scholarly journals NEW ALUMINUM ANTIFRICTION ALLOYS INSTEAD OF BRONZES FOR MONOMETALLIC BEARINGS OPERATING UNDER CONDITIONS OF BOUNDARY FRICTION

2016 ◽  
Vol 2016 (4) ◽  
pp. 22-31
Author(s):  
Иосиф Гершман ◽  
Iosif Gershman ◽  
Александр Миронов ◽  
Aleksandr Mironov ◽  
Евгений Гершман ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Strength Properties ◽  
Experimental Investigations ◽  
Sliding Bearings ◽  
Tribotechnical Properties ◽  
The Subject ◽  
Technical Properties ◽  
Materials Used ◽  
Key Words Aluminum ◽  
Antifriction Alloys

In the paper there is presented an investigation on the subject of the substitution of materials used for manufacturing monometallic one-piece sliding bearings. The most widely used material for their manufac-turing is bronze of BrO4Ts4$17 grade which has rather high values of antifriction and strength properties. A whole complex of materials based on aluminum alloys is under consideration. There were investigated eight experimental alloys different with chemistry. In the paper there is described a procedure for carrying out experimental investigations. The comparative tables of the influence of these or those elements upon tribological properties are shown. An evident advantage of aluminum alloys over a compared material – bronze of BrO4Ts4S17 grade is identified. The following tribo-technical properties of experimental alloys such as score-resistance, conformability, durability, frictional moment are considered. Key words: aluminum antifriction alloys, bronze, stress-strain properties, strength, hardness, tribotechnical properties, conformability, scoreresistance, durability, secondary structures.

scholarly journals Влияние ультрамелкозернистой структуры материала на прочностные характеристики сплава алюминия при ударных нагрузках

2019 ◽  
Vol 61 (6) ◽  
pp. 1138
Author(s):  
А.Д. Евстифеев ◽  
И.В. Смирнов ◽  
Ю.В. Петров
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloys ◽  
Severe Plastic Deformation ◽  
Aerospace Industry ◽  
Strength Properties ◽  
Severe Plastic Deformation Technique ◽  
Time Performance ◽  
Wide Range ◽  
Vehicle Production ◽  
Materials Used

Contemporary automotive and aerospace industry have high requirements for the reliability due to growth of the vehicle velocities. At the same time, performance of materials used for the vehicle production often operate under non-standard conditions. The paper presents a comprehensive approach to study and prediction of the behavior of materials subjected to dynamic tensile loads. Aluminum alloys Al-Mg и Al-Cu-Mg are studied in order to demonstrate possibility of the strength properties enchantment using severe plastic deformation technique. Behavior of the materials us investigated for a wide range of loading conditions.

scholarly journals Aluminum casting antifriction alloys with increased capacity to adaptability of friction surfaces

2017 ◽  
Vol 76 (6) ◽  
pp. 336-340 ◽  
Author(s):  
A. E. Mironov ◽  
I. S. Gershman ◽  
E. I. Gershman ◽  
S. M. Zakharov ◽  
P. A. Podrabinnik
Keyword(s):  
Aluminum Alloys ◽  
Laboratory Tests ◽  
Lower Cost ◽  
Cast Aluminum ◽  
Tribotechnical Properties ◽  
Cast Aluminum Alloys ◽  
Operational Tests ◽  
Copper Zinc ◽  
Friction Surfaces ◽  
Antifriction Alloys

The possibility of changing bronze in the manufacture of monometallic cast plain bearings with multicomponent aluminum antifriction alloys is considered. Due to alloying of aluminum with tin, lead, copper, zinc, silicon, magnesium and titanium, it was possible to create alloys with increased ability to adapt friction surfaces. According to laboratory tests, the main results of which are given in the article, it is proved that aluminum alloys on a complex of mechanical and tribotechnical properties are close or superior to the investigated bronze BrO4C4S17. Laboratory tests have shown the possibility of manufacturing monometallic plain bearings from experimental cast aluminum alloys, which by mechanical properties are not inferior to the most solid among antifriction bronzes - bronze BrO4C4S17. On a complex of tribotechnical properties, experimental alloys exceed bronze. Due to their high-fusibility, lower density, lower cost and better workability, aluminum alloys have an almost 3-5-fold advantage over economic indicators before tin bronzes. The scope of the proposed alloys will be determined in the course of bench and operational tests. To date, an experimental batch of monometallic bearings of turbochargers TK 33N-02 has been manufactured from the alloy of the AO6S3M4CT series of “Spets Dizel Servis” (Novosibirsk), which successfully passed the bench tests. Bushings 3404.00.112, 3404.00.032 and bearings 3409.00.20, made from an experimental alloy, showed the possibility of replacing the standard bronze BrO8S12 in these turbochargers. It is advisable to carry out operational tests of bearing sleeves from the alloy AO6S3M4CT for turbochargers TK 34, TK 30 and TK 33, as well as bearing inserts for diesel locomotives.

EVALUATION OF TRIBOTECHNICAL PROPERTIES OF THE COATING OBTAINED BY ELECTRIC SPARK HARDENING

2020 ◽  
Vol 4 (141) ◽  
pp. 157-163
Author(s):  
IL’YA ROMANOV ◽  
◽  
ROMAN ZADOROZHNIY
Keyword(s):  
Wear Resistance ◽  
Reference Sample ◽  
Optical Microscope ◽  
Research Purpose ◽  
Tribotechnical Properties ◽  
Uncoated Surface ◽  
Before And After ◽  
Materials Used ◽  
Friction Track

When applying coatings using various methods on the surfaces of moving parts that work in joints, it is important to make sure that the coatings are strong and wear-resistant in order to return them to their original resource. All existing hardening technologies and materials used to perform coatings have their own characteristics, therefore, the quality of the resulting coatings can be judged only after specific tests. (Research purpose) The research purpose is in evaluating the properties of the coating obtained by the method of electric spark hardening, and its ability to resist friction and mechanical wear. (Materials and methods) Authors conducted tests on the basis of the "Nano-Center" center for collective use. A coating was applied on the BIG-4M unit with a VK-8 hard alloy electrode, tribological properties were evaluated on a CSM Instruments TRB-S-DE-0000 tribometer, the width of the friction track was measured after the test using an inverted OLYMPUS gx51 optical microscope, and samples were weighed before and after the test on a VLR-200 analytical balance. Conducted research in accordance with GOST 23.224-86 and RD 50-662-88 guidelines. (Results and discussion) The article presents performed tests on the run-in and wear resistance of the coating. The samples were worked on with a step-by-step increase in the load. During the tests, the friction force was drawed on the diagram. Authors compared the results with the reference sample, an uncoated surface. (Conclusions) The resulting coating has better run-in and wear resistance compared to the standard, and the increase in wear resistance in dry friction conditions is very significant.

Strength Properties and Chemical Composition of Materials Used in Weathering Steel Bridges

2013 ◽  
Vol 739 ◽  
pp. 292-297 ◽  
Author(s):  
Vit Křivý ◽  
Petr Konečný ◽  
Viktor Urban
Keyword(s):  
Chemical Composition ◽  
Statistical Evaluation ◽  
Strength Properties ◽  
Weathering Steel ◽  
The Czech Republic ◽  
Analysis And Evaluation ◽  
Real Material ◽  
Materials Used ◽  
Hot Rolled ◽  
Rolled Plates

The paper deals with a statistical evaluation of the real material properties of weathering steels used for the construction of motorway bridges in the Czech Republic between 2001 and 2007. The statistical analysis and evaluation is carried out for a range of hot rolled plates made of S355J2W weathering steel. The paper contains an evaluation of the strength properties of the steel and its chemical composition. The paper also contains derived real values of partial factors of materials corresponding to the relevant reliability classes RC1 to RC3 pursuant to the European standard EN 1990.

Influence of Tin on the Tribotechnical Properties of Complex Antifriction Aluminum Alloys

2018 ◽  
Vol 39 (5) ◽  
pp. 394-399 ◽  
Author(s):  
A. E. Mironov ◽  
I. S. Gershman ◽  
E. I. Gershman
Keyword(s):  
Aluminum Alloys ◽  
Tribotechnical Properties

Studies Concerning the Corrosion Behaviour of the Cast Stainless Steel Used for Chemical Industry

2013 ◽  
Vol 371 ◽  
pp. 338-342
Author(s):  
Gheorghe Simionescu ◽  
Mirela Gheorghian
Keyword(s):  
Chemical Industry ◽  
Room Temperature ◽  
Corrosion Behaviour ◽  
Research Work ◽  
Experimental Tests ◽  
Hot Environment ◽  
Chemical Agents ◽  
The Subject ◽  
Materials Used ◽  
Cast Stainless Steel

The current work deals with experimental tests concerning the behaviour of different materials used in chemical industry when are exposed to diverse corrosions environments. During the research work four different metals have been tested, namely T15NiCr180, T15MoNiCr180, W4027 and W4059. The presented work is trying to classify the tested materials function to different chemical environment, different concentration of the environment, different temperature of the environment, and different expose time. Some of the substances which were considered as corrosion environment are: HNO3, H3PO4, NaCl, NH4Cl, C2H5OH, Petrol, NH4NO3, KNO3, K2CO3, Na2CO3, KMnO4, KOH and Ca (OH)2. The concentration of the corrosion solutions varies between 1% and 96%. Tests have been done at room temperature and hot environment of 100°C. Time is playing an important role on evolution of the corrosion. For this reason the samples have been analyzed after 48, 336, 720 and 2160 hours of exposes to chemical agents. To understand the comportment of the subject metals when are used in industry, samples have been tested for longer period of time, respectively 1, 3, 6 and 12 months. After each selected period of time the metallic samples were analyzed and measured to quantify the effect of the environment on the corrosion speed.

Weldability: Effect of Alloying Element Sc, Mn, and Zr on Alloys of the Al-Mg-Sc-Mn-Zr System

2019 ◽  
Author(s):  
V. I. Lukin
Keyword(s):  
Aluminum Alloys ◽  
Practical Importance ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Mg Alloy ◽  
Alloying Element ◽  
Processing Properties ◽  
Alloys Of The Al ◽  
Effect Of Alloying

Scandium in aluminum alloys behaves as the most efficient modifier of the structure of the material and as an agent suppressing recrystallization. This unique behavior of scandium in alloys of the Al-Mg system greatly increases the strength characteristics, whilst retaining on a higher level the ductility and processing properties of deformed semi-finished products. This article describes the effect of complex alloying the Al-6.3% Mg alloy with scandium, manganese and zirconium on the weldability and strength properties of the material is of considerable scientific and practical importance.Investigations.

scholarly journals The straggling of β-particles

1929 ◽  
Vol 125 (798) ◽  
pp. 420-445 ◽  
Keyword(s):  
Classical Theory ◽  
Experimental Investigations ◽  
Theoretical Treatment ◽  
A Value ◽  
Thin Foils ◽  
New Ideas ◽  
The Subject ◽  
The Individual ◽  
Individual Particles ◽  
Α Particles

When a beam of electric particles is passed through a sheet of matter the energy of the individual particles is reduced. The loss of energy is not the same for all the particles so that particles incident on the foil with the same energy emerge with different energies. This dispersion of the energy caused by the foil is known as the "straggling" of the particles. The straggling of α-particles has been the subject of several experimental investigations, and the theory in this case was adequately developed by Bohr in 1915. In the case of β-particles, however, the straggling was not experimentally investigated until quite recently and no theoretical treatment of the phenomenon has been given, the calculations of Bohr being, as he showed, applicable only to α-particles. The purpose of the work described in this paper is to develop a theory of the straggling of β-particles by thin foils and by means of it to interpret the results of experiment. The paper is arranged as follows. In 2 an account is given of the state of the experimental work on the subject, and in particular the effect of the complications introduced by "scattering" are considered. The formula derived by Bohr for the straggling of electric particles is given in 3 and its inapplicability to β-particles demonstrated. The present calculations of the straggling of β-particles are given in 4. The theory of the straggling of electric particles resolves itself into two parts. The first deals with the dynamics of collisions between electric particles and atoms, and is the same whether we are concerned with the straggling or some other phenomena such as ionisation of "stopping power." This may be called the fundamental theory and its requirements may be summarised in the function ϕ (Q) which express the frequency of collisions in which the electric particle loses energy of amount Q. The second part of the theory is the process of calculating the straggling by means of probability theory from the function ϕ . This may be regarded as the straggling theory proper and it is the main subject of 4. When the present calculations were started it was intended to calculate the straggling on the basis of classical theory only, the value of the function ϕ on this theory being definitely known. However, after some practice with the type of calculation involved it was decided to calculate the straggling for other forms of ϕ . From the results obtained it is possible to deduce the straggling corresponding to any form which ϕ may reasonably have, and if a new theory leads to a value of ϕ different from the classical value, the straggling on the new theory may readily be determined. Alternatively this fuller treatment may be used for the reverse process of calculating from the observed straggling the value of ϕ to which it corresponds. This is considered to be the most convenient procedure and in 5 the form of ϕ which explains the experimental results is deduced. this is compared in 6 with the value of ϕ on classical theory. A brief outline is given in 7 of certain new ideas concerning the nature of collisions of electric particles with electrons and atoms.

Your EHD Rig May Not Be As Elastohydrodynamic As You Think

2021 ◽  
Vol 143 (8) ◽  
Author(s):  
Scott Bair ◽  
Wassim Habchi
Keyword(s):  
Film Thickness ◽  
Short Note ◽  
Elastohydrodynamic Lubrication ◽  
Viscosity Coefficient ◽  
Experimental Investigations ◽  
Poor Agreement ◽  
Elastic Regime ◽  
The Poor ◽  
The Subject ◽  
Primary Instrument

Abstract The concentrated contact formed between a steel ball and a glass disc—the optical elastohydrodynamic lubrication (EHD) rig—has been the primary instrument for experimental investigations of elastohydrodynamic film thickness. It has been a source for values of pressure-viscosity coefficient, a difficult-to-define property of liquids. However, comparisons with the pressure dependence of the viscosity obtained in viscometers show little agreement. There are multiple reasons for this failure including shear-thinning and compressibility of the oil. Another reason for the poor agreement is the subject of this short note. The optical EHD rig using glass as one surface will only be in the piezoviscous-elastic (EHD) regime when the pressure-viscosity coefficient is large. For low values, it would be operating in the isoviscous-elastic regime (soft EHD).

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