Composition Materials With Metal Matrix Condensed from the Vapor Phase

In this article, the present-day problems of microporous condensed materials obtained from the vapor phase are discussed. The pore sizes are regulated by the amount of the second phase concentration and the deposition temperature. The oxides, fluorides, and sulfides can be used as the second phase and non-removable inclusions. The open porosity can be regulated from 0% to 50 %of the porosity and with average porose sizes of 0.1 to 8 µm. The condensed micro-porous materials can be deposited in coating form or the form of massive bulk sheet materials with a thickness of up to 6 mm and a diameter of 1m.

Composition Materials with Metal Matrix Condensed from the Vapor Phase

The data of condensed from vapor phase disperse reinforced materials design is presented. It is shown that the material's mechanical properties depend on matrix type, types of dispersed particles, temperature and roughness of the substrate, purity of initial materials, and its evaporation speed.

Relationships of urolithogenicity index with some components of urine composition in healthy old female rats

Background. Despite the long history, the results of studies of the impact of balneotherapy in the resort of Truskavets on the lithogenicity of urine are ambiguous, so the topic remains relevant. The aim of this study was to determine the relationship between the lithogenicity index of urine and a number of components of its composition. Materials and Methods. Experiment was performed on 60 healthy old female Wistar rats 220-300 g. Ten animals remained intact, using daily water from drinking ad libitum. Other animals for 6 days were loaded through the tube with daily and various mineral waters at a dose of 1,5 mL/100 g of body mass. The day after the completion of the drinking course collected daily urine, which determined the content of a number of components of the composition. We calculated urine lithogenicity index (Lith) by the formula: Lith = (Uric acid•Calcium/Magnesium•Creatinine)0,25. Results. The most significant effect on the Lith is the concentration of magnesium (r=-0,730), followed by uric acid (r=0,583), calcium (r=0,352) and creatinine (r=-0,298). Medium molecular polypeptides, catalase, sodium, phosphates and urea has been identified as prolithogenic factors while tubular reabsorption of water as litholytic factor. The chemical composition of the fluids consumed by animals has little effect on the lithogenicity index of urine. Conclusion. Both prolithogenic and litholytic factors are present in the urine, which depend little on the chemical composition of the fluid used.

On “4321” Strategy of English Continuation Writing for Senior High School Students

Under the new form of education, the continuation writing task is officially incorporated into college entrance examination English. This is a collision of imitation and innovation, and it is a very good direction of education and teaching. But at the same time, it brings challenges to both English teachers and students who have been stuck in the rigid writing mode. Therefore, they should change writing patterns, select high-quality composition materials reasonably, and set up interesting plots. Then, teachers should organize valid information to improve the students’ self-improvement levels. Finally, they should integrate high-quality articles to stimulate writing interest and enthusiasm, thus promoting students’ continuation wring abilities.

Design and Analysis of Piston Rings by Using Hyper Elastic Materials of Dynamic Engine Assembly

The piston ring is one of the main components of an internal combustion engine. Its main purposes are to seal the combustion chamber of engine. The main objective of this work is to develop the design modeling and then analysis of stress and deformation of the piston rings by using different materials like Grey cast iron, elastomer and Titanium alloy by using ansys software and to investigate these three materials behavior which are used for the piston ring. The project shows the components involved in the single cylinder engine assembly and their operation. Finally we are checking out three materials behaviors which are used for piston rings. This research paper deals with to reduce the friction of a piston ring while maintaining a Large oil film load-carrying capacity, an approach comprising of the inverse method, modeling and analysis of piston rings using Structural and rigid dynamics is deliberated in order to quantify the stress that the rings can bear. Many researchers had considered that the entire surface of the ring was enveloped in an oil film, but much experimental research has discovered that not all the entire surface was soaked. The various parameters studied under structural analysis are displacement and ultimate stress limit using three Different composition materials. A cumulative analysis is performed which considers the combined effect of mechanical and load for determination of the dimensions of the rings.

Forecast of mechanical properties of metal products

Introduction. The mechanical properties of the metal depend primarily on their chemical composition and structure. The structure of metal materials is formed under the influence of different temperature modes of manufacture and cooling. Models for predicting the mechanical properties of steels and cast irons are based on the influence of chemical composition and structure. The paper considers an approach that allows to evaluate the mechanical properties of rolling (C) cast iron rolls with a pearlitic (P) matrix depending on the complex influence of the elements of their chemical composition. Materials and methods. The working area of СПХН roll cast iron samples from the surface up to 50 mm doped with chromium (X) and nickel (H) was investigated. The carbide content varied from 10 to 15 %; and lamellar graphite did not exceed 2 %. The results of the experiment. In the work for modeling the mechanical characteristics of cast iron rolls used the method of planning experiments. The choice of this technique is due to the multi-parameter technology of production of solid metal casting. The application of this technique allowed to obtain models for predicting the mechanical characteristics of roll cast iron SPHN depending on the influence of the elements of the chemical composition of the rolls (C, Si, Mn, P, S, Cr, Ni). The error in predicting the tensile strength sВ, bending strength sзгин bending and hardness according to the Shore HSD method did not exceed 5,89 %. When checking the models for convergence of results by Fisher's criterion at a critical value of Fcrit = 2,400 for sВ, this coefficient was 1,249; for sзгин fold was 1,289 and for HSD - 1,012. To analyze the effect of carbon on mechanical characteristics, two-dimensional dependence plots are constructed. Conclusions. Within the operating values of the parameters of the chemical composition of cast iron rolling mills СПХН-45 in accordance with existing regulations, a forecast of their mechanical characteristics within the allowable limits of error of experimental data. The results of the work allow to obtain mathematical models in the process of production of rolls of the СПХН brand to quickly establish their chemical composition within the standard technology in accordance with the customer's requirements for these mechanical characteristics. In addition, the obtained models can predict these characteristics of the manufactured rolls with minimal material and time costs. Keywords: rolling mills; elements of chemical composition; mechanical characteristics; multiparameter technology

Regularities of the influence of submicron ceramic powders TiO2, AlN, Cr2O3 on the tribological properties of a friction material

Friction units for automotive and special vehicles are designed to operate under boundary friction conditions. Modern vehicles contain friction assemblies that use friction materials. Currently, friction materials are actively used: based on thermosetting resins; pulp and paper-based materials; sintered powder materials; materials of carbon or carbon composition; materials with a ceramic matrix. The development of a unified understanding of the effect of the size and chemical nature of ceramic additives on the processes occurring in a friction material during friction is very important and can be obtained both on the basis of experimental and theoretical studies. The paper presents the results of a study of the effect of submicron TiO2, Cr2O3, AlN powders with a size of 0.2-0.5 microns on the tribotechnical properties of a frictional material based on copper intended for operation under boundary friction conditions. It was found that when using the addition of Cr2O3 powder, the greatest increase in the value of the friction coefficient is noted - from 0.042 to 0.082, a slightly smaller increase in the friction coefficient is shown by the use of AlN and TiO2 defects - 0.042-0.074 and 0.042-0.060, respectively. The least wear of the friction material was obtained when using 3.0 vol. % aluminum nitride additive - 2.1 microns / km. Increasing the addition of any of the submicron powders by more than 7 vol. % leads to a significant decrease in wear resistance. This is due to the formation on the surface of the friction material of a modified layer containing ceramic particles and the metallic phase of the friction material. For the friction material, an unstable value of the friction coefficient and increased wear were recorded

Effect of Aluminum Alu C and HCM-40 and Yttrium Oxides Y2O3 on the Properties of Composition Materials Based on Perfluorinated «Neofton N» Rubber

The properties of two groups of composite materials (CM) based on perfluorinated rubber (FFKM) «Neofton-N» with different contents of trivalent metal oxides: pyrogenic aluminum oxide (Alu C), hollow corundum microspheres (HCM-40) and nanodispersed powder yttrium oxide (Y2O3) were obtained and investigated,. The rheometric characteristics of CM cured with 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (BOAP) and perfluorohexamethylene-bis-perfluorohexylimidoylamidine (DPIA-65) and their mechanical properties were determined. Thermogravimetric analysis was used to study their temperature parameters. The possibility of obtaining CM with a high level of properties, operable in the temperature range 250–330 °C, has been shown.