Creation of Ceramic Nanocomposite Material on the Basis of ZrO2-Y2O3-Al2O3 with Improved Operational Properties of the Working Surface

2013 ◽  
Vol 379 ◽  
pp. 77-81 ◽  
Author(s):  
T.V. Nekrasova ◽  
A.G. Melnikov ◽  
N.V. Martyushev
Keyword(s):  
Aluminum Oxide ◽  
Zirconium Dioxide ◽  
High Strength ◽  
Strength Properties ◽  
Nanocomposite Material ◽  
Working Surface ◽  
Ceramic Samples ◽  
Ionic Implantation ◽  
Ceramic Nanocomposite

In article questions of receiving high-strength ceramics on the aluminum oxide and zirconium dioxide nanopowders basis are considered. As questions of strength properties increase of a ceramic samples surface are studied by ionic implantation methods.

Properties of ceramics obtained on the basis of powders of a mechanical mixture of zirconium hydroxide and dopant

2019 ◽  
pp. 44-48
Author(s):  
Yu. I. Komolikov ◽  
I. D. Kashcheev ◽  
V. I. Pudov
Keyword(s):  
Thermal Decomposition ◽  
Phase Composition ◽  
Flexural Strength ◽  
Specific Surface ◽  
Zirconium Dioxide ◽  
High Strength ◽  
Zirconium Hydroxide ◽  
Mechanical Mixture ◽  
Ceramic Samples ◽  
Structure Phase

The results of studies of the structure, phase composition and specific surface of powders based on zirconium dioxide obtained by the method of thermal decomposition of a mechanical mixture of hydroxide and a stabilizing additive are presented. The forming and sintering of ceramic samples obtained from calcined powders, some properties of ceramics were studied. It has been shown that finegrained dense high-strength ceramics with a flexural strength of 860 MPa and microhardness up to 12‒13 GPa can be obtained from the synthesized powders. Ill. 2. Ref. 12. Tab. 3.

A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 653-664
Author(s):  
IGNACIO DE SAN PIO ◽  
KLAS G. JOHANSSON ◽  
PAUL KROCHAK
Keyword(s):  
Negative Impact ◽  
High Strength ◽  
Strength Properties ◽  
Cellulose Microfibrils ◽  
Paper Strength ◽  
Flow Loop ◽  
Cationic Starch ◽  
Reflectance Measurement ◽  
Drainage Rate ◽  
Complete Study

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

Causes of gear pump fails and methods for their elimination

2020 ◽  
pp. 98-107
Author(s):  
Vitaliy A. Zuyevskiy ◽  
Daniil O. Klimyuk ◽  
Ivan A. Shemberev
Keyword(s):  
Adhesion Strength ◽  
Production Systems ◽  
Low Cost ◽  
High Strength ◽  
Strength Properties ◽  
Research Purpose ◽  
Working Fluid ◽  
Gear Pump ◽  
Repair Service ◽  
Recovery Method

Gear pumps are an important element of many production systems and their replacement in case of failure can be quite expensive, so it is important to have a modern and well-tuned technology for their recovery. There are many methods for restoring the pump's performance, depending on the reason that led to its failure. (Research purpose) The research purpose is in determining what causes most often lead to loss of pump performance, and developing a recovery method that provides the greatest post-repair service life of the pump and low cost of repair. (Materials and methods) Authors took into account that the applied coatings must have sufficient adhesion strength and resistance to mechanical, thermal and corrosion loads during operation. It was found that most often significant leaks of the working fluid, leading to failure, occur due to an increase in the gap between the inner surface of the housing and the gears due to active wear of the housing wells. Authors determined that the method of electric spark treatment of worn-out housing wells is best suited to perform the task (a large post-repair resource and low costs). (Results and discussion) It was found by laboratory studies of the adhesion strength of electric spark coatings with various electrodes that the best transfer of the material to the substrate is provided by bronze electrodes BrMKts3-1. It was noted that the coatings applied using the BrMKts3-1 electrode have high strength properties. (Conclusions) Research conducted in the center for collective use "Nano-Center" VIM confirmed the possibility of effective recovery of the gear pump by electric spark treatment.

scholarly journals Overview of HSS Steel Grades Development and Study of Reheating Condition Effects on Austenite Grain Size Changes

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1988
Author(s):  
Tibor Kvackaj ◽  
Jana Bidulská ◽  
Róbert Bidulský
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
High Strength Steel ◽  
Single Phase ◽  
Hsla Steel ◽  
High Strength ◽  
Strength Properties ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Steel Grades

This review paper concerns the development of the chemical compositions and controlled processes of rolling and cooling steels to increase their mechanical properties and reduce weight and production costs. The paper analyzes the basic differences among high-strength steel (HSS), advanced high-strength steel (AHSS) and ultra-high-strength steel (UHSS) depending on differences in their final microstructural components, chemical composition, alloying elements and strengthening contributions to determine strength and mechanical properties. HSS is characterized by a final single-phase structure with reduced perlite content, while AHSS has a final structure of two-phase to multiphase. UHSS is characterized by a single-phase or multiphase structure. The yield strength of the steels have the following value intervals: HSS, 180–550 MPa; AHSS, 260–900 MPa; UHSS, 600–960 MPa. In addition to strength properties, the ductility of these steel grades is also an important parameter. AHSS steel has the best ductility, followed by HSS and UHSS. Within the HSS steel group, high-strength low-alloy (HSLA) steel represents a special subgroup characterized by the use of microalloying elements for special strength and plastic properties. An important parameter determining the strength properties of these steels is the grain-size diameter of the final structure, which depends on the processing conditions of the previous austenitic structure. The influence of reheating temperatures (TReh) and the holding time at the reheating temperature (tReh) of C–Mn–Nb–V HSLA steel was investigated in detail. Mathematical equations describing changes in the diameter of austenite grain size (dγ), depending on reheating temperature and holding time, were derived by the authors. The coordinates of the point where normal grain growth turned abnormal was determined. These coordinates for testing steel are the reheating conditions TReh = 1060 °C, tReh = 1800 s at the diameter of austenite grain size dγ = 100 μm.

scholarly journals Soil microbiomes mediate degradation of vinyl ester-based polymer composites

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Adam M. Breister ◽  
Muhammad A. Imam ◽  
Zhichao Zhou ◽  
Md Ariful Ahsan ◽  
Juan C. Noveron ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Polymer Composite ◽  
Structural Integrity ◽  
Abiotic Factors ◽  
High Strength ◽  
Strength Properties ◽  
Naturally Occurring ◽  
Structural Applications ◽  
Acrylate Esters ◽  
Bacterial Groups

AbstractPolymer composites are attractive for structural applications in the built environment due to their lightweight and high strength properties but suffer from degradation due to environmental factors. While abiotic factors like temperature, moisture, and ultraviolet light are well studied, little is known about the impacts of naturally occurring microbial communities on their structural integrity. Here we apply complementary time-series multi-omics of biofilms growing on polymer composites and materials characterization to elucidate the processes driving their degradation. We measured a reduction in mechanical properties due to biologically driven molecular chain breakage of esters and reconstructed 121 microbial genomes to describe microbial diversity and pathways associated with polymer composite degradation. The polymer composite microbiome is dominated by four bacterial groups including the Candidate Phyla Radiation that possess pathways for breakdown of acrylate, esters, and bisphenol, abundant in composites. We provide a foundation for understanding interactions of next-generation structural materials with their natural environment that can predict their durability and drive future designs.

Correlation Between Microstructure and Mechanical Properties of Diffusion Brazed MAR-M 247

1993 ◽  
Author(s):  
W. Miglietti
Keyword(s):  
Filler Metal ◽  
Turbine Blades ◽  
High Strength ◽  
Strength Properties ◽  
Joint Microstructure ◽  
Investment Cast ◽  
Diffusion Brazing ◽  
Brazed Joints ◽  
Joining Process ◽  
Turbine Blading

Diffusion brazing is a joining process utilized in the manufacture and repair of turbine blades and vanes. MAR-M247 is an investment cast Ni-based superalloy used for turbine blading and has good strength properties at high temperatures. The objectives of this work was to develop a diffusion brazing procedure to achieve high strength joints. A commercially available diffusion brazing filler metal of composition Ni-15Cr-3,5B of 100 μm thickness was used. With the desire to eliminate brittle centre-line phases, the effects of the processing variables (only temperature and time) on the joint microstructure was studied. Once the metallurgy of the joint was understood, mechanical property assessments were undertaken i.e. tensile and creep rupture tests, and the latter being the severest test to evaluate joint strength. The results demonstrated that the diffusion brazed joints had nearly equivalent mechanical strength to that of the parent metal. This showed that the resultant diffusion brazing parameters enabled effective and reliable joining of MAR-M247.

EVALUATION OF THE MICROSTRUCTURE OF ZIRCONIUM DIOXIDE DURING ITS PROCESSING WITH VARIOUS TYPES OF DIAMOND TOOLS FOR FIXED PROSTHETICS IN DENTISTRY

2021 ◽  
pp. 57-64
Author(s):  
Богдан Романович Шумилович ◽  
Владимир Владимирович Ростовцев ◽  
Олеся Борисовна Попова ◽  
Светлана Николаевна Крюкова ◽  
Евгений Сергеевич Станиславчук ◽  
...  
Keyword(s):  
Zirconium Dioxide ◽  
Diamond Tool ◽  
Synthetic Diamond ◽  
Mechanical Action ◽  
Structure And Properties ◽  
Single Application ◽  
Diamond Tools ◽  
Ceramic Samples ◽  
Different Types

Цель: определить характер механического воздействия на структуру образцов из керамики на основе диоксида циркония при её обработке различными алмазными инструментами, и оценка пригодности инструмента с различным способом фиксации абразива при многократном применении для дальнейшего использования. Материал и методы. Материал исследования - образцы на основе метастабильного тетрагонального диоксида циркония, изготовленные в зуботехнической лаборатории и стандартизированные по толщине (1 мм). Оценку влияния механических напряжений на структуру и свойства исходного материала проводили методом перфорации образца алмазными борами, содержащими специальный абразив для обработки циркония. Исследовались боры с различным типом фиксации абразива: № 1 - алмазный бор c синтетическим абразивом, закрепленным по типу ERA; №2 - алмазный бор с композитной фиксацией абразива импортного производства; №3 - отечественный алмазный бор с нанесением и фиксацией абразива методом гальванопластики. Методом сканирующей электронной микроскопии получали изображения результатов механического воздействия боров на образцы диоксида циркония при однократном и пятикратном использовании бора. Исследование структуру самого алмазного инструмента на предмет его пригодности для дальнейшего использования. Результаты. При однократном применении все представленные боры сохраняют микроструктуру диоксида циркония, что позволяет в дальнейшем работать с образцами с использованием адгезивной техники. При пятой обработке боры № 3 не пригодными для работы с керамическим образцом, боры № 2 остаются частично пригодными, боры №1 сохраняют свою пригодность для дальнейшего использования. Заключение. Керамические образцы на основе на основе диоксида циркония изменяются в процессе механического воздействия, что зависит от вида применяемого бора и кратности его применения. Боры с синтетическим алмазным абразивом на базе ERA остаются работоспособными даже после их пятикратного применения, боры с композитной фиксацией абразива к пятому применению остаются относительно работоспособными, а боры с гальванопластической фиксацией абразива к пятому применению приходят в полную негодность Purpose: to determine the nature of the mechanical impact on the structure of samples made of ceramides based on zirconium dioxide when it is processed with various diamond tools, and to assess the suitability of tools with different methods of fixing the abrasive with multiple applications for further use. Material and methods. The material of the study is samples based on metastable tetragonal zirconium dioxide manufactured in a dental laboratory and standardized in thickness (1 mm). The influence of mechanical stresses on the structure and properties of the source material was evaluated by perforating the sample with diamond bores containing a special abrasive for processing zirconium. Bores with different types of abrasive fixation were studied: № 1-diamond boron with synthetic abrasive fixed by ERA type; № 2-diamond boron with composite fixing of imported abrasive; № 3 - edematous diamond boron with applying and fixing the abrasive by electroplating. Scanning electron microscopy was used to obtain images of the results of mechanical action of boron on samples of zirconium dioxide with a single and five-fold use of boron. Investigation of the structure of the diamond tool itself for its suitability for further use. Results. With a single application, all the presented burs preserve the microstructure of the samples, which makes it possible to preserve the suitability of the sample for further work using adhesive technology. At the fifth processing, boron № 3 is not suitable for working with a ceramic sample, boron № 2 remains partially suitable, boron № 1 retains its suitability for further use. Conclusion. Ceramic samples based on zirconium dioxide change in the process of mechanical action, which depends on the type of boron used and the multiplicity of its application. Bores with synthetic diamond abrasives based on ERA remain workable even after their five-time application, bores with composite Abrasive fixation remain relatively workable by the fifth application, and bores with electro plastic fixation of the abrasive by the fifth application become completely unusable

Influence of Granulometric Composition and Type of Fillers and Additives on the Strength and Biostability of Cement Composites Based on Dry Building Mixtures

2021 ◽  
Vol 1043 ◽  
pp. 163-175
Author(s):  
Ekaterina Suraeva ◽  
Tatyana Elchishcheva ◽  
Dmitry Svetlov ◽  
Vasiliy Smirnov ◽  
Victor Afonin ◽  
...  
Keyword(s):  
Quartz Sand ◽  
Fungal Growth ◽  
High Strength ◽  
Strength Properties ◽  
System Structure ◽  
Fungal Resistance ◽  
System Stability ◽  
Environment Effects ◽  
Cement Binder ◽  
Insoluble Compounds

The structure of filled cementitious composite materials is formed as a result of hardening with the formation of a crystalline framework. The filler is involved in the building material crystal system structure formation. Chemically active fillers promote intensive release of hydration products that bind into insoluble compounds and increase the system stability. When developing the formulations for dry building mixtures, it is effective to use several fillers with different properties that complement each other, and biocidal additives increasing the materials resistance to environment effects formed by mold fungi. To create modified dry building mixtures based on cement binder, materials such as filler made of quartz sand of various fractions, fillers chrysotile and clinoptilolite and biocidal additives of the Teflex series were used. The composition with sand grains of 0.16–0.315 mm in size showed high strength properties in bending and compression. The introduction of chrysotile in an amount of 3% by weight of cement and quartz sand with a particle size of 0.16–0.315 mm increases the compressive and flexural strength by 7 and 13%, respectively, compared with the control composition. Clinoptilolite, introduced in an amount of 20% of the cement mass instead of one of the quartz sand fractions, increases the compressive strength of the composites up to 5%. The introduction of the Teflex series additives in the amount of at least 1% by weight of the binder ensures the composites’ fungal resistance. The additive “Teflex disinfectant” in an amount of at least 3% of the cement mass gives the composites fungicidal properties, the zone of no fungal growth on the nutrient solution near the infected samples is 4 mm.

Mechanical and Thermal Properties of Magnesia Binder Based on Natural and Technogenic Raw Materials

2021 ◽  
Vol 320 ◽  
pp. 181-185
Author(s):  
Elvija Namsone ◽  
Genadijs Sahmenko ◽  
Irina Shvetsova ◽  
Aleksandrs Korjakins
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Raw Materials ◽  
High Strength ◽  
Strength Properties ◽  
Waste Materials ◽  
Mechanical And Thermal Properties ◽  
Experimental Part ◽  
Technogenic Raw Materials ◽  
Caustic Magnesia

Because of low calcination temperature, magnesia binders are attributed as low-CO2 emission materials that can benefit the environment by reducing the energy consumption of building sector. Portland cement in different areas of construction can be replaced by magnesia binder which do not require autoclave treatment for hardening, it has low thermal conductivity and high strength properties. Magnesium-based materials are characterized by decorativeness and ecological compatibility.The experimental part of this research is based on the preparation of magnesia binders by adding raw materials and calcinated products and caustic magnesia. The aim of this study was to obtain low-CO2 emission and eco-friendly material using local dolomite waste materials, comparing physical, mechanical, thermal properties of magnesium binders.

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