Results of research on wear resistance of structural materials

2020 ◽  
pp. 172-178
Author(s):  
Н.Г. Серёгин ◽  
В.Г. Исаев
Keyword(s):  
Mathematical Model ◽  
Wear Resistance ◽  
Dynamic Loading ◽  
Static Loading ◽  
Friction Pair ◽  
Structural Materials ◽  
Comparative Tests ◽  
Experimental Installation ◽  
Dynamic Wear

Описана конструкция экспериментальной установки для проведения сравнительных испытаний износостойкости различных пар трения конструкционных материалов. Представлены результаты сравнительных испытаний износостойкости двух пар трения при статическом нагружении и определена лучшая из них. Приведены результаты испытаний износостойкости лучшей пары трения при динамическом нагружении. Разработана математическая модель динамического изнашивания лучшей пары трения конструкционных материалов. The design of an experimental installation for conducting comparative tests of the wear resistance of various friction pairs of structural materials is described. The results of comparative tests of the wear resistance of two friction pairs under static loading are presented and the best of them is determined. The results of tests of the wear resistance of the best friction pair under dynamic loading are presented. A mathematical model of dynamic wear of the best friction pair of structural materials is developed.

Analysis of Wear-Resistant Materials of Mixer - Pneumosuperchargers Blades Operating under Conditions of Abrasive Wear

2021 ◽  
Vol 316 ◽  
pp. 893-898
Author(s):  
Natalya Gabelchenko ◽  
Artem Belov ◽  
Artem Kravchenko ◽  
Oleg Kryuchkov
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Wear Resistance ◽  
Chemical Composition ◽  
Abrasive Wear ◽  
Abrasive Medium ◽  
Wear Resistant ◽  
Comparative Tests ◽  
Before And After ◽  
110G13l Steel

We conducted comparative tests of the wear resistance of metals operating under abrasive conditions. Samples were cut from the working parts of mixer-pneumosuperchargers. The chemical composition and mechanical properties were determined. To compare samples under abrasive wear conditions, we designed and assembled a carousel installation. The principle of its operation is based on mixing the abrasive medium by the samples being studied with a given speed. Wear resistance was evaluated by weight loss by samples after several test cycles. To determine changes in the structure of the metal during abrasive wear, metallographic studies of the samples were carried out before and after the tests. It is shown that the best complex of service and mechanical properties is possessed by 110G13L steel.

scholarly journals About the mechanism for reducing the adhesion wear of the copper friction pair in the inert atmosphere by the nitrogen ions implantation method

2020 ◽  
pp. 72-79
Author(s):  
V.P. Sergeev ◽  
◽  
M.P. Kalashnikov ◽  
A.R. Sungatulin ◽  
O.V. Sergeev ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Friction Pair ◽  
High Energy ◽  
Inert Atmosphere ◽  
Solid Solution Hardening ◽  
Internal Stresses ◽  
Maximum Increase ◽  
Energy Beam ◽  
Nitrogen Ions

The mechanisms of increasing the resistance of copper samples treated with a high-energy beam of nitrogen ions to adhesive wear during friction together with a copper counterbody in an argon atmosphere are studied. It was shown that the increase in wear resistance is complex and is associated with the action of mechanisms such as solid-solution hardening, grinding of copper grains, precipitation of the finely dispersed CuN3 phase, increase in the density of dislocations and internal stresses of the second kind in the surface layer . The maximum increase in wear resistance and microhardness (~ 4 and ~ 2.6 times, respectively, compared with the original copper) is observed about ion fluence of ~ 9×1017 ion/cm2. A further increase in fluencies leads to a decrease in wear resistance and microhardness due to the enlargement of the pores formed in the surface layer of copper as a result of implantation of nitrogen ions.

Experimental study on the influence of friction pair material hardness on the tribological behaviors of water lubricated thrust bearings

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xingxin Liang ◽  
Zhiyong Yang
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Abrasive Wear ◽  
Friction Pair ◽  
Aluminum Bronze ◽  
Heavy Load ◽  
Content Type ◽  
Thrust Bearings ◽  
Tribological Behaviors ◽  
Polymer Bearing

Purpose This paper aims to confirm that increasing the hardness of thrust collars can improve the load carrying capacity (LCC) and wear resistance of water lubricated thrust bearings (WTBs) made of polymers paired with non-polymeric thrust collars, and to design a WTB with high LCC and durability for a shaftless pump-jet propulsor of an autonomous underwater vehicle. Six kinds of WTBs were manufactured by matching aluminum bronze, stainless steel and silicon nitride with two different polymer bearing materials. Their tribological behaviors were tested and compared. Design/methodology/approach The tribological behaviors of the WTBs made with different materials were investigated experimentally on a specially designed test rig. Findings Aluminum bronze is not suitable for crafting thrust collars of heavy load WTBs due to severe abrasive wear. Two body abrasive wear first occurred between the thrust collar and the polymer bearing. Next, aluminum bronze wear particles were produced. The particles acted between the two materials and formed three body abrasive wear. Stainless steel/polymer bearings showed better wear resistance while Si3N4/polymer bearings were the best. Improving the hardness of thrust collars is significant to the LCC and service life of WTBs. Originality/value The wear mechanism of WTBs under heavy load conditions was revealed. Improving the hardness of the thrust collar was confirmed to be a preferable method to improve the wear resistance and LCC of WTBs. The results of this study may provide an important reference for the selection of water lubricated materials and the design of heavy load WTBs.

scholarly journals Fracture Resistance of Zirconia Oral Implants In Vitro: A Systematic Review and Meta-Analysis

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 562 ◽  
Author(s):  
Annalena Bethke ◽  
Stefano Pieralli ◽  
Ralf-Joachim Kohal ◽  
Felix Burkhardt ◽  
Manja von Stein-Lausnitz ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Static Loading ◽  
Fracture Resistance ◽  
Tetragonal Zirconia ◽  
Present Review ◽  
Hydrothermal Aging ◽  
Oral Implants ◽  
Electronic Screening ◽  
The Impact ◽  
Zirconia Implants

Various protocols are available to preclinically assess the fracture resistance of zirconia oral implants. The objective of the present review was to determine the impact of different treatments (dynamic loading, hydrothermal aging) and implant features (e.g., material, design or manufacturing) on the fracture resistance of zirconia implants. An electronic screening of two databases (MEDLINE/Pubmed, Embase) was performed. Investigations including > 5 screw-shaped implants providing information to calculate the bending moment at the time point of static loading to fracture were considered. Data was extracted and meta-analyses were conducted using multilevel mixed-effects generalized linear models (GLMs). The Šidák method was used to correct for multiple testing. The initial search resulted in 1864 articles, and finally 19 investigations loading 731 zirconia implants to fracture were analyzed. In general, fracture resistance was affected by the implant design (1-piece > 2-piece, p = 0.004), material (alumina-toughened zirconia/ATZ > yttria-stabilized tetragonal zirconia polycrystal/Y-TZP, p = 0.002) and abutment preparation (untouched > modified/grinded, p < 0.001). In case of 2-piece implants, the amount of dynamic loading cycles prior to static loading (p < 0.001) or anatomical crown supply (p < 0.001) negatively affected the outcome. No impact was found for hydrothermal aging. Heterogeneous findings of the present review highlight the importance of thoroughly and individually evaluating the fracture resistance of every zirconia implant system prior to market release.

scholarly journals Failure Behavior and Energy Storage and Release of Hard Coal under Different Static and Dynamic Loading States

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
XianJie Hao ◽  
GuangYao Pan ◽  
Chaoxing Ma ◽  
Yingnan Wei ◽  
Zeyu Chen
Keyword(s):  
Dynamic Loading ◽  
Coal Mine ◽  
Static Loading ◽  
Dynamic Compression ◽  
Hard Coal ◽  
Failure Behavior ◽  
Static Compression ◽  
Energy Rate ◽  
Energy Accumulation ◽  
Static Tensile

The study of the energy accumulation and rate of release in hard coal under dynamic, static, and coupled dynamic-static loading and its failure mode is of significance when studying the mechanism underpinning coal mine dynamic disasters such as rock burst, coal, and gas outburst. In this paper, four experimental methods (uniaxial compression, Brazilian splitting, and coupled dynamic-static tensile and coupled dynamic-static compression) were used to analyze the energy accumulation, energy rate of release, and failure modes of this type of hard coal under different loading conditions. It was concluded that (1) the energy accumulation and rate of releases of this type of hard coal under static compression are 17.63–179.90 times and 18.57–13157.89 times those under static tension; the energy accumulation and rate of releases in dynamic compression are 2.11–248.53 and 0.23–48 times those under dynamic tension, respectively. (2) During dynamic loading, the ratio of compressive energy accumulation to tensile energy accumulation is reduced by 1.6 times compared with static loading, and the ratio of compressive energy release to tensile energy rate of release is decreased by 363.84 times compared with static loading. (3) The energy accumulation and rate of releases of this type of hard coal for dynamic tensile are, respectively, 2.64–17.42 and 1.07–5.26 times those under static tensile load; the energy accumulation under dynamic compression is greater than that under static compression, being 0.24–15.04 times that under static compressive, but the energy rate of release under dynamic compression is 0.0003–0.56 times that under static compression. (4) The greater the prepeak energy accumulation, the greater the degree of damage of the coal sample at each stage, and also the higher the degree of fragmentation after the failure. The research results play an important guiding role in further understanding the mechanism of coal mine dynamic disasters.

scholarly journals Technology to Increase Hydrocarbon Wear Resistance of Friction Units of Hydrogen Aggregates

2019 ◽  
Vol 297 ◽  
pp. 09001 ◽  
Author(s):  
Mikhail Shalygin ◽  
Sergei Kuznetsov
Keyword(s):  
Wear Resistance ◽  
Steel Surface ◽  
Friction Pair ◽  
Dehydration Process ◽  
Diffusion Capacity ◽  
Friction Units ◽  
Surface Irregularities ◽  
Friction Surfaces ◽  
Technological Methods ◽  
Wear Tests

The causes of hydrogen wear of the friction surfaces involved in hydrocarbon transfer and distillation processes are considered. Some technological methods for reducing the hydrogen wear of parts and friction units operating in hydrocarbon environment are given. A comprehensive technology for obtaining the properties of the surface layer is proposed, which provides an increase in the wear resistance of a friction pair and smoothing the surface roughness. The increase in wear resistance is based on several mechanisms: (1) decreasing biographical hydrogen due to the dehydration process; (2) smoothing surface irregularities by saturating the surface with silicon; (3) reducing the diffusion capacity of the steel surface caused by diffusion siliconizing; (4) reducing grain size of the material. Comparative wear tests were carried out, which showed the effectiveness of the proposed methods.

scholarly journals Performance of Self-Compacted Reactive Powder Concrete Slab Under Harmonic Dynamic Loading

2019 ◽  
Vol 26 (1) ◽  
pp. 89-99
Author(s):  
Mohammad Makki Abbass Bilal ◽  
Mohamad Adnan Mohamad
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Loading ◽  
Static Loading ◽  
Concrete Slab ◽  
Reactive Powder Concrete ◽  
Concrete Slabs ◽  
Dynamic Resistance ◽  
Structural Element ◽  
Reinforced Concrete Slabs ◽  
Reactive Powder

Many types of loading the structure must sustain in addition to dead and live loads according to the function of structural element type that must be taken in analysis.  Dynamic resistance to loading of reinforced concrete slabs using self-compact reactive powder concrete, with different boundary conditions at the sides in addition of static loading was studied. The reinforced concrete slabs were designed under static load according to ACI-318R-2014 and then the adequacy was checked under harmonic dynamic loading. The static loading consists of dead load and residential live load considering according to ASCE-07-2010. Modeling analysis was performed to determine the eigenvalues and eigenvectors values and then frequency response analyses of the slab by finite elements method that adopted for analysis. The results indicated that in case of self-compacted reactive powder concrete rather than normal concrete gave deflection less and also there was a different result of deflection according the type of slab boundary condition supports.

scholarly journals Studying wear resistance of steel friction pairs under high contact pressure in water-abrasive medium

2019 ◽  
Vol 2019 (4) ◽  
pp. 23-29
Author(s):  
Валерий Петровский ◽  
Valeriy Petrovskiy ◽  
Анатолий Рубан ◽  
Anatoliy Ruban
Keyword(s):  
Heat Treatment ◽  
Plastic Deformation ◽  
Wear Resistance ◽  
Friction Pair ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Abrasive Medium ◽  
Operational Tests ◽  
A Chain ◽  
Efficiency And Reliability

The paper is focused on the problem of the service life of the dredger chain, which largely depends on the efficiency and reliability of the hinge joint, when a mineral abrasive gets into the structural gap resulting in rapid wear of the joint under high dynamic loads. There has been developed a science-based technology of repairing parts of the assembly, without reducing the resource, from cheap and accessible (non-deficient) materials, taking into account modern technical and economic requirements, on samples. Wear resistance of samples of friction pairs has been defined in terms of a chain operating model. The research method is based on comparing the wear rate of samples in a pair made of steel 110Mn13 (sleeve - pin), 110Mn13 and 38CrNi3M (sleeve - pin), according to the standard technologies and taken as a reference, with pairs made of steel 110Mn13, C45K, facing with wire SV08A, electrodes E50A – UONI 13/55 and E – 190Cr5Si7 – LEZ – T – 590 – NG after heat treatment, chemical and heat treatment, surface plastic deformation. Samples were tested in the water-abrasive environment with a load of 6615 N (675 kgf). The wear resistance parameters were determined as following: 1) reference pairs of steel 110Mn13 (bushing-pin) and 110Mn13 (bushing), 38CrNi3Mo (pin); 2) pairs of steel 110Mn13 (bushing) and facing with wire SV08A (pin); 3) pairs of steel 110Mn13 (bushing) and cladding with electrodes E–190Cr5Si7–LEZ –T–590– NG (pin); 4) pairs of steel C45K (bushing) and cladding with E –190Cr5Si7 – LEZ – T – 590 – NG electrodes (pin); 5) pairs of steel C45K (bushing) and clad-ding with E50A – UONI 13/55 electrodes (pin). A graph of dependence of the bushing and pin wear on the relations of initial hardness and structures of friction pair has been built. It is recom-mended to restore the pin with wear-resistant electrodes E – 190Cr5Si7 – LEZ – T – 590 – NG paired with 110Mn13 steel bushing with surface plastic deformation. The wear resistance of a pair, with a different combination of structures, does not depend on the ratio of hardness of Hsl / Hfin. The materials of the pair worn within the reference samples can be recommended for the operational tests.

scholarly journals Dynamic Processes of Loader Cranes Manipulators with Excessive Backlashes and Elastic Damping in Their Hinges

2019 ◽  
Vol 64 (1) ◽  
pp. 7-14
Author(s):  
Alexander V. Lagerev ◽  
Igor A. Lagerev
Keyword(s):  
Mathematical Model ◽  
Dynamic Loading ◽  
Structural Design ◽  
Impact Load ◽  
Dynamic Processes ◽  
Effective Solution ◽  
Complete Elimination ◽  
Quantitative Characteristics ◽  
Motion Parameters ◽  
Oscillatory Processes

This research is aimed at developing a mathematical model and the methodology for computer simulation of hydraulically driven manipulators of mobile cranes having excessive backlashes in cylindrical joints. The authors proposed a structural design and considered the mechanism of reducing the additional impact load in the hinges by means of elastic damping of oscillatory processes. This method allows estimating the degree of influence of the backlash and stiffness of the elastic damper on the change in the quantitative characteristics of the dynamic loading of the manipulators metalwork and the motion parameters of the transported load. While in operation, the excessive backlashes may cause an increase in the level of dynamic loading of manipulators up to 2 times or more. However, the rational choice of the elastic dampers stiffness allows an effective solution to this problem to the point of complete elimination of the additional impact load.

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