Influence of the initial roughness of the antifriction carbons surface on tribotechnical characteristics and running-in coating efficiency

2021 ◽  
pp. 158-169
Author(s):  
I. V. Lishevich ◽  
A. V. Anisimov ◽  
A. S. Savelov ◽  
A. S. Sargsyan ◽  
M. Yu. Sobolev
Keyword(s):  
Surface Roughness ◽  
Friction Surface ◽  
Sliding Friction ◽  
Friction Units ◽  
Carbon Plastics ◽  
Coating Efficiency ◽  
Optimal Surface ◽  
Mechanical Cutting ◽  
The Relationship ◽  
Tribotechnical Characteristics

The roughness of the friction surface of antifriction carbons used in sliding friction units lubricated with water affects the tribotechnical characteristics during the running-in process. This article experimentally substantiates the range of optimal surface roughness formed during mechanical cutting of carbon plastics in terms of tribotechnical efficiency. The results of a series of tribotechnical tests using various methods under various conditions (contact pressure, sliding speed, counterbody materials) are presented. The relationship between the initial roughness and the effectiveness of a running-in coating based on FORUM® polytetrafluoroethylene powder is established.

Tribotechnical characteristics of hard alloys in sliding friction units

2020 ◽  
pp. 87-97
Author(s):  
K. D. Khromushkin ◽  
B. G. Ushakov ◽  
A. V. Kochergin ◽  
R. A. Suleev ◽  
O. N. Parmenova
Keyword(s):  
Experimental Data ◽  
Sliding Friction ◽  
Heating Temperature ◽  
Hard Alloys ◽  
Friction Units ◽  
Wear And Friction ◽  
Friction Path ◽  
Friction Parameters ◽  
Tribotechnical Characteristics ◽  
Temperature Surface

The paper presents experimental data on the study of the friction parameters of hard alloys in sliding friction units, including the heating temperature, surface roughness, wear and friction coefficient, depending on the duration of the test and the friction path.

Influence of sliding bearing design on efficiency of the fluoroplast macromodifier for antifriction carbon plastics

2021 ◽  
pp. 65-75
Author(s):  
I. V. Lishevich ◽  
A. V. Anisimov ◽  
G. I. Nikolaev ◽  
A. S. Savelov ◽  
A. S. Sargsyan
Keyword(s):  
Sliding Friction ◽  
Friction Unit ◽  
Sliding Bearings ◽  
Friction Zone ◽  
Reinforced Plastics ◽  
Friction Units ◽  
Carbon Plastics ◽  
Key Factor ◽  
Fiber Reinforced Plastics ◽  
Bearing Design

The paper presents the results of laboratory and bench tests of UGET and FUT antifriction carbon plastics macro modified with PTFE. The efficiency (friction coefficient reduction) of this modification of carbon fiber reinforced plastics has been confirmed. The dependence of the method’s efficiency on the design of sliding friction units has been established. The plastic deformation of the fluoroplastic is the key factor that determines the effectiveness of the modifier when designing sliding bearings. The design of the friction unit should exclude the pressure gradient in the fluoroplastic protectors and prevent the possibility of an uncontrolled exit of the fluoroplastic from the friction zone.

Yarn and fabric properties in a modified ring spinning system considering the effect of the friction surface of the false-twister

2019 ◽  
Vol 90 (5-6) ◽  
pp. 572-580 ◽  
Author(s):  
Rong Yin ◽  
Xiao-Ming Tao ◽  
Bin-gang Xu
Keyword(s):  
Surface Roughness ◽  
Friction Surface ◽  
Experimental Results ◽  
Material Surface ◽  
Ring Spinning ◽  
Knitted Fabrics ◽  
Yarn Properties ◽  
Cotton Yarns ◽  
The Relationship

This paper experimentally studies the relationship between the friction surface of a false-twisting unit and the quality of cotton yarns produced by a modified ring spinning system, with the adoption of the single friction-belt false-twister. The friction surface of the false-twisting unit, as a key twisting component, has been studied in terms of material, surface roughness, hardness and diameter, as well as the interaction between these factors and resultant yarn properties, with particular attention to yarn imperfections. Experimental results showed that the false-twisting unit with a short interactive path demonstrated significant reduction of yarn imperfections, especially yarn neps. With the optimal false-twisting unit, performances of the modified yarns and their knitted fabrics were evaluated and compared with the conventional ones.

scholarly journals A Proposed Scan Strategy Used on SLM Inner Structure Part

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 937 ◽  
Author(s):  
Jitai Han ◽  
Meiping Wu ◽  
Weipeng Duan
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Laser Energy ◽  
Side Surface ◽  
Test Results ◽  
New Strategy ◽  
Optimal Surface ◽  
The Relationship ◽  
Main Factor

A model with an inner structure was designed to study the relationship between the surface quality of the inner structure and the scan strategy in this study. The test results showed that the precision of the inner structure was highly affected by the scan strategy, and the specimens printed using different strategies showed different performances on the surface quality of the inner structure. The specimen printed using the square-framed scan strategy had a lower flatness value on the positive face of the inner structure compared to that of the other two specimens printed using Z-shape scan strategies, while the specimen printed using the Z-shape scan strategy (along the inner structure) had a relative optimal surface roughness on the side surface of the inner structure in all three specimens. The bending deformation caused by the scan strategies was considered to be the main factor affecting the flatness on the positive surface, while laser energy fluctuation showed a significant impact on side surface roughness. Combined with the experimental data, a new scan strategy was proposed; we found that the specimen printed using this new strategy improved positive surface flatness and side surface roughness.

Numerical investigation of sliding friction behaviour and mechanism of engineering surfaces

2019 ◽  
Vol 71 (2) ◽  
pp. 205-211 ◽  
Author(s):  
Xiaogang Zhang ◽  
Yali Zhang
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Sliding Friction ◽  
Normal Load ◽  
Numerical Results ◽  
Operating Conditions ◽  
Friction Mechanism ◽  
Content Type ◽  
Optimal Surface ◽  
Friction Behaviour

Purpose This study aims to investigate the sliding friction behaviour and mechanism of engineering surfaces. Design/methodology/approach A new numerical approach is proposed. This approach derives the macroscale friction coefficient from microscale asperity interactions. By applying this approach, the sliding friction behaviour under different operating conditions were investigated in terms of molecular and mechanical components. Findings Numerical results demonstrate an independent relationship between normal load and friction coefficient, which is governed by the saturated plastic ratio. Numerical results also demonstrate that under very small load, an increase in load increases the friction coefficient. In addition, numerical results confirm the existence of optimal surface roughness where the friction coefficient is the lowest. For the surface profiles used in the current calculation, an optimal surface roughness value is obtained as Rq = 0.125 μm. Originality/value This new approach characterizes the deterministic relationship between macroscale friction coefficient and microscale asperity molecular/mechanical interactions. Numerical results facilitate the understanding of sliding friction mechanism.

Characteristics of TiO2 Nanotube Arrays on Titanium Prepared by Anodization

2011 ◽  
Vol 492 ◽  
pp. 291-295 ◽  
Author(s):  
Dan Li ◽  
Cheng Yun Ning ◽  
Guo Xin Tan ◽  
Hua De Zheng ◽  
Yong Mei Ge
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Flat Surface ◽  
Titanium Substrate ◽  
Nanotube Arrays ◽  
Oh Groups ◽  
X Ray ◽  
Atomic Force ◽  
Optimal Surface ◽  
The Relationship

Titania nanotube (NT) arrays with a length of 550nm were fabricated on the flat titanium substrate by anodization. The microstructure was identified by scanning electron microscope. The composition has been investigated with X-ray photoelectron microscopy. It also showed that, as compared with the flat surface, the density of Ti-OH groups on the NT surface has been increased. However, according to the contact angle goniometer, the hydrophilicity of the NT surface becomes worse than that of the flat surface. In addition, surface roughness was investigated by non-contact atomic force microscope. It demonstrated that the nano-roughness of NT arrays has been increased. More important is the relationship between contact angle and roughness factor have been analyzed based on the modified Young’s equation. These results indicate that the anodized NT structures may have provided an optimal surface roughness for promoting the bioactivity.

scholarly journals Aluminum Composite Materials Providing Extended Service Life

2021 ◽  
pp. 44-54
Author(s):  
Yulia A. Kurganova ◽  
Alexey G. Kolmakov ◽  
Sergey V. Kurganov
Keyword(s):  
Dry Friction ◽  
Sliding Friction ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composite ◽  
Aluminum Composite ◽  
Phase Mixing ◽  
Friction Units ◽  
Sic Particles ◽  
Tribotechnical Characteristics ◽  
Better Than

Hardness and tribotechnical characteristics were investigated under conditions of dry sliding friction on steel obtained by liquid-phase mixing of Aluminum-Matrix Composite (AMC) materials based on aluminum alloys AK12, D16, V124, AL9, AL25, reinforced with silicon carbide SiC particles with a size of 28 μm with a content of 5, 10 or 15% by volume. AMC performed better than matrix alloys and the commonly used antifriction aluminum alloy AOM 2-1. The dry friction coefficient was 1.5-3 times lower on average, and the volumetric wear rate was 5-9 times lower. An increase in the content of SiC particles in the composite from 5 to 20 vol.%. As a rule, leads to an improvement in the tribotechnical characteristics. The composites obtained have shown a sufficiently high operational suitability for work in friction units with steels both in dry friction and in friction with lubrication.

Influence of carbon fiber on tribotechnical characteristics of polyetheretherketone

2020 ◽  
Vol 98 (4) ◽  
pp. 27-32
Author(s):  
O. Buria ◽  
◽  
A.-M. Tomina ◽  
I. Nachovnyi ◽  
◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Transfer Film ◽  
Fiber Content ◽  
Polymer Fiber ◽  
Ultrasonic Control ◽  
Dispersed Particles ◽  
Friction Units ◽  
Carbon Plastics ◽  
Base Polymer ◽  
Tribotechnical Characteristics

Superstructural thermoplastic polymers, including polyetheretherketone, are now widely used in many industries. However, its rather high coefficient of friction and insufficient wear resistance limits its use in friction units of machines and mechanisms. This article covers the influence of T700 Toray carbon fiber on the tribotechnical characteristics of Victrex150G aromatic polyetheretherketone. As a result of the researches it has been found out that the developed carbon plastics exceed the base polymer in friction coefficient and wear 1.2-1.54 and 1.7-8.8 times, respectively, due to the formation of a stable "transfer film" on the steel counterbody (so-called antifriction layer): finely dispersed particles of the polymer matrix and crushed products of wear of carbon fiber penetrate into the microcavities of the counterbody. This is confirmed by the fact that the roughness of carbon plastics has decreased by 50 % in cpomparison with the base polymer. The greatest improvement in tribological properties is observed at 10 mass%, of carbon fiber content, then the properties get worse. That can be explained by the increase in defects of the material due to the dominant loosening at the "polymer-fiber" boundary that confirms the results of microhardness and ultrasonic control. The obtained results show that the composite with an effective carbon fiber content (10 mass%) can be recommended for the manufacture of parts of movable joints of machines and mechanisms operating under friction without lubrication in various industries: agricultural, automotive and textile. etc.

Possible examinations of stone machining focused on the relationship between technological parameters and surface quality

2013 ◽  
Vol 4 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Zs. Kun ◽  
I. G. Gyurika
Keyword(s):  
Surface Roughness ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Theoretical Background ◽  
Motion Path ◽  
Depth Of Cut ◽  
Manufacturing Cost ◽  
Technological Parameters ◽  
The Relationship ◽  
Manufacturing Time

Abstract The stone products with different sizes, geometries and materials — like machine tool's bench, measuring machine's board or sculptures, floor tiles — can be produced automatically while the manufacturing engineer uses objective function similar to metal cutting. This function can minimise the manufacturing time or the manufacturing cost, in other cases it can maximise of the tool's life. To use several functions, manufacturing engineers need an overall theoretical background knowledge, which can give useful information about the choosing of technological parameters (e.g. feed rate, depth of cut, or cutting speed), the choosing of applicable tools or especially the choosing of the optimum motion path. A similarly important customer's requirement is the appropriate surface roughness of the machined (cut, sawn or milled) stone product. This paper's first part is about a five-month-long literature review, which summarizes in short the studies (researches and results) considered the most important by the authors. These works are about the investigation of the surface roughness of stone products in stone machining. In the second part of this paper the authors try to determine research possibilities and trends, which can help to specify the relation between the surface roughness and technological parameters. Most of the suggestions of this paper are about stone milling, which is the least investigated machining method in the world.

Contact Analysis of Tire Tread Rubber on Flat Surface with Microscopic Roughness3

2006 ◽  
Vol 34 (4) ◽  
pp. 237-255 ◽  
Author(s):  
M. Kuwajima ◽  
M. Koishi ◽  
J. Sugimura
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Sliding Friction ◽  
Tangential Force ◽  
Partial Slip ◽  
Real Contact Area ◽  
Element Analysis ◽  
Real Contact ◽  
Local Slip ◽  
Tread Rubber

Abstract This paper describes experimental and analytical studies of the dependence of tire friction on the surface roughness of pavement. Abrasive papers were adopted as representative of the microscopic surface roughness of pavement surfaces. The rolling∕sliding friction of tire tread rubber against these abrasive papers were measured at low slip velocities. Experimental results indicated that rolling∕sliding frictional characteristics depended on the surface roughness. In order to examine the interfacial phenomena between rubber and the abrasive papers, real contact length, partial slip, and apparent friction coefficient under vertical load and tangential force were analyzed with two-dimensional explicit finite element analysis in which slip-velocity-dependent frictional coefficients were considered. Finite element method results indicated that the sum of real contact area and local partial slip were larger for finer surfaces under the same normal and tangential forces. In addition, the velocity-dependent friction enhanced local slip, where the dependence of local slip on surface roughness was pronounced. It proved that rolling∕sliding friction at low slip ratio was affected by local frictional behavior at microslip regions at asperity contacts.

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