scholarly journals RELIABILITY INCREASE OF THREAD CUTTING WITH TAP BORERS IN SUPER-SMALL HOLES

2020 ◽  
Vol 2020 (11) ◽  
pp. 12-17
Author(s):  
Mikhail Kulikov ◽  
Maksim Yagodkin ◽  
Yuriy Kulikov
Keyword(s):  
Aluminum Alloy ◽  
Considerable Increase ◽  
Reliability Theory ◽  
Thread Cutting ◽  
Tool Failure ◽  
Reliability Indices ◽  
Mechanics Of Materials ◽  
Physical Chemical ◽  
Investigation Methods ◽  
Small Holes

The purpose of this work consists in the reliability increase of thread cutting with the use of tap borers in super-small holes of aluminum alloy parts. The investigation methods used are based on classic regulations of the cutting theory, physical-chemical mechanics of materials, reliability theory and methods of statistical analysis. There are revealed the reasons of thread cutting low reliability and tool failure. The effectiveness of edge anode-machining use at thread cutting is researched. On the basis of data obtained there is carried out a calculation of basic indices of thread cutting reliability. A comparative analysis of the processing reliability indices obtained under standard conditions and with the use of the developed circuit of anode-machining is shown, the effectiveness of the latter use is presented. As a result of the investigations carried out there is developed a technology for thread cutting in super-small holes that ensures a considerable increase of reliability and allows excluding hand work during the process.

scholarly journals The Effect of the Action of Impurities Present in Methanol as a Basis for Automobile Fuel and Their Impact on the Environment

2020 ◽  
Vol 70 (12) ◽  
pp. 4260-4265
Keyword(s):  
Air Pollution ◽  
Aluminum Alloy ◽  
Acid Chloride ◽  
Considerable Increase ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Open Circuit ◽  
Sulfur Oxides ◽  
Pitting Potential ◽  
Hydroxyl Ion

Corrosion of the tank made of aluminum alloy AlMg2,7Mn (5454) has been studied by electrochemical methods in methanolic solution containing different concentrations of acid, chloride, sulphate and water as impurities. In all these cases, the alloy exhibited a sponge passivity. Adding a 1mM solution in fuel leads to a considerable increase in corrosion potential, a 1 mM chlorine solution decreases the pitting potential, and a 1 mM solution of sulfate concentrations does not show any change. In the first phase, due to the hydroxyl ion that surrounds the aluminum, the present water leads to a decrease in the pitting potential.At the same time, the combustion of fuel remains the biggest source of air pollution. The air is polluted by impurities (acids, chlorides, sulphates and water) present in fuels, smoke (incomplete combustion) or nitrogen and sulfur oxides, so it is required to keep them within the limits set by the rules in force. Keywords: aluminium alloy, pitting potential, impurities, polarization curves, open circuit potential

scholarly journals Consequences of colectomy: pathogenetic damages and correction outlooks

2003 ◽  
Vol 2 (4) ◽  
pp. 34-41
Author(s):  
S. R. Bashirov
Keyword(s):  
Degenerative Changes ◽  
Ileal Reservoir ◽  
Mucous Coat ◽  
Physical Chemical ◽  
Clinical Investigations ◽  
Investigation Methods

On the base of experimental and clinical investigations there has been found that continent reservoir ileorectostomies after colectomy under the rectal contents effect had been exposed to degenerative and dysplastic mucous changes. These damages prohibit from stool formation and increase the risk of reservoir malignization. A method of continent reservoir ileorectostomy formation with restraining and areflux mechanism has been developed for pathological transformation of ileal structure. Results of morphological and instrumental investigation methods made on 33 dogs and 6 patients after colectomy show that the restraining and areflux mechanism permits to avoid displastic and degenerative changes in ileal reservoir mucous coat and to recover the stool formation due to motor-evacuation function regulation and keeping the constant physical, chemical and bacterial reservoir and rectum properties after colectomy.

INVESTIGATION OF COMBINED METHOD USE FOR COPPER AND ALUMINUM ALLOY PROCESSING

2020 ◽  
Vol 2020 (11) ◽  
pp. 26-35
Author(s):  
Vitaliy Inozemtsev
Keyword(s):  
Surface Layer ◽  
Aluminum Alloy ◽  
Surface Quality ◽  
Statistical Processing ◽  
Combined Method ◽  
Friction Forces ◽  
Investigation Methods ◽  
Definition Of ◽  
Surface Layer Quality ◽  
Complex Methods

The work purpose: the investigation of obtaining by a surface the required properties and possibility degree to control shaping processes. It is well-known that a shaping process is affected by many factors particularly at complex methods of processing. The analysis of machining condition impact upon surface layer quality of parts allows defining optimum parameters of cutting and increasing parts operation characteristics. Investigation methods: theory, experimental researches, statistical processing of results, mathematical modeling, analysis. Research results: there are defined criteria of surface quality at complex methods of shaping, roles of factors included in processing, mathematical models are formed, recommendations are formulated. Novelty: it consists in the definition of regularities in pore covering at metal ceramic finish machining and definition of processing conditions impact upon pore covering, and also in the definition of efficient conditions of aluminum alloy finishing at the combined method of shaping. Conclusions: as the investigations carried out show the combined methods of impact upon a surface at parts shaping allow reducing also cutter wear, minimizing collateral processing factors connected with heat generation, with increased friction forces and surface layer deformation of a billet at its processing. The combination of machining with electro-chemical processing allows not only having an influence considerable upon surface quality increase, but decreasing technological residual stresses and also contributing to the restoration of mechanical and physical properties of metal surfaces after electro-erosion processing at the expense of surface micro-layer elimination with the acquired thermal changes of structures.

ABOUT THE DEMAND FOR RELIABILITY VALUES OF WATER SUPPLY AND SEWERAGE SYSTEMS

2011 ◽  
Vol 1 (1) ◽  
pp. 57-61
Author(s):  
E. M GAL'PERIN
Keyword(s):  
Water Supply ◽  
Reliability Theory ◽  
Correct Selection ◽  
Xxth Century ◽  
Reliability Indices ◽  
Complex Technical Systems ◽  
Technical Systems ◽  
Selection Of

It has been studied that major drawbacks in formulating the requirements for the reliability of water supply and sewerage systems in existing regulations are related to the fact of their being formulated in the first part of the XXth century. These regulations dont take into account the latest achievements in the reliability theory appeared and developed successfully in the second part of the XXth century. Among these achievements there is a methodologically correct selection of indices for estimating the reliability of complex technical systems. The selection of science-based reliability indices for water supply and sewerage systems and their introduction in the existing regulations is the task of primary importance.

scholarly journals Resolving the test–retest agreement or reliability dilemma

2017 ◽  
Vol 10 (2) ◽  
pp. 205979911770312 ◽  
Author(s):  
Hoben Thomas
Keyword(s):  
Longitudinal Data ◽  
Test Scores ◽  
Reliability Theory ◽  
Reliability Model ◽  
Reliability Indices ◽  
True Scores

Agreement refers to the degree to which an individual i’s test scores match in test–retest settings. Agreement has been thought to be unapproachable with correlational reliability indices. Stable unstable reliability theory extends Spearman’s reliability model and specifies the probability that i’s test–retest true scores match. Thus, agreement and reliability are simultaneously addressed. Two examples, one using longitudinal data, illustrate the procedure.

scholarly journals ABRASIVE DISC IMPREGNATION

2019 ◽  
Vol 2019 (12) ◽  
pp. 13-20
Author(s):  
Liana Gusakova
Keyword(s):  
Friction And Wear ◽  
Chemical Processes ◽  
Mass Composition ◽  
Colloid Chemistry ◽  
Equilibrium Thermodynamics ◽  
New Methods ◽  
Mechanics Of Materials ◽  
Physical Chemical ◽  
Film Forming ◽  
Disc Grinding

In order to solve the problems of the effectiveness increase in parts machining with grinding there are developed impregnated abrasive discs. The impregnated grinding disc application allows increasing effectiveness, intensifying a process, increasing surface smoothness with minimum defects as compared with non-impregnated disc grinding. The investigations of grinding processes were based on the regulations of the theory of friction and wear, theory of cutting, physical-chemical mechanics of materials, physical and colloid chemistry, non-equilibrium thermodynamics. Physical-chemical processes accompanying grinding with impregnated grinding discs are investigated. It is defined that a cutting ability of a grinding disc and its durability increase, glazing decrease and quality improvement of a part worked take place. New methods for obtaining a composition for impregnation are tested. It is substantiated theoretically and confirmed experimentally grinding effectiveness increase at the introduction into an abrasive mass composition a film-forming matter – chromium diiodide.

scholarly journals Peculiarities of chip piling in tap chip grooves during thread-cutting in ultra-small holes

2019 ◽  
Vol 2019 (4) ◽  
pp. 26-30
Author(s):  
Максим Ягодкин ◽  
Maksim Yagodkin
Keyword(s):  
Cutting Process ◽  
Cutting Condition ◽  
Thread Cutting ◽  
Chip Removal ◽  
Small Holes

There is considered a thread-cutting process in ultra-small holes. It is revealed that cutting condition toughening arises because of the chip removal complexity and impossibility of chip complete filing in consequence of insufficient chip grooves volume.

scholarly journals INVESTIGATION OF SOTS AND AMO IMPACT UPON THREAD-CUTTING RELIABILITY IN ULTRA-SMALL HOLES

2018 ◽  
Vol 2018 (4) ◽  
pp. 18-23
Author(s):  
Михаил Куликов ◽  
Mikhail Kulikov ◽  
Максим Ягодкин ◽  
Maksim Yagodkin ◽  
Виталий Иноземцев ◽  
...  
Keyword(s):  
Thread Cutting ◽  
Small Holes

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

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