microstructure

MECHANICAL PROPERTIES AND MICROSTRUCTURE OF CONCRETE INCORPORATING SYNTHETIC ZEOLITE

The effect of natural and synthetic zeolite on the microstructure of cement matrix and mechanical properties of concretes was studied in the article. Results show that the addition of these pozzolanic materials results in the increase both compressive and flexural strength after 28 days of hardening. The concrete incorporating 10 mass.% of synthetic zeolite Na-P1 characterizes the highest compressive and flexural strength that reaches 53.5 and 7.8 MPa and exceeds the strength of reference concrete by 18 and 24%, respectively.

Determination the causes of premature destruction of sheet electrical steel

Sheets of electrical steel are produced by hot and cold working by pressure (mainly by rolling). In this case, the load during rolling should be chosen in such a way as not to impair the electrical properties of the steels. Received two sheets of electrical steel from different production batches. One of the sheets of electrical steel is prematurely destroyed at the stage of machining parts for electrical transformers.

Study on microstructure characterization of fracture frontier of post welds heat treatment and type IV cracking of P92 steel welded joint

In the research work presented in this study microstructure evolution at fracture frontier of crept P92 weld, creep rupture life and effect of creep exposure time on microstructure evolution in fine-grained heat affected zone were performed. Microstructure evolution and creep rupture behavior of metal arc welded joint of P92 steel plate in the as-welded have been studied. The different states of post weld heat treatment (PWHT). (i). post welded heat treatment at 760 C for the 2h (ii).

Effects of the yttria content and sintering temperature on the phase evolution in yttria-stabilized zirconia

The microstructure of YSZ ceramics stabilized by the various amount of yttria, namely 3 mol% Y 2 O 3  (3YSZ), 4 mol% Y 2 O 3  (4YSZ) and 5 mol% Y 2 O 3  (5YSZ) has been studied. Three sintering temperatures, namely 1450 °C, 1500 °C and 1550 °C were used for each series of samples (3YSZ, 4YSZ, 5YSZ). The total area of the monoclinic and cubic zirconia phases in the microstructure of ceramics and the regularities of distribution of these phases were determined by ImageJ.

Influence of heat treatment modes on the performance characteristics of resistive cermet coatings

Dielectric and resistive coatings based on glass ceramics with nickel boride additives have been synthesized. It was found that the microstructure of the resistive coating consists of a large number of phases. X-ray fluorescence analysis revealed the presence of Ni and Cr borides in the structure of the resistive layer. It was found that the change in the structure and specific surface resistance of resistive pastes practically does not affect the temperature coefficient of resistance of the synthesized resistive tracks.

Mechanisms of structural-phase transformations during crystallization of a solder melt

Problem statement. An important requirement is quality assurance of joining materials with minimal overheating of materials, lowering the soldering temperature and suppressing the interaction of the solder with the materials to be soldered. The heating of the solder and the holder should be as uniform as possible and with a minimum temperature difference along the depth. One solution may be to develop more efficient solders and fluxes, adapted to the high heating rates that are typical when using high frequency currents Purpose.

Microstructure and microhardness of nickel-base heat-resistant alloys obtained by directional and equilibrium crystallization

In order to determine the safe operational life of the components of gas turbine engines (GTE), introductory tests of nickel-base heat-resistant alloys (NHRA) have been performed. X-ray fluorescence and X-ray diffraction analyzes, optical microscopy and Vickers hardness measurements provided data on the phase-structural state and mechanical properties of the pristine ZhS6K-VI and ZhS32-VI alloys obtained by equilibrium and high-speed directional crystallization, respectively.

The electronic multilingual dictionary of dental terms: theoretical aspects and practical application

The article deals with major problems, which have arisen in compiling process of electronic multilingual dictionary of dental terms. The article gives a detailed analysis of developing macro-, medio- and microstructure for the abovementioned dictionary and some lexicographical parameters are considered. Some aspects of dictionary entries writing and software for dictionary compiling are highlighted as well.

THE INFLUENCE OF MICROSTRUCTURE 0.45 %C STEEL ON HYDROGEN OVERVOLTAGE AT PRESENCE IRON SULFIDES

The influence of iron sulfides created on 0.45%C steel and microstructure of this steel
on hydrogen overvoltage was investigated. It was shown, that iron sulfides on the surface of
0.45%C steel, usually, decrease hydrogen overvoltage of hydrogen depolarization. The
greatest effect was created by the cansite films. Corrosion of ferrite-perlite microstructure
passes under anode control. Corrosion of troostite microstructure passes under mixed
cathode-anode control, and for sorbite and martensite microstructures it passes under cathode

Optimization of Welding Modes for High-Strength Low-Alloy Domex 700 Steel

The microstructure and hardness of the weld joints of DOMEX 700 steel were investigated. As a result, the optimization of the parameters of robotic arc welding in the environment of protective gases was carried out taking into account the size of the energy per unit length. The optimum modes of welding were determined. The size of the deterioration area, where there is a decrease in hardness in comparison with the main metal, for a thickness of 6 mm is 2.36 mm, and for a thickness of 3 mm is 1.51 mm.