scholarly journals Method of providing wear-resistance of the blades of paddle mixers.

2019 ◽  
pp. 32-35
Author(s):  
G. V. Petrishin ◽  
V. M. Bystrenkov ◽  
V. I. Odarchenko
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Protective Coatings ◽  
Thermal Spraying ◽  
Technical Solution ◽  
Scientific Publications ◽  
Actual Problem ◽  
Advantages And Disadvantages ◽  
Operational Tests ◽  
Paddle Mixer

The work is devoted to solution of the actual problem to increase the service life of blade mixers used in the foundry industry. The existing methods for ensuring wear resistance of mixing blades are described, their advantages and disadvantages are indicated. Based on the analysis of scientific publications a technical solution for applying protective coatings to the blades of the mixer using gas-thermal spraying has been proposed. The results of laboratory studies of the wear rate of gas-thermal coatings from various powder mixtures of the Ni-Cr-B-Si system under conditions of abrasive wear are presented. The results of operational tests of experimental products under conditions of corrosion and abrasive wear during the operation of a paddle mixer are given. The composition of the powder mixtur ensuring maximum wear resistance of the mixer blades was developed.

scholarly journals STATE OF THE ART USAGE OF RADIOLOGICAL AND ACOUSTIC METHODS FOR THE DIAGNOSIS OF PNEUMONIA, INCLUDING THOSE CAUSED BY SARS-COV-2 VIRUS, IN CHILDREN. Review

2021 ◽  
Vol 17 (2) ◽  
pp. 114-124
Author(s):  
Y.V. Marushko ◽  
O.V. Khomych ◽  
T.V. Hyshchak ◽  
O.L. Tarynska ◽  
G.O. Shchegel
Keyword(s):  
Clinical Symptoms ◽  
External Irradiation ◽  
Ray Method ◽  
Scientific Publications ◽  
Actual Problem ◽  
Advantages And Disadvantages ◽  
Treatment Indications ◽  
Ultrasound Diagnostics ◽  
Wide Range ◽  
Acoustic Methods

Relevance. Pneumonia is an actual problem of practical medicine. Diagnosis of pneumonia is quite complex and requires a comprehensive study, taking into account both clinical symptoms and the results of paraclinical research methods. Objective. The aim of the work is to generalize the data of the literature and our own experience of modern radiological and acoustic methods of pneumonia diagnosis. Methods. Analysis of scientific publications in the international electronic scientometric databases Scopus, PubMed by keywords. Search depth – 15 years (2007-2021). Results. The article summarizes its own data and presents a scientific review of the medical literature, which is devoted to the analysis of the problem of diagnosing pneumonia at different stages of treatment. Indications and contraindications to use, advantages and disadvantages of X-ray method, CT method and ultrasound diagnostics are described. The characteristic of a new method of hardware diagnostics which without external irradiation gives the chance to carry out primary acoustic remote diagnostics of pneumonia is resulted. Conclusion. Today there is a wide range of instrumental methods of studying the respiratory system that allow accurate diagnosis, but have some limitations in use in clinical practice, in particular in pediatrics. Promising is the development of new acoustic methods that have high diagnostic value, lack of additional radiation and contraindications.

scholarly journals The resistance of ledeburitic tool steels against the abrasive wear

2012 ◽  
Vol 60 (6) ◽  
pp. 231-242 ◽  
Author(s):  
Jaromír Liška ◽  
Josef Filípek
Keyword(s):  
Wear Resistance ◽  
Laboratory Test ◽  
Abrasive Wear ◽  
Structural Steel ◽  
Aluminium Alloys ◽  
Structural Steels ◽  
Tool Steels ◽  
Maximum Hardness ◽  
Resistant Material ◽  
Operational Tests

The ledeburitic tool steels which used to be used mainly for cutting and shaping tools nowadays are frequently used for a manufacture of injection moulds, moulds for pressure castings of aluminium alloys and for moulds for ceramics processing. The article deals with findings of ledeburitic tool steels resistance against abrasive wear. For the tests there were prepared the test samples of ledeburitic tool steels 19 436 and 19 573 (both according to ČSN). Moreover there were prepared the samples from structural abrasion resistant material Hardox 450 and from unalloyed structural steel 11 373 (according to ČSN). A wear resistance was examined by means of a laboratory test with an abrasive cloth and the Bond’s device. Hereafter the article deals with a possibility of utilisation of ledeburitic alloyed steels for a manufacture of tools for a land processing. For the examination of a resistance against wear in land there was made a plough test in which the tested samples were mounted on plough blades. By means of both the laboratory and operational tests there was found multiple higher resistance against wear of ledeburitic tool steels rather than of structural steels. During a land processing there was found unsuitability of steels processed for a maximum hardness, which came out as fractures of several samples.

THE INFLUENCE OF HARDNESS OF POLYURETHANE ON ITS ABRASIVE WEAR RESISTANCE

Tribologia ◽  
2016 ◽  
Vol 268 (4) ◽  
pp. 29-39 ◽  
Author(s):  
Dymitr CAPANIDIS
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Tribological Properties ◽  
Protective Coatings ◽  
Road Transport ◽  
Operational Reliability ◽  
Abrasive Wear Resistance ◽  
Transport Equipment ◽  
The Impact

This paper presents the experimental determination of the effect of hardness of the polyurethane (PUR) in a form of the elastomer foam used in various parts of machines or appliances subjected to intensive abrasive wear. Such elements, among others, are static and dynamic technical seals, bumpers, shock-absorbing parts in joints of machine components, and elements of transport equipment in mining or in aggregate and mineral processing [L. 1–3]. Intensive abrasive wear also concerns parts of agricultural and construction machines, road transport, and transport packaging, as well as protective coatings, housing or shields of various machines, and equipment elements [L. 4, 5]. An increase in the abrasive wear resistance of directly determines an increase in the durability and operational reliability of machines and equipment [L. 6]. The hardness of the elastomeric polyurethane influences its physicomechanical and tribological properties [L. 7]. So far, relatively few works have focused on research into the effect of various factors, including the hardness of PUR on the tribological properties of PUR. The aim of this study is to broaden knowledge on the impact of the polyurethane hardness on its resistance to abrasive wear.

EFFECT OF SURFACE TREATMENT ON ABRASIVE WEAR RESISTANCE OF SEEDER COULTER FLAP

2016 ◽  
Vol 23 (03) ◽  
pp. 1650007 ◽  
Author(s):  
MARTA PACZKOWSKA ◽  
JAROSŁAW SELECH ◽  
ADAM PIASECKI
Keyword(s):  
Wear Resistance ◽  
Surface Modification ◽  
Abrasive Wear ◽  
Surface Treatment ◽  
Surface Condition ◽  
Thermal Spraying ◽  
Abrasive Wear Resistance ◽  
Laser Surface ◽  
Flame Spraying ◽  
Laser Surface Modification

The aim of this study was to investigate the effect of the surface condition of the coulters of a Poznaniak mechanical seeder working in a sand medium on their abrasive wear resistance. Two types of coulter flap surface treatments were performed. The first treatment method was flame spraying, performed with the use of Eutalloy 10112 powder and other method was laser surface modification consisting in remelting a piece of the coulter flap tip by means of TRUMPF’s CO2 molecular laser. The study involved the use of a purpose-built laboratory test stand dedicated to testing wear in a sandy medium. The study revealed that surface treatment changes surface microstructure and thus improves its hardness by [Formula: see text] to 3 times, which translates into two- to six-fold improvement in wear resistance per hectare of cultivated field. Laser surface modification is more economical than thermal spraying and that the coulter flap surface area modified by thermal spraying was much greater than in the case of laser remelting, and finally that the average wear measured as a weight loss of tested coulters was comparable, one can conclude that in the analyzed context laser surface modification will probably prove more efficient than flame spraying. The study showed that there exist ready-to-use technologies for improving operational performance and delaying terminal wear.

scholarly journals Obtaining a combined epoxy-acrylic dispersion

2021 ◽  
Vol 83 (1) ◽  
pp. 278-283
Author(s):  
R. G. Domnichenko ◽  
G. Y. Vostrikova ◽  
S. S. Nikulin
Keyword(s):  
Wear Resistance ◽  
Smart Materials ◽  
High Performance ◽  
Building Materials ◽  
Protective Coatings ◽  
Properties Of Coatings ◽  
Performance Properties ◽  
Aqueous Dispersions ◽  
Advantages And Disadvantages ◽  
Film Forming

The current state of development of the economy of the Russian Federation causes the appearance of a number of urgent problems related to improving production and increasing the level of environmentally safe products, in particular paints and varnishes combined with high performance properties of coatings based on them. In this regard, the advantages and disadvantages of aqueous dispersions based on polymers in the presence of various modifiers that are widely used in the paint and varnish industry were analyzed. This article discusses the problem of stability conditions for mixed materials of epoxy-acrylic type and the establishment of a relationship between the composition of the film-forming base and the performance properties of coatings. The purpose of this study is to create new water-dispersion paints and varnishes based on mixed epoxy-acrylic film-formers for coatings with increased hardness, wear resistance, elasticity and adhesion. The analysis of the main types of water-based film-forming agents is carried out. It is proposed to use mixed systems of film-formers based on epoxy-acrylic dispersions. It was established by standard methods that by combining dispersions of acrylic and epoxy types it is possible to achieve a significant increase in the wear resistance of the compositions (almost 2 times) in comparison with the wear resistance of materials based on acrylic. The adhesion of coatings to substrates of various nature (except for brick) increases with an increase in the content of the epoxy component. In terms of performance, acrylic epoxy can be more effective than acrylic and can be used in humid environments. An increase in the performance properties of these materials in comparison with acrylate systems has been confirmed. It should be noted that an additional task in the development of any building materials is affordability. It is known that not all dispersions are cheap, for example, in the presence of silicone polymers, dispersions are expensive, so they are used only when necessary. To improve operational properties and reduce the cost of protective coatings, we proposed using composite materials, which included styrene-acrylic and epoxy aqueous dispersions. In the future, it is planned to create “smart” materials whose properties will depend on functional fillers.

Abrasive wear of polymer/steel gear drives

2008 ◽  
Vol 4 (1) ◽  
pp. 1-26
Author(s):  
Gábor Kalácska
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Material Selection ◽  
Solid Particles ◽  
Soil Types ◽  
General View ◽  
Modern Engineering ◽  
Clean Environment ◽  
Engineering Polymers ◽  
Plastic Gears

Research was performed on the friction, wear and efficiency of plastic gears made of modern engineering polymers and their composites both in a clean environment (adhesive sliding surfaces) and in an environment contaminated with solid particles and dust (abrasive), with no lubrication at all. The purpose is to give a general view about the results of abrasive wear tests including seven soil types as abrasive media. At the first stage of the research silicious sand was applied between the meshing gears and the wear of plastic and steel gears was evaluated and analyzed from the point of different material properties (elongation at break, hardness, yield stress, modulus of elasticity) and its combinations. The different correlations between the experienced wear and material features are also introduced. At the second stage of the project the abrasive sand was replaced with different physical soil types. The abrasive wear of gears is plotted in the function of soil types. The results highlight on the considerable role of physical soil types on abrasive wear resistance and the conclusions contain the detailed wear resistance. The results offer a new tribology database for the operation and maintenance of agricultural machines with the opportunity of a better material selection according to the dominant soil type. This can finally result longer lifetime and higher reliability of wearing plastic/steel parts.

BÖHLER K100

Alloy Digest ◽  
2020 ◽  
Vol 69 (3) ◽  
Keyword(s):  
Wear Resistance ◽  
Physical Properties ◽  
Abrasive Wear ◽  
Tool Steel ◽  
Cold Work ◽  
Abrasive Wear Resistance ◽  
High Carbon ◽  
High Chromium ◽  
Cold Work Tool Steel

Abstract Böhler K100 is a high-carbon, high-chromium (12%), alloy cold-work tool steel that is suitable for medium run tooling in applications where a very good abrasive wear resistance is needed but where demands on chipping resistance are small. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming and machining. Filing Code: TS-788. Producer or source: voestalpine Böhler Edelstahl GmbH & Co.

SANDVIK APM 2730

Alloy Digest ◽  
2019 ◽  
Vol 68 (4) ◽  
Keyword(s):  
Wear Resistance ◽  
Compressive Strength ◽  
Physical Properties ◽  
Abrasive Wear ◽  
Tool Steel ◽  
High Speed ◽  
Heat Treating ◽  
Abrasive Wear Resistance ◽  
Steel Company ◽  
High Compressive Strength

Abstract Sandvik APM 2730 is a powder metallurgical alloyed hot-isostatic-pressed high-speed tool steel with abrasive wear resistance and high-compressive strength. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on heat treating and machining. Filing Code: TS-763. Producer or source: Sandvik Steel Company.

BÖHLER K107

Alloy Digest ◽  
2020 ◽  
Vol 69 (9) ◽  
Keyword(s):  
Wear Resistance ◽  
Physical Properties ◽  
Abrasive Wear ◽  
Cold Work ◽  
Heat Treating ◽  
Abrasive Wear Resistance ◽  
Tungsten Alloy ◽  
High Carbon ◽  
Cold Work Tool Steel ◽  
Very High

Abstract Böhler K107 is a high-carbon (2.1%), 12% chromium. 0.7 % tungsten, alloy cold-work tool steel that is used in applications where a very high abrasive wear resistance is needed, but where demands on chipping resistance are small. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming and heat treating. Filing Code: TS-799. Producer or source: voestalpine Böhler Edelstahl GmbH&Co KG.

Increasing in wear resistance of excavating machine elements

2020 ◽  
pp. 306-308
Author(s):  
V.S. Bochkov
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Thermomechanical Treatment ◽  
Cold Work ◽  
Hadfield Steel ◽  
Outer Side ◽  
Viii And Ix ◽  
Machine Elements ◽  
The Impact

The relevance of the search for solutions to increase the wear resistance of bucket teeth of excavating machine type front shovel is analyzed. The reasons for the wear of the teeth are considered. It is determined that when excavating machines work for rocks of VIII and IX categories, impact-abrasive wear of the inner side of the teeth and abrasive external wear occurs. It is proved that the cold-work hardening of Hadfield steel (the teeth material), which occurs during the excavating machine teeth work in the rocks of VIII and IX categories, reduces the impact-abrasive wear rate on the inner side of the teeth and does not affect the abrasive wear of the outer. The methods for thermomechanical treatment of the outer side of the excavating machine tooth is proposed. It can increase the wear resistance of Hadfield steel (110G13L) up to 1.7 times and lead to the self-sharpening effect of the tooth due to equalization of the wear rate of the outer and inner parts of the tooth. The efficiency factor of thermomechanical treatment to reduce the of abrasive wear rate of Hadfield steel is experimentally proved.

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