Electrometric methods of investigating cryogenic phase transformations of liquid moisture in building materials

1982 ◽  
Vol 42 (3) ◽  
pp. 317-321
Author(s):  
Yu. D. Yasin
Keyword(s):  
Phase Transformations ◽  
Building Materials

scholarly journals PLASMOCHEMICAL MODIFICATION OF WALL BUILDING MATERIALS

2020 ◽  
pp. 11-18
Author(s):  
Vasiliy Bessmertnyy ◽  
O. Puchka ◽  
Diana Bondarenko ◽  
I. Antropova ◽  
Lyudmila Bragina
Keyword(s):  
Aluminum Oxide ◽  
Phase Transformations ◽  
Liquid Glass ◽  
Building Materials ◽  
Sodium Oxide ◽  
Liquid Sodium ◽  
High Alumina ◽  
Oxide Content ◽  
Layer By Layer ◽  
Decorative Coating

the aim of the work is to study the effect of a high-temperature plasma torch on the processes of phase transformations and layer-by-layer modification of the protective and decorative coating on concrete using as a filler a mixture of quartz sand and hollow glass microspheres. The main tasks included: investigation of the processes of evaporation and thermal diffusion of oxides of plasma-coated coatings; study of phase transformations in the melt and its subsequent crystallization in the process of rapid spontaneous cooling of the fused protective and decorative coating; study of the effect of sodium liquid glass on the processes of polymorphic transformations of alumina and the formation of micro-wicks due to the intense diffusion of sodium oxide; study of operational characteristics of protective and decorative coatings. It was established that the initial phases in the protective-decorative coating are α-Al2O3 and CaO∙6Al2O3 (β-Al2O3), and the liquid sodium glass in the coating leads additionally to the formation of Na2O∙11Al2O3. The top layer of the protective and decorative coating is Na–Ca–Al–Si glass with regions of heterogeneities containing an increased content of sodium oxide. The content of aluminum oxide in the protective and decorative coating based on the battle of high-alumina refractory was 95.1 %. The introduction into the coating composition of sodium liquid glass minimizes the processes of dehydration of the binding component and changes the chemical composition of the protective and decorative coating. Reduction of the aluminum oxide content to 83.0 % affects the microhardness indicators. Microhardness of the concrete surface due to the introduction of liquid glass is reduced from 2510 HV to 887 HV.

Effects of Drying Conditions, Phase Transformations, and Carbonation Reactions on Measurements of Sorption Isotherms of Building Materials

2007 ◽  
Vol 4 (8) ◽  
pp. 100459 ◽  
Author(s):  
Kenneth E. Wilkes ◽  
Jerry A. Atchley ◽  
Phillip W. Childs ◽  
Andre Desjarlais ◽  
P. Mukhopadhyaya ◽  
...  
Keyword(s):  
Phase Transformations ◽  
Building Materials ◽  
Sorption Isotherms ◽  
Drying Conditions

The use of high-resolution FESEM to study solid-state phase transformations and reactions

1994 ◽  
Vol 52 ◽  
pp. 1028-1029
Author(s):  
P. G. Kotula ◽  
D. D. Erickson ◽  
C. B. Carter
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Phase Transformations ◽  
High Efficiency ◽  
Sol Gel ◽  
Quantitative Information ◽  
Solid State Reactions ◽  
Critical Dimensions ◽  
Backscattered Electrons ◽  
Backscattered Electron

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

Scanning electron microscopy of asbestos-containing material where the asbestos fibers are considered locked in a binder

1993 ◽  
Vol 51 ◽  
pp. 472-473
Author(s):  
J. R. Millette ◽  
R. S. Brown
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Protection Agency ◽  
Building Materials ◽  
The United States ◽  
Protection Agency ◽  
Asbestos Fibers ◽  
Different Types ◽  
Binder Material ◽  
Scanning Electron

The United States Environmental Protection Agency (EPA) has labeled as “friable” those building materials that are likely to readily release fibers. Friable materials when dry, can easily be crumbled, pulverized, or reduced to powder using hand pressure. Other asbestos containing building materials (ACBM) where the asbestos fibers are in a matrix of cement or bituminous or resinous binders are considered non-friable. However, when subjected to sanding, grinding, cutting or other forms of abrasion, these non-friable materials are to be treated as friable asbestos material. There has been a hypothesis that all raw asbestos fibers are encapsulated in solvents and binders and are not released as individual fibers if the material is cut or abraded. Examination of a number of different types of non-friable materials under the SEM show that after cutting or abrasion, tuffs or bundles of fibers are evident on the surfaces of the materials. When these tuffs or bundles are examined, they are shown to contain asbestos fibers which are free from binder material. These free fibers may be released into the air upon further cutting or abrasion.

A Transmission Electron Microscopical Investigation of Phase Transformations in TiNi

1980 ◽  
Vol 38 ◽  
pp. 340-341
Author(s):  
P. Moine ◽  
G. M. Michal ◽  
R. Sinclair
Keyword(s):  
Electron Microscopy ◽  
Phase Transformations ◽  
Applied Stress ◽  
Structural Changes ◽  
Microscopical Investigation ◽  
Temperature Range ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Diffraction Effects ◽  
Microscopy Images

Premartensitic effects in near equiatomic TiNi have been pointed out by several authors(1-5). These include anomalous contrast in electron microscopy images (mottling, striations, etc. ),diffraction effects(diffuse streaks, extra reflections, etc.), a resistivity peak above Ms (temperature at which a perceptible amount of martensite is formed without applied stress). However the structural changes occuring in this temperature range are not well understood. The purpose of this study is to clarify these phenomena.

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