◽  
Ferrite Structure ◽  
The Individual ◽  
Individual Grains

This paper aims to determine the extent of aging of nitrogen ferrite at temperatures below 100 °C and the structural and strength changes that occur in the process. The tests are carried out on samples of technically pure iron (Armco). The specimens are pre-deformed by tension and re-crystallisation heating to achieve a large-grain ferrite structure. A large-grained structure has been chosen to more accurately track the change in micro-hardness of the individual grains during the aging process. Nitric ferrite results from gas carbonitriding and subsequent hardening. Upon hardening, the samples are stored in a refrigerator, and then the surface layer formed is removed through electrochemical corrosion. Afterwards, aging heat treatment at temperatures below 100 °C is undertaken. After the aging process, micro-hardness of the individual grains is examined and X-ray structural analysis is performed.

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.

Application of Gandolfi X-Ray Diffraction to the Characterization of Reaction Products from the Alteration of Simulated Nuclear Wastes

1980 ◽  
Vol 24 ◽  
pp. 265-269 ◽  
Author(s):  
C. A. F. Anderson ◽  
M. E. Zolensky ◽  
D. K. Smith ◽  
W. P. Freeborn ◽  
B. E. Scheetz
Keyword(s):  
Powder Diffraction ◽  
Individual Particle ◽  
Nuclear Wastes ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Individual ◽  
Individual Grains ◽  
Phase Characterization

AbstractAccurate phase characterization of the alteration products of rad-waste requires the separation and identification of scattered individual grains from among the bulk product. These grains are typically 5 to 100 μm in size. Bulk x-ray powder diffraction will normally not detect these minor phases, and even if the phase can be detected, it often may not be identifiable. The use of the Gandolfi technique with the individual particle not only facilitates the identification, but also allows the assignment of the identification to the specific grain.

scholarly journals Development of an Automatic Ice Fabric Analyser

1985 ◽  
Vol 6 ◽  
pp. 281-283 ◽  
Author(s):  
Y. Mori ◽  
T. Hondoh ◽  
A. Higashi
Keyword(s):  
X Ray ◽  
Crystal Orientations ◽  
Computer Aided ◽  
Polycrystalline Ice ◽  
Thin Polycrystalline ◽  
The Individual ◽  
Individual Grains ◽  
Laue Method

An automatic ice fabric analyser has been developed which precisely determines both c- and a-axes of the individual grains in a thin polycrystalline ice specimen by the use of X-ray Laue method (eg Cullity 1956). The method of analysis is computer-aided indexing of the zone-axes in X-ray Laue patterns. Crystal orientations can be automatically determined by the analyser with an error of approximately 0.6_. Time for analysing one specimen containing 100 grains is approximately three hours at present.

Surface Protection of the Steel Sheet with Zn-Fe Alloys

2010 ◽  
Vol 636-637 ◽  
pp. 985-990 ◽  
Author(s):  
Tamara Radu ◽  
A. Ciocan ◽  
L. Balint ◽  
O. Mitoseriu
Keyword(s):  
Heat Treatment ◽  
Structural Changes ◽  
Galvanized Steel ◽  
Phase Ratio ◽  
X Ray Diffraction ◽  
Surface Protection ◽  
X Ray ◽  
Mathematical Correlation ◽  
Diffusion Phenomena ◽  
Two Phases

The Zn-Fe layers are recommended in automotive industry and in the adders for the following qualities: a better weldability than the zinc-coated plates, very good capacities for painting and lacquer wear resistance, good adherence, lower zinc consumption by layer thickness below 100g/m2. Important transformation of phases takes place during heating of galvanized parts due to mass transfer iron in the zinc layer and Zn-Fe alloy is formed. Galvanized steel samples were heated 10-30 sec. at 500-650oC. Heat treated samples were metallographic ally examined and X- ray diffraction tested with a view to establish structural and chemical composition change due to heat treatment. As a result of microscopic examination (both optical and electronic) and X-ray diffraction testing in coating layer were detected phase ratio changes, according to heat treatment parameters. Considering that the physico-chemical and mechanical properties differ for the two phases and phase ratio is to decide the properties of the product; these structural changes are of great importance in practice. The desirable coating would be a Zn-Fe coating with 8-10% Fe (according to some authors, up to 12% Fe), with a structure consisting mainly of  phase and a small quantity of  phase. The mathematical correlation between diffusion phenomena occurring in layer, depending on temperature and time of heat treatment, and iron content of coating are presented.

An Application of Multigrain Approaches to the Structural Solution of Grains from Polycrystalline Samples

2019 ◽  
Vol 288 ◽  
pp. 119-123 ◽  
Author(s):  
Jav Davaasambuu ◽  
Jon Wright ◽  
Henning O. Soerensen ◽  
Soeren Schmidt ◽  
Henning F. Poulsen ◽  
...  
Keyword(s):  
Structural Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Parameters ◽  
Resolution Level ◽  
Diffraction Patterns ◽  
The Individual ◽  
Individual Grains ◽  
Comparison Of The Results ◽  
Good Agreement

The overlap of diffraction spots from different grains was investigated to understand the influence of experimental factors on the x-ray diffraction data quality and to optimize the experimental parameters for data collection on polycrystalline samples. Diffraction patterns for photoactive polycrystals were indexed and sorted with respect to grains using multigrain approaches. The indexing of diffraction spots and the identification of grains for tetrathiafulvalene-p-chloranil samples were performed using the ImageD11, GrainSpotter, GRAINDEX and Cell_now programs. In many cases, comparison of the results from these programs shows good agreement. For the individual grains from polycrystalline samples, the crystal structure was solved and refined using the SHELXTL program. After the structural refinement of the grains, the best and the average R1 values were 1.93% and 2.06%, respectively, which are on a comparable resolution level with that obtained from the x-ray single crystal measurements.

ATOMIC ENVIRONMENT IN LEAD-BISMUTHATE GLASSES CONTAINING MANGANESE

2003 ◽  
Vol 17 (07) ◽  
pp. 291-301 ◽  
Author(s):  
V. SIMON ◽  
H. BAKO-SZILAGYI ◽  
M. NEUMANN ◽  
S. G. CHIUZBĂIAN ◽  
S. SIMON
Keyword(s):  
Heat Treatment ◽  
Electronic Structure ◽  
Field Strength ◽  
Structural Changes ◽  
Full Width ◽  
Half Maximum ◽  
X Ray ◽  
Gaussian Functions ◽  
Intermediate Range ◽  
Simulation Based

The atomic environment of 20MnO · 80(x Bi 2 O 3 · y PbO ) glass samples having the ratio of bismuth to lead atoms of 8:1 and 3:1 was investigated with respect to the thermal induced structural changes, cationic field strength and electronic structure of the compound. The position and full width at half maximum of X-ray photoelectron peaks were estimated using spectra simulation based on the summation of Lorentzian and Gaussian functions. Data obtained from XPS core-level spectra Bi 4f, Pb 4f, Mn 2p, and O 1s indicate a reduction of glass disorder both by heat treatment and by increasing the PbO content in the samples. The cations behave essentially as network formers that could be correlated with an intermediate range structure.

scholarly journals Grain Orientation and Strain Measurements in Sub-Micron wide Passivated Individual Aluminum Test Structures

2000 ◽  
Vol 612 ◽  
Author(s):  
N. Tamura ◽  
B. C. Valek ◽  
R. Spolenak ◽  
A. A. MacDowell ◽  
R. S. Celestre ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Orientation ◽  
Strain State ◽  
Structural Changes ◽  
Materials Science ◽  
Local Level ◽  
Subsequent Treatment ◽  
Shear Stresses ◽  
X Ray ◽  
Individual Grains

AbstractAn X-ray microdiffraction dedicated beamline, combining white and monochromatic beam capabilities, has been built at the Advanced Light Source. The purpose of this beamline is to address the myriad problems in Materials Science and Physics that require submicron x-ray beams for structural characterization. Many such problems are found in the general area of thin films and nano-materials. For instance, the ability to characterize the orientation and strain state in individual grains of thin films allows us to measure structural changes at a very local level. These microstructural changes are influenced heavily by such parameters as deposition conditions and subsequent treatment. The accurate measurement of strain gradients at the micron and sub-micron level finds many applications ranging from the strain state under nano-indenters to gradients at crack tips. Undoubtedly many other applications will unfold in the future as we gain experience with the capabilities and limitations of this instrument. We have applied this technique to measure grain orientation and residual stress in single grains of pure Al interconnect lines and preliminary results on post-electromigration test experiments are presented. It is shown that measurements with this instrument can be used to resolve the complete stress tensor (6 components) in a submicron volume inside a single grain of Al under a passivation layer with an overall precision of about 20 MPa. The microstructure of passivated lines appears to be complex, with grains divided into identifiable subgrains and noticeable local variations of both tensile/compressive and shear stresses within single grains.

Examination of the Structure and Micro-Hardness of a Laser-Constituted Surface Layer Deposited on the Constructional Steel

2008 ◽  
Vol 23 (1) ◽  
pp. 51-63
Author(s):  
Sylwester Kłysz ◽  
Anna Bień
Keyword(s):  
Surface Layer ◽  
Constructional Steel ◽  
Laser Hardening ◽  
Crystalline Lattice ◽  
Micro Hardness ◽  
Surface Layers ◽  
X Ray ◽  
Macroscopic Examination

Examination of the Structure and Micro-Hardness of a Laser-Constituted Surface Layer Deposited on the Constructional SteelThe paper has been intended to present results of the micro- and macroscopic examination of the structure, as well as measurements of micro-hardness of surface layers of specimens made from the toughening (heat-treatable) constructional steel 50H subjected to laser hardening. Basing on X-ray examination with the DRON-4 and the Seifert XRD 3003 diffractometers, parameters of crystalline lattice and quantitative contents of particular phases have been found.

The Influence of Heating/Cooling Rate on Transformation Temperatures of Co-Base Alloy

2014 ◽  
Vol 782 ◽  
pp. 453-456
Author(s):  
Jana Dobrovská ◽  
Bedřich Smetana ◽  
Hana Francová ◽  
Zdenĕk Jonšta
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Base Alloy ◽  
Transformation Temperatures ◽  
X Ray ◽  
Heating And Cooling ◽  
The Individual ◽  
Dispersive Analyser ◽  
Scanning Electron

Thepaper deals with an experimental measurement of the transformation temperatures of Co-base alloy. Temperatures were determined by means of DTA-method during controlled heating and cooling. The samples in an as-received state were analysed at heating/cooling rates of 2, 5, 10 and 20 °C/min with the use of the equipment Setaram SETSYS 18TM (DTA-method). The samples after various heat treatments were analysed at heating/cooling rate of 5 °C/min by Setaram SETSYS 18TM (DTA-method). On the basis of evaluation of the results the influence of heating/cooling rate on shift of the transformation temperatures was determined. The influence of heat treatment on shift of the transformation temperatures was also studied. The samples in an as-received state and the samples after heat treatment were alsosubjected to the phase analysis by scanning electron microscopy using the microscope JEOL JSM-6490LV equipped with an energy dispersive analyser EDAX (EDS INCA x-act). The individual phases were identified by semi-quantitative X-ray microanalysis.

scholarly journals X-ray tomographies of a water-sensitive granular material (couscous) exposed to high relative humidity: an experimental study

2021 ◽  
Vol 249 ◽  
pp. 08012
Author(s):  
Ilija Vego ◽  
Alessandro Tengattini ◽  
Edward Andò ◽  
Nicolas Lenoir ◽  
Gioacchino Viggiani
Keyword(s):  
Relative Humidity ◽  
Mechanical Response ◽  
Broad Class ◽  
High Relative Humidity ◽  
Image Correlation ◽  
Contact Network ◽  
Sensitive Material ◽  
X Ray ◽  
The Individual ◽  
Individual Grains

Several granular materials are hydro-sensitive, i.e., contact with water severely affects their morphology and mechanical behaviour. To this broad class belong a series of materials of great relevance for the pharmaceutical and food industry. Former studies have been conducted on the effect that moisture or humidity have on granular flow or on the individual grain mechanical response, but the processes occurring at the microlevel and their influence on the overall granular packing behaviour is yet to be fully understood. This study presents an experimental investigation of the response of a water-sensitive material (couscous) exposed to high relative humidity (97%). 4D (3D plus time) x-ray tomographies were acquired in operando. A data treatment approach based on Dicrete Digital Image Correlation (dDIC) is developed and detailed here. This allows for following each individual grain throughout the 4+ days of the humidification test. This, in turn, allows the study of the interand intra-granular strain, which is particularly pronounced in water sensitive materials. The expansion of the individual grains also severely affects the contact network, whose evolving properties are here analysed and correlated to the macroscopic (sample-scale) deformation.

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