scholarly journals Chemical heterogeneity as a factor of improving the strength of steels manufactured by selective laser melting technology

2020 ◽  
Vol 242 ◽  
pp. 191
Author(s):  
Vadim ALEKSEEV ◽  
Boris BARAKHTIN ◽  
Anton ZHUKOV
Keyword(s):  
Cross Sections ◽  
Chemical Elements ◽  
Analysis Data ◽  
Raw Material ◽  
Laser Fusion ◽  
Low Carbon ◽  
Electron Microscopic ◽  
Thin Sections ◽  
X Ray ◽  
Powder Particles

The aim of this paper was to establish the causes of the heterogeneity of the chemical composition of the metal obtained by the LC technology. The powdered raw material was made from a monolithic alloy, which was fused by the SLM, the initial raw material was a laboratory melting metal of a low-carbon chromium-manganese-nickel composition based on iron. To determine the distribution pattern of alloying chemical elements in the resulting powder, electron-microscopic images of thin sections were combined with X-ray analysis data on the cross-sections of the powder particles. As a result, it was found that transition (Mn, Ni) and heavy (Mo) metals are uniformly distributed over the powder particle cross-sections, and the mass fraction of silicon (Si) is uneven: in the center of the particles, it is several times larger in some cases. The revealed feature in the distribution of silicon is supposedly due to the formation of various forms of SiO4 upon the cooling of the formed particles. The internal structure of the manufactured powder is represented by the martensitic structure of stack morphology. After laser fusion, etched thin sections revealed traces of segregation heterogeneity in the form of a grid with cells of ~ 200 μm.  

Facile Fabrication of Flower-Like LLM-105 Three-Dimensional Microstructures

2011 ◽  
Vol 239-242 ◽  
pp. 2942-2945 ◽  
Author(s):  
Jin Chen ◽  
Li Li Wang ◽  
Guang Cheng Yang ◽  
Zhi Qiang Qiao ◽  
Fu De Nie
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Raw Material ◽  
Differential Scanning Calorimetric ◽  
Recrystallization Process ◽  
X Ray ◽  
Facile Fabrication ◽  
Lower Temperature ◽  
Scanning Electron ◽  
Poor Solvent

Flower-like LLM-105 three-dimensional microstructures, which consisted of LLM-105 microrods with rectangular cross-sections, were prepared via a smiple template- and surfactant-free recrystallization process using [Bmim]CF3SO3as good solvent and water as poor solvent. A tentative mechanism for the growth of the flower-like LLM-105 three-dimensional microstructures was proposed on the basis of the analysis of X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Comparing with LLM-105 raw material, the thermal decomposition took place at lower temperature and the weight loss has increased for the flower-like three-dimensional microstructures in the differential scanning calorimetric/thermogravimetric (DSC/TG) measurements.

Al-rich industrial residues for mineral binders in ESEE region

2020 ◽  
Author(s):  
Katarina Šter ◽  
Sabina Kramar
Keyword(s):  
Power Plants ◽  
Raw Materials ◽  
Gamma Spectroscopy ◽  
Thermal Power ◽  
Raw Material ◽  
Recycling Rate ◽  
Low Carbon ◽  
X Ray ◽  
Industrial Residues ◽  
Essential Components

<p>Al-rich mineral resources are one of the essential components for the production of the novel sustainable mineral binders. Belite-sulfoaluminate (BCSA) cements, which are considered as low-carbon and low-energy, allows the substitution of natural raw materials with secondary ones. In East-Southeast European countries (ESEE) there are huge amounts of various industrial and mine residues that are either landfilled or currently have a low recycling rate. These residues are generated from mining activities (mine waste) and as a by product of different types of industry, such as thermal power plants, steel plants or the aluminium industry (slags, ashes, red mud, etc.). Within the framework of the RIS-ALiCE project, in cooperation with 15 project partners from Slovenia, Austria, France, Hungary, Serbia, Bosnia and Herzegovina and Macedonia, a network of relevant stakeholders has been established in the field of currently unused aluminium-containing mine and industrial residues. Inside the created network mine and industrial residues have been mapped and valorised in order to evaluate their suitability for the use in innovative and sustainable low CO<sub>2</sub>-mineral binder production. Aluminium-containing residues are characterized with respect to their chemical, physical and radiological composition using different analytical methods such as X ray fluorescence spectroscopy, ICP optical emission spectrophotometry, gravimetry, X ray powder diffraction, gamma spectroscopy, etc. The long-term activity of network between wastes holders/producers and mineral end users will be enabled via developed Al-rich residues registry, including a study of the potential technological, economic and environmental impacts of applying the innovative methodology of the sustainable secondary raw materials management in ESEE region. Developed registry with the data valuable for both, waste providers as waste users in ESEE region, can be later-on upscaled also to other regions of Europe. It will provide the data on the available and appropriate Al-rich secondary resources, which will enablethe production of innovative low-CO<sub>2 </sub>cements.</p><p><strong>Keywords:</strong> secondary raw material, alternative binders, Al-rich residues, networking, mapping, valorisation, registry.</p>

scholarly journals Influence of the type of electrolyte on the morphological and crystallographic characteristics of lead powder particles

2013 ◽  
Vol 78 (9) ◽  
pp. 1387-1395 ◽  
Author(s):  
Nebojsa Nikolic ◽  
Vesna Maksimovic ◽  
Goran Brankovic ◽  
Predrag Zivkovic ◽  
Miomir Pavlovic
Keyword(s):  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Lead Powder ◽  
Scanning Electron Microscopic ◽  
Crystallographic Characteristics ◽  
Powder Particles ◽  
Primary Type ◽  
Secondary Type ◽  
Scanning Electron

Lead electrodeposition processes from the basic (nitrate) and complex (acetate) electrolytes were mutually compared by the scanning electron microscopic and the X-ray diffraction analysis of the produced powder particles. The shape of dendritic particles strongly depended on the type of electrolyte. The dendrites composed of stalk and weakly developed primary branches (the primary type) were predominantly formed from the basic electrolyte. The ramified dendrites composed of stalk and of both primary and secondary branches (the secondary type) were mainly formed from the complex electrolyte. In the both type of powder particles Pb crystallites were predominantly oriented in the (111) plane. Formation of powder particles of the different shape with the strong (111) preferred orientation was discussed and explained by the consideration of the general characteristics of the growth of a crystal in the electrocrystallization processes.

Energy-dispersive X-ray analysis on thin sections and unimpregnated soil material.

1975 ◽  
Vol 23 (2) ◽  
pp. 113-125
Author(s):  
E.B.A. Bisdom ◽  
S. Henstra ◽  
A. Jongerius ◽  
F. Thiel
Keyword(s):  
Chemical Elements ◽  
Research Abstract ◽  
Energy Dispersive ◽  
Topographic Image ◽  
Thin Sections ◽  
Soil Material ◽  
Crystalline Materials ◽  
X Ray ◽  
Loose Soil

A combination of scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDXRA) was used in the study of soil materials. The investigation in situ of components in thin sections was used to estimate chemical elements with atomic numbers 11 upwards, from sodium on. EDXRA could detect chemical elements up to magnifications of X 10 000. The composition of amorphous and micro-crystalline materials cannot be estimated in thin sections by light microscopy but by this technique was clearly displayed. Composition of loose soil material can also be investigated. The material that could be studied by SEM-EDXRA did not need high polishing of the thin section, and the plastic used for impregnation of the soil material was not affected by the investigation.Identification of chemical elements in situ, high resolution of the topographic image and relatively short testing times for the elements make this combination of techniques useful for soil research. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Analysis of Materials from a Late 15th-Early 16th Century Polychromed Wood Sculpture

1990 ◽  
Vol 185 ◽  
Author(s):  
L. P. Stodulski ◽  
V. J. Dorge
Keyword(s):  
Cross Sections ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Red Lead ◽  
The Media ◽  
Staining Techniques ◽  
Wood Sculpture ◽  
Madonna And Child ◽  
Silver Metal

AbstractDuring conservation, The Detroit Institute of Arts' late Gothic carved wooden sculpture, Madonna and Child, was found to have extensive, though fragmentary, remains of the original polychromy and at least four subsequent “restoration” overpaints. The materials present in the original and overpaintings were probed by polarizing microscopic and X-ray diffraction analyses of individual paint specimens, and scanning electron microscopic/energydispersive X-ray analyses of cross sections prepared using an ultramicrotome. Several sections were also studied using ultraviolet fluorescence microscopic staining techniques to determine the nature of the media used.The pigments identified include azurite, lead white, calcite, vermilion, red lead, hematite, red lakes and glazes, smalt and Prussian blue. Gold and silver metal leafs were also detected. The deteriorated remains of the late Gothic pressed brocade technique, and the use of “bronze” paint to approximate genuine gold leaf on a later addition to the sculpture, are also discussed.

scholarly journals THE POSSIBILITIES OF USING LOESS CLAY OF KATTABOG DEPOSIT IN THE PRODUCTION OF CERAMIC PRODUCTS

2020 ◽  
pp. 27-30
Keyword(s):  
Mineralogical Composition ◽  
Physicochemical Analysis ◽  
Raw Material ◽  
Electron Microscopic ◽  
X Ray ◽  
Research Results ◽  
Methods Of Analysis ◽  
Modern Methods ◽  
Technical Properties

The aim of the research was to determine the properties of loess clay in Kattabog deposit (Uzbekistan) to identify possible areas of use. Modern methods of physicochemical analysis are used: spectroscopic, x-ray phase, electron microscopic methods of analysis. The research results showed that the main phases of clay are hydromica, quartz, kaolinite, calcite and orthoclase. Based on the research, it can be stated that the clay of Kattabog deposit has good physical and technical properties and mineralogical composition, which is a valuable raw material for the production of various ceramics, bricks, tiles, majolica and other products.

Correlative light and electron microscopic cytochemical demonstration of biodegradation of polyester implants

1989 ◽  
Vol 47 ◽  
pp. 878-879 ◽  
Author(s):  
J. S. Hanker ◽  
P. Yates ◽  
E. Anderson ◽  
B. Giammara
Keyword(s):  
Cross Sections ◽  
Toluidine Blue ◽  
Glycolic Acid ◽  
Light And Electron Microscopy ◽  
The Body ◽  
Poly Lactic Acid ◽  
Distal Stump ◽  
Electron Microscopic ◽  
Polyglactin 910 ◽  
Thin Sections

There are situations in which an implant material is required only temporarily, e.g., when it is needed as a scaffold to support a nondegradable material until the latter can be incorporated by the body; or when it is required for the uniform release of a therapeutic agent over a long period of time. Biodegradable organic polyesters such as poly(glycolic acid), poly(lactic acid) or their copolymers are of particular interest for such purposes because they undergo hydrolysis (Fig. 1) to form glycolic or lactic acids which are metabolites normal to the body. Recent studies were performed on the use of polyglactin 910 mesh (VicrylR, a lactic-glycolic acid polymer) as a conduit (sleeve) to guide the reconnection of regenerating fibers of the proximal stump of rat sciatic nerve, across an llmm gap, with fibers in the distal stump of the interrupted nerve. For experimental set-up and procedure see reference 3.Gross examination of the repaired sciatic nerves at 1 month showed complete reconnection of the stumps but the VicrylR mesh was not apparent.When cryostat or paraffin sections were made of repaired nerve there was some disruption of structure due to movement of the polyester filaments through the tissue during the sectioning process. This could be avoided by embedding the specimens in epoxy resin and making semi-thin sections with a glass knife. Staining of the sections with either toluidine blue or the PATS reaction (a light and electron microscopy variation of the Keriodic acidSchiff PAS, reaction depositing silver, 5) revealed numerous VicrylR filaments in different degradation stages (Figs. 2-4). The toluidine blue stained filaments were reminiscent of earlier results on methylene blue-stained muscle sections that contained cross-sections of polyglactin 910 braided sutures.

Development of a cantilever-type ferro-actuator using a porous PVDF membrane

2016 ◽  
Vol 230 (20) ◽  
pp. 3594-3605 ◽  
Author(s):  
Kisu Kim ◽  
Seong Young Ko ◽  
Jong-Oh Park ◽  
Sukho Park
Keyword(s):  
Cross Sections ◽  
Polyvinylidene Fluoride ◽  
Fold Increase ◽  
Dip Coating ◽  
Electron Microscopic ◽  
Pvdf Membrane ◽  
X Ray ◽  
Coating Method ◽  
Particulate Leaching ◽  
Pure Pvdf

In this study, we propose a cantilever-type ferro-actuator using porous polyvinylidene fluoride (PVDF) membrane. Generally, a ferro-actuator is fabricated by the absorption of ferro-fluid on a backbone membrane containing strongly magnetized nanoscale Fe particles that are responsive to an external magnetic field. We suggest a porous PVDF membrane fabricated using a zinc oxide (ZnO) particulate leaching method as a backbone membrane of the ferro-actuator to increase the absorption of ferro-fluid. Ferro-fluid is absorbed on the porous PVDF membrane using a dip-coating method. First, we observe from scanning electron microscopic images the surfaces and cross sections of a pure PVDF membrane and the porous PVDF membrane using a ZnO particulate leaching method. Second, an energy-dispersive X-ray spectroscope is used to confirm the configuration of the elements and the absorption of Fe particles in the ferro-actuator. Third, we execute thermogravimetric analysis and X-ray diffraction analysis of the pure PVDF membrane, the PVDF membrane before/after particulate leaching, and of the ferro-actuator using the porous PVDF membrane. Through these analyses, we can confirm that ZnO particles in the PVDF membrane were clearly removed by the particulate leaching method and Fe particles were included in the fabricated ferro-actuator. Finally, we fabricate cantilever-type ferro-actuators using pure PVDF membrane and the porous PVDF membrane and execute blocking force and displacement tests. Compared with the ferro-actuator using the pure PVDF membrane, the ferro-actuator using the porous PVDF membrane had an increased displacements—about a 3-fold increase at the DC input and at the AC input, along with increased blocking force (about a 6-fold increase) at the DC input. Consequently, the concept that a ferro-actuator using the porous PVDF membrane exhibits enhanced actuating performance is validated.

3-D reconstruction of molecular shape from microcrystal thin sections

1983 ◽  
Vol 41 ◽  
pp. 748-749
Author(s):  
S. Cusack ◽  
J.-C. Jésior
Keyword(s):  
Three Dimensional ◽  
Molecular Shape ◽  
Biological Molecules ◽  
Fourier Space ◽  
Single Particles ◽  
Thin Sections ◽  
Standard Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimensional Reconstruction

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).

Chemical modification of the bacterial wall to determine sites of metal deposition

1978 ◽  
Vol 36 (2) ◽  
pp. 350-351
Author(s):  
T. J. Beveridge
Keyword(s):  
Electron Scattering ◽  
Metal Salt ◽  
Metal Deposition ◽  
Suitable Model ◽  
X Ray Diffraction ◽  
Subtilis Cell ◽  
Thin Sections ◽  
X Ray ◽  
Section Data ◽  
Metal Impregnation

The Bacillus subtilis cell wall provides a protective sacculus about the vital constituents of the bacterium and consists of a collection of anionic hetero- and homopolymers which are mainly polysaccharidic. We recently demonstrated that unfixed walls were able to trap and retain substantial amounts of metal when suspended in aqueous metal salt solutions. These walls were briefly mixed with low concentration metal solutions (5mM for 10 min at 22°C), were well washed with deionized distilled water, and the quantity of metal uptake (atomic absorption and X-ray fluorescence), the type of staining response (electron scattering profile of thin-sections), and the crystallinity of the deposition product (X-ray diffraction of embedded specimens) determined.Since most biological material possesses little electron scattering ability electron microscopists have been forced to depend on heavy metal impregnation of the specimen before obtaining thin-section data. Our experience with these walls suggested that they may provide a suitable model system with which to study the sites of reaction for this metal deposition.

Sign in / Sign up

Export Citation Format

Share Document