scholarly journals Assessment of friction pair elements condition based on changes in the geometric surface structure isotropicity degree

2019 ◽  
Vol 302 ◽  
pp. 01015 ◽  
Author(s):  
Maciej Matuszewski ◽  
Małgorzata Słomion ◽  
Adam Mazurkiewicz ◽  
Danil Yu. Pimenov
Keyword(s):  
Weight Loss ◽  
Surface Layer ◽  
Surface Structure ◽  
Friction Pair ◽  
Tribological Characteristics ◽  
Roughness Parameters ◽  
Functional Characteristics ◽  
Tribological Tests ◽  
Functional Features ◽  
Geometric Surface

This paper regards the possibility of using the degree of the surface isotropicity to assess the condition of the surface layer friction pair elements. The analysis is based on certain changes in operational and technological surface layer. The methods of constituting the surface layer have been characterized due to the features of geometric surface structure as well as the problem of assessing the condition of surface in terms of functional features and tribological characteristics. The evaluation of the occurring changes in the surface layer have been conducted by performing tribological tests and for descript condition of surfaces the degree of surface isotropicity and weight loss of specimens have been adopted. Whereas the assessment of technological state of the surface layer has been carried out for the surface after its coating. Based on the analysis, it has been found that the use for assessment the condition of surface layer and the degree of the surface isotropicity are useful and it is an alternative way or supplement to classical adoption of a properly selected set of roughness parameters to evaluate the potential functional characteristics of friction couples surfaces.

scholarly journals Mass wear application of cooperated elements for evaluation of friction pair components condition

2021 ◽  
Vol 351 ◽  
pp. 01006
Author(s):  
Maciej Matuszewski ◽  
Małgorzata Słomion ◽  
Adam Mazurkiewicz ◽  
Andrzej Wojciechowski
Keyword(s):  
Surface Layer ◽  
Surface Structure ◽  
Friction Pair ◽  
Experimental Tests ◽  
Wear Process ◽  
Machine Elements ◽  
Conformal Contact

In this study, the influence of the geometrical surface structure shape on wear process of friction pairs elements with conformal contact was analyzed. Characteristics of the machine elements surface layer were described with special distinction of importance of the surface structure directivity and isotropy in terms of the surface layer transformation. This work presents the results of experimental tests in which the following input factors were used: specimen and counter-specimen ridge angle of intersection (0°; 30°; 45°; 60°; 90°) and specimen and counter-specimen clamp (1.0; 1.5; 2.0 MPa). The changes of the surface layer were recorded as a function of a specimen mass changes. Based on the conducted research, it was found that the ridge angle of intersection on the specimen and counter-specimen has a significant impact on the wear process intensity. The changes were uttermost for 0° angle and slightest for 9°. It was also found that the observed changes have a larger gradient for higher specimen load values. Thus, the significance of the geometrical surface structure directivity influence on the friction pair elements wear process intensity was confirmed.

THE INFLUENCE OF COOLING AND LUBRICATION LIQUID QUANTITY ON THE ISOTROPY OF A MACHINE COMPONENT SURFACE DURING MACHINING

Tribologia ◽  
2016 ◽  
Vol 265 (1) ◽  
pp. 57-65
Author(s):  
Maciej MATUSZEWSKI ◽  
Jarosław MIKOŁAJCZYK ◽  
Tadeusz MIKOŁAJCZYK ◽  
Michał STYP-REKOWSKI
Keyword(s):  
Surface Structure ◽  
Geometric Structure ◽  
Machine Component ◽  
Roughness Parameters ◽  
Structure Characteristics ◽  
Cooling And Lubrication ◽  
Geometric Surface ◽  
Liquid Quantity ◽  
Lubrication Conditions

This paper presents an initial verification of the influence of a cooling- -lubrication liquid or its lack on the geometric surface structure of machine components undergoing the process of machining. It has been proposed to use the degree of isotropy of the finish surfaces, apart from commonly used roughness parameters, for the evaluation of changes in the quality of components machined in different cooling and lubrication conditions. In this study, the usefulness of the degree of isotropy for a description of the surface geometric structure characteristics has been verified.

BEARING CAPACITY OF THE SURFACE AFTER MACHINING WITH MINIMUM COOLING AND LUBRICATION

Tribologia ◽  
2018 ◽  
Vol 282 (6) ◽  
pp. 157-162
Author(s):  
Andrzej WOJCIECHOWSKI ◽  
Małgorzata SŁOMION ◽  
Maciej MATUSZEWSKI
Keyword(s):  
Bearing Capacity ◽  
Surface Structure ◽  
Negative Impact ◽  
Load Capacity ◽  
Functional Features ◽  
Cooling And Lubrication ◽  
Geometric Surface ◽  
Processing Fluid

The paper discusses the problem of surface bearing capacity and the parameters that characterize it in the context of the assessment of functional features. The result of the tests that are concerning the verification of the influence of minimal cooling and lubrication during processing on the constituted geometric surface structure described by the load capacity parameters are presented. On the basis of the obtained results, it was found that the minimum cooling and lubrication does not have a negative impact on the functional features, and they are even more advantageous than with the conventional processing fluid.

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

scholarly journals Functional Trait Responses to Strip Clearcutting in a Moso Bamboo Forest

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 793
Author(s):  
Yaxiong Zheng ◽  
Fengying Guan ◽  
Shaohui Fan ◽  
Yang Zhou ◽  
Xiong Jing
Keyword(s):  
Leaf Area ◽  
Functional Traits ◽  
Root Length ◽  
Fine Root ◽  
Root Traits ◽  
Moso Bamboo ◽  
Leaf Nitrogen Content ◽  
Dry Matter Content ◽  
Functional Characteristics ◽  
Functional Features

Functional characteristics reflect plant strategies and adaptability to the changing environment. Determining the dynamics of these characteristics after harvesting would improve the understanding of forest response strategies. Strip clearcutting (SC) of moso bamboo forests, which significantly reduces the cutting cost, has been proposed to replace manual selective harvesting. A comparison of restoration features shows that 8 m is the optimal cutting width. However, the precise response of functional features to the resulting harvest-created gap remains unclear. In this study, three SC plots were selected which was performed in February 2019, with three unharvested plots as a control (C). The study focused on 10 functional traits, including leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), nitrogen/phosphorus ratio (N:P), wood density (WD), fine root biomass (FRB), specific fine root length (SRL), and root length density (RLD). A one-way ANOVA was used to compare differences in functional traits and soil nutrients between treatments. Strip clearcutting significantly reduced the soil organic carbon (SOC) and total nitrogen (TN) contents (p < 0.05). In terms of functional characteristics, SC significantly decreased LA and increased LNC, LPC, and N:P (p < 0.05). However, SC had no significant effect on fine root traits (p > 0.05). This study highlighted that root trait, soil content of total phosphorus (TP) and total potassium (TK) returned to the level of uncut plots after a year’s recovery. The LPC, LNC, and N:P were negatively correlated with LA, and LDMC and WD were negatively correlated with SLA, while the effect of SC on fine root traits was limited (p > 0.05). Fine root traits (FRB, RLD, and SRL) were positively associated with SOC, TN, and TP, but negatively correlated with TK. The changes in soil nutrient content caused by the removal of biomass were normal. Increased light and the rapid growth of new trees will increase nutrient regressions; therefore, these results further confirm the feasibility of SC.

Unsicherheit von Rauheitskennwerten in der Praxis*/Uncertainty of roughness parameters in practice

2016 ◽  
Vol 106 (11-12) ◽  
pp. 823-829
Author(s):  
S. Rief ◽  
J. Prof. Seewig
Keyword(s):  
Surface Structure ◽  
Environmental Effects ◽  
Roughness Parameters ◽  
Measurement Devices ◽  
Surface Statistics

In der messtechnischen Praxis zeigt sich, dass Rauheitskennwerte unsicher sind. Dabei machen nicht die geläufigen Einflüsse wie das Messgerät oder die Umgebung den Hauptanteil der Unsicherheit aus, sondern die statistisch verteilte Struktur der Oberfläche. Dazu wurde eine Datenbank mit detaillierten Messungen von Zylinderlaufbahnen erstellt. Anhand der Auswertung vieler Messstrecken kann die Auswirkung der Statistik der Oberfläche auf verschiedene Rauheitskennwerte untersucht werden. &nbsp; In practical measurements, it is apparent that roughness parameters are uncertain. Main causes of uncertainty are not familiar sources such as measurement devices or environmental effects but the statistically distributed surface structure. As a demonstrator, a database with detailed measurements of cylinder working surfaces has been created. Based on the evaluation of many profiles, the influence of the surface statistics on roughness parameters can be investigated.

Development of Nano-Structured Aluminum Surfaces by LSM

2008 ◽  
Author(s):  
Taha Mattar ◽  
Ehab Abdel Rahman ◽  
Ahmed Abdel-Aziz ◽  
Haytham El-Gazzar
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Surface Structure ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting ◽  
Aluminum Surface ◽  
Yag Laser ◽  
Structured Surface ◽  
Aluminum Surfaces

Aluminum is one of most common metals in all advanced and modern scientific and technological applications including electrical, electronic, chemical, engineering, energy and medical fields. The performance of aluminum alloys determines to large extent the quality and economic status of the different processes. Aluminum surface structure determine its performance where nano sized grains and layer can improve aluminum properties and performance. In this work, the improvement of aluminum surface structure and formation of nano structured surface grains by laser surface melting (LSM) using Nd-YAG laser under argon atmosphere was investigated. Different power and scanning speed were applied. The physical and chemical properties of the produced surfaces were examined. SEM, EDX and XRD analyses were performed and were correlated to hardness results. Corrosion resistance of the treated surface was investigated to evaluate their performance in aggressive media and chemical and medical applications. From the obtained data it can be concluded that Nd-YAG laser surface melting of aluminum results in formation of 750 micron nano-structured surface layer. Adjustment of LSM parameters could produce 100 nm grains or less. The obtained results showed also that LSM under argon can eliminate the formation of Al2O3 surface layer which may deteriorates the performance in certain applications. Surface layer rich in AlN is formed upon LSM. It was concluded also that corrosion resistance of the treated aluminum surfaces was improved to large extent by LSM.

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.

scholarly journals Morphological and Functional Features of Parasitology Objects and Their Reflection in the Terminology

2020 ◽  
pp. 335-341
Author(s):  
E.V. Lapochkina ◽  
O.K. Stakovetskaya
Keyword(s):  
Educational Process ◽  
Semantic Association ◽  
Functional Characteristics ◽  
Ultimate Source ◽  
History Of ◽  
Functional Features

The article considers the morphological and functional characteristics of some objects of parasitology, the etymology of names and the methods of their nomination. Knowledge of the history of origin, the realization of the word-building analysis of parasite names and understanding the semantic components of terms will help to make the educational process more interesting and more effective. The names of parasites are divided into several groups: the names, in which there are semantic elements, which indicate the names of diseases; the names, comprising the semantic elements of anatomical nature; the names, comprising the semantic elements of geographical nature; the names, indicating the connection of term with the history of its detection and containing surnames of researchers; the names, containing semantic elements, which characterize the exterior view of parasites. Besides, the article shows the connection of semantic association (metaphorical transfer) between the initial meaning of the term in the language — ultimate source (Latin or Greek) with the morphological and functional characteristics of various parasites.

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