scholarly journals Researched the wear resistance of hardened plowshares by electroarc and spot welding

2019 ◽  
pp. 189-196
Author(s):  
M. Vаsylenko ◽  
D. Buslаiev ◽  
O. Kаlinin ◽  
Yu. Kononogov
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Spot Welding ◽  
Field Tests ◽  
Sandy Soils ◽  
Clay Soils ◽  
Basic Principles ◽  
Data Field ◽  
Different Types ◽  
Analytical Processing

Purpose. The researched of the wear resistance of hardened plowshares by electroarc and abrasion-resistant electrodes, when they are used in soils of different types. Methods. Conducting and planning an experiment, mathematical statistics and analytical processing of experimental data, field tests of experimental plowshares using the basic principles of the theory of friction and abrasive wear. Results. The characteristic defects of shares operating in different types of soils are determined. According to the proposed hardening technology, the wear rate of experimental shares is reduced. Conclusions 1.It has been established that the nature of the parts of tillage machines wear is significantly different when operating on various types of soils. 2.It was found that the wear rate of hardened plowshares for sandy soils is 1.2–1.6 times less than that of serial parts; hardened plowshares for clay soils also have a wear rate of 1.2–1.3 times less than serial ones. Keywords: exploitation, hardfacing, plowshares, soils of different types, wear, wear resistance.

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.

Improving the efficiency of hardening of tillage machine working bodies by arc surfacing using wear-resistant rollers

2020 ◽  
pp. 176-185
Author(s):  
Dmitriy B. Slinko ◽  
Vyacheslav A. Denisov ◽  
Dmitriy A. Dobrin ◽  
Andrey V. Afanas’yev ◽  
Pavel M. Kislov
Keyword(s):  
Wear Resistance ◽  
Operating Time ◽  
Field Tests ◽  
Electric Arc ◽  
Cutting Edge ◽  
Linear Size ◽  
Research Purpose ◽  
Cored Wire ◽  
Wear Resistant ◽  
Working Bodies

Reducing operating costs during soil processing and increasing the wear resistance of parts and components is an important condition for reducing the cost of agricultural products, increasing its efficiency and competitiveness. The development of materials with increased wear resistance and new effective technologies for strengthening working bodies in their manufacture is now becoming an urgent task. (Research purpose) The research purpose is increasing the wear resistance of the working bodies of soil-processing machines by electric arc surfacing. (Materials and methods) During the experimental study, it has been performed testing of modes and surfacing of a pilot batch of working bodies from Kverneland for field tests in VIM on an automated installation for electric arc surfacing. Authors used eutectic CastolinEnDotec DO*30 powder wire with a diameter of 1.2 millimeters and a boron content of up to 4 percent for surfacing wear-resistant rollers, which allows to obtain wear-resistant rollers with a hardness of up to 65 HRC without pores and cracks. (Results and discussion) It has been revealed that hardened ploughshares that have passed field tests are subject to lower wear rates compared to non-hardened ones. It was found that when operating time is 24.785 hectares per ploughshare, the wear of the linear size of the cutting edge along the width of hardened ploughshares is on average up to 10-11 millimeters less than that of non-hardened ones. It was found that when processing 228 hectares, the wear of the linear size of the cutting edge along the width of hardened bits is on average up to 9-10 millimeters less than that of non-hardened ones. (Conclusions) The technology of surfacing with intermittent wear-resistant rollers provides an increase in the efficiency of hardening of Kverneland working bodies according to the criterion of wear resistance by an average of 20-30 percent. The adjusted technological parameters of the surfacing process will reduce the wear rate and increase the service life of the blade part of the working bodies, as well as reduce the amount of surfaced material by an average of 60 percent. The continuation of work on strengthening the working bodies should be aimed at changing the surfacing scheme and choosing a cheaper domestic cored wire.

scholarly journals ID Learning Unit: Understanding and Interpreting Testing for Clostridium difficile

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Daniel A. Solomon ◽  
Danny A. Milner
Keyword(s):  
Clinical Practice ◽  
Clostridium Difficile ◽  
Basic Principles ◽  
Multiple Tests ◽  
Molecular Tests ◽  
Different Types

Abstract Understanding and interpreting the molecular tests for Clostridium difficile is challenging because there are several different types of assays and most laboratories combine multiple tests in order to assess for presence of disease. This learning unit demonstrates the basic principles of each test along with its strengths and weaknesses, and illustrates how the tests are used in clinical practice.

Microstructure and Grain Abrasion Properties of Cr3C2-NiCr Coating Prepared by Laser Cladding Method

2012 ◽  
Vol 271-272 ◽  
pp. 3-7
Author(s):  
Long Wei ◽  
Zong De Liu ◽  
Xin Zhi Li ◽  
Ming Ming Yuan ◽  
Cheng Yuan Zhong
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Laser Cladding ◽  
Micro Hardness ◽  
High Quality ◽  
Wear Resistant ◽  
Hardness Tester ◽  
Technology Analysis ◽  
Main Component

Cr3C2-NiCr has high quality of wear resistant properties and is widely used in abrasive environment. In this paper, Cr3C2-NiCr coating was prepared on 45 steel by laser cladding technology. Analysis and research of the coatings were achieved by SEM and XRD to determine the main component and the different region on coatings. The hardness and the element component were investigated by micro-hardness tester and EDS. Abrasion tests were performed to contrast the wear resistance of two materials. The results indicate that the hardness of the coatings is nearly 3 times as the substrate. The coatings are well combined with the substrate and the phase of Cr3C2 has a large proportion in the coatings. Abrasion tests show that the average of wear rate on substrate is 5.2 times as the coatings.

Evaluation of changes in mechanical properties of O-ring in one-piece and two-piece ball retained implant-supported overdentures: A three-year retrospective study.

2021 ◽  
Author(s):  
Fathima Banu Raza ◽  
Anand Kumar
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Retrospective Study ◽  
Statistical Analysis ◽  
Wear Rate ◽  
Digital Camera ◽  
Maximum Displacement ◽  
Pin On Disc ◽  
The One ◽  
Insight Into

The o-rings in ball retained overdentures deteriorate with time and need replacement to restore the retentive quality. We evaluated retrospectively the mechanical properties of o-rings after 3 years in function in one and two-piece implant-supported overdentures. The o-rings were retrieved from one-piece (Myriad snap, Equinox-Straumann, 3.3 x 13mm) and two-piece (Neo Biotech, 3.3 x 13mm) implant-supported overdenture patients. A total of 16 pairs of matrices were tested for wear, type of damage and elasticity using Pin on Disc method, USB Digital Camera in 30x zoom and Universal Tensile Machine respectively. The statistical analysis for independent groups were done with the Mann-Whitney U test. Assessment of used O-rings showed 84% more wear in the two-piece system with an abrasive type of damage while 46% wear in the one-piece system with a compressive type of damage. The o-rings in one-piece system showed increase in elongation and maximum displacement to 2% and 7% respectively, while two-piece system showed decrease in elongation and maximum displacement by 13% and 6% respectively. In one-piece system, the loss of retention was more with slow wear rate and in two-piece system, the wear resistance of O-rings decreased due to increased stiffness. Further studies to evaluate the changes in O-ring with increased sample size and at interval 1 year will pave way for insight into the progressive changes in the mechanical properties of an O-ring.

Effect Multiple Addition (TiO2 and Fly Ash) on Wear Behavior and Hardness of 2024 Al Alloy

2021 ◽  
Vol 1039 ◽  
pp. 201-208
Author(s):  
Ruaa A. Salman ◽  
Naser K. Zedin
Keyword(s):  
Wear Resistance ◽  
Fly Ash ◽  
Wear Rate ◽  
Wear Behavior ◽  
Weight Percent ◽  
Al Alloy ◽  
Sliding Speed ◽  
Multiple Addition

This research is devoted to study the effect of addition (2%) TiO2 with different weight percent of fly ash particulate (0, 2, 4, 6%) to 2024 Al alloy on the wear behavior and hardness. The alloy was fabricated by the liquid metallurgy method. The results founds that the wear rate decreased from 0.55 with 0% fly ash to 0.18 at addition percentage of 6% fly ash. Also, the results reveal increasing the samples wear rate with increasing the load and loaded time. The rate of wear was decreased with increasing the sliding speed. Also, the values of hardness increased from 120VH to 160VH with rising the fly ash from 0% to 6%. Keywords: Fly Ash addition, TiO2, 2024 Al Alloy, Wear Resistance, Hardness.

scholarly journals Influence of nano-SiO2 on the bonding strength and wear resistance properties of polyurethane coating

2019 ◽  
Vol 26 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Fangfang Wang ◽  
Lajun Feng ◽  
Huini Ma ◽  
Zhe Zhai ◽  
Zheng Liu
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Composite Coating ◽  
Network Structure ◽  
Bonding Strength ◽  
Coating Layer ◽  
Steel Substrate ◽  
Polyurethane Coating ◽  
Nano Sio2

Abstract To improve the wear resistance of polyurethane (PU) coating and its adhesion to the steel substrate, a series of simple and practicable techniques were designed to mix nano-SiO2 with PU powder to cast a coating layer onto the steel. When the addition of nano-SiO2 was small, a network structure of PU-SiO2 was produced. It improved the wear resistance of the composite coating and its adhesion to the steel substrate. When the addition of nano-SiO2 was excessive, agglomerated nano-SiO2 particles not only affected the bond between the PU resin and the steel substrate but also became abrasive materials, intensifying the abrasion of the composite coating during friction. It resulted in lower bonding strength and poorer wear resistance of the composite coating. The wear rate and friction coefficient of 2 wt.% SiO2/PU composite coating were 1.52×10−6 cm3/min N and 0.31, respectively. Its wear resistance was about 10 times as high as that of the pure PU coating. Furthermore, a simple and practicable installation was designed to test the bonding strength between the coating and the steel substrate. The bonding strength between 2 wt.% SiO2/PU composite coating and the steel substrate was 7.33 MPa, which was 39% higher than that of the pure PU coating.

scholarly journals Deep foundations of happiness. Principal fundamentals of different types of understanding happiness

2021 ◽  
Vol 76 (1) ◽  
pp. 23-29
Author(s):  
L. Samarska ◽  
◽  
N.M. Sas ◽  
Keyword(s):  
Time Management ◽  
Well Being ◽  
Free Play ◽  
Deep Foundations ◽  
Subjective Well Being ◽  
Physiological Basis ◽  
Basic Principles ◽  
Theoretical Approaches ◽  
Different Types ◽  
Definition Of

The choice of the article’s topic is conditioned by the necessity to develop happiness management (such as knowledge management, time management, etc.). With considerable attention to the definition of “happiness”, the analysis of recent publications reveals that it is crucial to understand the deep foundations of happiness, create a typology, reveal the basic principles of different types of understanding of happiness, which was chosen as the topic research. Theoretical approaches to the definition of “happiness” are chosen sociology of imagination of G. Durand, the theory of archetypes of C. Jung, and the theory of images and dreams of G. Bachelard. In the context of this system of views, the idea of happiness is the result of a free play of the imagination, which, while being on the path from past to future, is transformed, revealed, comes accurate as a result of previous collective and individual intermediate ideas, and is enriched and concretised by individual people, social groups, individuals. The mythos of happiness across nations and people differs in the way, method, and tools of individuation, the discovery of the Self. The anthropological tract of happiness has an end to its existence. It is determined by the cessation of existence, the life of nations and individuals. The desire to experience pleasure (according to Freud), the desire to rise (according to Durand) are reflexive, which determines the physiological basis of happiness. Representations of happiness determine priorities, coordinate the direction of thinking, actions, reactions to external circumstances, and choose ways to achieve happiness. This is done through the transcendental function (according to Jung) – a psychological function that arises from the connection of the content of the unconscious with the content of consciousness. Achieving happiness allows one to strengthen the subjectivity and reveal their uniqueness, which allows them to identify typological features (archetypes) of behavioural reactions of people based on individual and group ideas about happiness. The authors reveal the basic foundations of such archetypes of happiness as hedonism, eudemonia, “rat racing”, nihilism, subjective well-being.

scholarly journals State-of-the-Art-Review of Collapsible Soils

2000 ◽  
Vol 5 ◽  
pp. 115 ◽  
Author(s):  
A. A. AL-Rawas
Keyword(s):  
Field Tests ◽  
Clay Content ◽  
Field Testing ◽  
Dry Density ◽  
Foundation Design ◽  
Treatment Methods ◽  
Collapse Potential ◽  
Collapsible Soils ◽  
Different Types ◽  
Compaction Control

Collapsible soils are encountered in arid and semi-arid regions. Such soils cause potential construction problems due to their collapse upon wetting. The collapse phenomenon is primarily related to the open structure of the soil. Several soil collapse classifications based on parameters such as moisture content, dry density, Atterberg limits and clay content have been proposed in the literature as indicators of the soil collapse potential. Direct measurement of the magnitude of collapse, using laboratory and/or field tests, is essential once a soil showed indications of collapse potential. Treatment methods such as soil replacement, compaction control and chemical stabilization showed significant reduction in the settlement of collapsible soils. The design of foundations on collapsible soils depends on the depth of the soil, magnitude of collapse and economics of the design. Strip foundations are commonly used when collapsing soil extends to a shallow depth while piles and drilled piers are recommended in cases where the soil extends to several meters. This paper provides a comprehensive review of collapsible soils. These include the different types of collapsible soils, mechanisms of collapse, identification and classification methods, laboratory and field testing, treatment methods and guidelines for foundation design.

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