scholarly journals Effect of Polypropylene Modification by Impregnation with Oil on Its Wear and Friction Coefficient at Variable Load and Various Friction Rates

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Paweł Sędłak ◽  
Beata Białobrzeska ◽  
Tomasz Stawicki ◽  
Piotr Kostencki
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Wear Test ◽  
Friction Torque ◽  
Engine Oil ◽  
Wear Testing ◽  
Wear Behaviour ◽  
Linear Wear ◽  
Variable Load ◽  
Fatigue Wear

Laboratorial two-body wear testing was carried out in order to assess effects of polypropylene modification by impregnating it with oils on friction coefficient and wear in comparison to those parameters of unmodified polypropylene, Teflon, and polyamide during operation under conditions of sliding friction without lubrication. Wear behaviour of the tested specimens was investigated using ASTM G77-98 standard wear test equipment. Recording program made it possible to visualise and record the following parameters: rotational speed and load, linear wear, friction coefficient, temperature of the specimen, and ambient temperature. In addition, wear mechanisms of the analysed materials were determined with use of scanning electron microscopy. In the case of the remaining tested polymers, the most important mechanism of wear was adhesion (PP, PTFE, PA 6.6, and PA MoS2), microcutting (PTFE, PA 6.6, and PA MoS2), fatigue wear (PTFE), forming “roll-shaped particles” combined with plastic deformation (PA 6.6 and PA MoS2), and thermal wear (PP). Impregnation of polypropylene with engine oil, gear oil, or RME results in significant reduction of friction coefficient and thus of friction torque, in relation to not only unmodified polypropylene but also the examined polyamide and Teflon.

Effect of Graphite Content on Cu–Ni–Graphite Composite for Use as Switch Slide Baseplate Materials Sliding Against U75V Steel

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Yiran Wang ◽  
Yimin Gao ◽  
Jun Takahashi ◽  
Yi Wan ◽  
Yunqian Zhang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Mechanism ◽  
High Speed ◽  
Sliding Friction ◽  
Rapid Development ◽  
Wear Volume ◽  
Fatigue Wear ◽  
Friction Coefficients ◽  
Graphite Composite ◽  
Graphite Content

Abstract The rapid development of high-speed railways necessitates the development of new materials for switch slide baseplates. In this study, a Cu–Ni–graphite composite, containing 1 wt% to 6 wt% graphite and prepared by powder metallurgy, was used as a potential material. Pin-on-disk wear tests were conducted to measure the sliding friction of the Cu–Ni–graphite composite against U75 V steel. The results showed that the friction coefficients gradually decreased when the graphite content in the composite ranged from 1 wt% to 4 wt% in the composite. When the graphite content was 4 wt%, the friction coefficient reached the minimum value (0.153). When the graphite content was low (1 wt% to 4 wt%), the primary wear mechanism was microcutting. An increased graphite content facilitated the generation of lubricating films and decreased the wear damage. As the graphite content increased from 4 wt% to 6 wt%, the friction coefficients also increased. The variation in the wear volume rate had the same tendency as the friction coefficient. When the graphite content exceeded 4 wt%, the primary wear mechanism was delamination and fatigue wear. Due to the tendency to form cracks on the subsurface and the plentiful generation of the spalled pits, the graphite fragments could not completely form lubricating films but separated as wear debris. The lubricating films existing on the U75 V steel were in proportion to the graphite content in the composite. The wear weight loss of the U75 V steel exhibited a reduction with increasing graphite content.

The Research on the Lubricating Property of Oil-Air Lubrication in the Sliding Friction Element

2013 ◽  
Vol 572 ◽  
pp. 397-400
Author(s):  
Shao Gang Liu ◽  
Li Quan Li ◽  
Jin Li Wang
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Testing Machine ◽  
Wear Testing ◽  
Conical Nozzle ◽  
Rotating Speed ◽  
Friction Element ◽  
Oil Supply ◽  
Air Supply ◽  
Air Lubrication

The influence of the oil supply, nozzle type, air supply, the performance of sliding friction element under the lubrication preloads were investigated by measuring the element’s temperature and friction coefficient based on the M2000-A friction wear testing machine. When the load, rotating speed and air supply is at 1500N, 210rpm and 2.25 m3/h level respectively, as the oil supply is increased, the temperature rises and friction coefficient decreases. The temperature rise decreases monotonically. The friction coefficient rises monotonically with the air supply increases when the air supply is less than 2.4m3/h, but when the air supply is more than 2.4m3/h, the friction coefficient decreases monotonically. Furthermore, when the oil supply is reached 15ml/h, they remain almost unchanged regardless of direct nozzle and conical nozzle. Nevertheless, the direct nozzle is more suitable than the conical nozzle in oil-air lubrication of the sliding friction pairs .

Wear of Spiral Seal Cone Bit in Complex Formations

SPE Journal ◽  
2021 ◽  
pp. 1-16
Author(s):  
Y. Zhou ◽  
J. H. Hu ◽  
B. Tan ◽  
Y. Jiang ◽  
Y. F. Tang
Keyword(s):  
Friction Coefficient ◽  
Working Conditions ◽  
Wear Mechanism ◽  
Testing Machine ◽  
Wear Test ◽  
Simulation Method ◽  
Wear Testing ◽  
Wear Loss ◽  
Wear Depth ◽  
Wear Properties

Summary Sealing is a technical bottleneck that affects drilling efficiency and cost in deep, difficult-to-drill formations. The spiral combination seal with active sand removal performance is a new type of seal, and the wear mechanism is not clear, resulting in no effective design. In this study, the wear properties of materials were measured by a friction-and-wear testing machine, and the measurement methods and criteria of wear loss and friction coefficient were established. The fitting function of working condition and friction coefficient was studied by fitting regression method. The law of influence of working conditions on friction coefficient and wear amount was determined. The actual wear model and evaluation criteria of wear condition were established by using wear test data and geometric relationship. The relationship among working conditions, contact stress, and wear depth is determined by numerical simulation method, and the wear mechanism of the new seal is revealed, which provides a theoretical basis for its application.

Research on wear resistance of plasma remelted FeNiCrAl sprayed coating

2016 ◽  
Vol 232 (12) ◽  
pp. 1036-1043 ◽  
Author(s):  
Zhongqi Sheng ◽  
Jing Zhou ◽  
Jiayao Xuan ◽  
Shicheng Wei ◽  
Yujiang Wang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Sliding Friction ◽  
Testing Machine ◽  
Wear Test ◽  
Wear Testing ◽  
Arc Spraying ◽  
Microhardness Distribution ◽  
Metallurgical Bonding ◽  
Microstructure Density ◽  
Sprayed Coating

To improve the microstructure density of high-velocity arc spraying coating and enhance its adhesive strength and wear resistance, a plasma remelting investigation of the FeNiCrAl sprayed coating was carried out in this study. The microstructure and phase composition of the sprayed coating and the remelted coating were compared by using metalloscope, scanning electron microscope and X-ray diffractometer. The microhardness distribution and friction wear characteristics of the plasma remelted FeNiCrAl sprayed coating were investigated by microhardness tester and CETR sliding friction wear testing machine. The results showed that the remelted coating has more compact microstructure and presents metallurgical bonding with the substrate. The generation of hard phases such as (Fe,Cr)7C3 and Cr23C6 as well as solid solution (Fe,Cr) increases the microhardness of the remelted coating significantly, about 1.4 times higher than that of the sprayed coating. According to sliding friction wear test, the abrasion losses of the sprayed coating under 10 N and 20 N loads are 4.6 and 10.5 times higher than those of the remelted coating, indicating the better wear resistance of the remelted coating.

Investigation of carbon–carbon composite brake pads in wet and dry sliding wear conditions

2014 ◽  
Vol 66 (6) ◽  
pp. 645-652 ◽  
Author(s):  
Ugur Ozsarac ◽  
Salim Aslanlar ◽  
Faruk Varol ◽  
Mehmet Ekici
Keyword(s):  
Sliding Friction ◽  
Wear Test ◽  
Absorption Capacity ◽  
Rain Water ◽  
Wear Testing ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Content Type ◽  
Brake Pads ◽  
Pin On Disc

Purpose – The purpose of this study was to investigate wear behaviours of brake pads produced from carbon–carbon (C/C) composites in both wet and dry friction sliding conditions. Carbon is probably the most remarkable element in science and also C/C composites are a family of advanced composite materials. They are the most advanced form of carbon and consist of fibre based on carbon precursors embedded in a carbon matrix. In the present work, wear test specimens were prepared according to the related standards and they were exposed to pin-on-disc wear testing in wet and dry sliding conditions with different loads as 10, 20, 30 and 40 N with 1 m/s constant sliding speed. Wet friction process was conducted on all specimens by means of rain water collected from the nature. Design/methodology/approach – Pin-on-disc wear test tribology lubrication was used. Findings – Mechanical and physical property measurements of C/C composite brake pad materials: hardness, modulus of elasticity, density and water absorption capacity. Wear performance of materials were measured as coefficient of friction, volumetric loss and specific wear rate. Originality/value – C/C composite brake pads are used in railway vehicles. Wear performances of them are very important for safety. In this study, wear behaviours of these materials were investigated not only in dry sliding friction condition but also in wet sliding one. Because safety braking is important in all weather conditions for trains, and we used natural rain water to observe the wet sliding friction behaviour of brake pads. “Water lubrication” is an important aspect mentioned in tribology handbooks.

Research on Friction Property of Pin on Disc and Analysis of Wear Mechanism Based on MMW-1A Friction and Wear Testing Machine

2018 ◽  
Vol 764 ◽  
pp. 86-92
Author(s):  
Zhi Peng Chen ◽  
Xiao Yi Jin ◽  
Chun Yun Ji ◽  
Chuan Wang ◽  
Jian Liu Zhu
Keyword(s):  
Friction Factor ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Mechanical Design ◽  
Testing Machine ◽  
Wear Test ◽  
Wear Testing ◽  
Wear Volume ◽  
Test Machine ◽  
Pin On Disc

Friction and wear are very important in mechanical design. This paper studies the friction and wear characteristics of 45 steel under oil lubrication. The sliding friction and wear experiment was carried out with the pin plate friction pairs on the MMW-1A friction and wear test machine. Researching the influence of velocity on friction factor under the same load, the relation between wear and load and wear analysis under the same speed different loads. The results showed that under the same load and with the increase of velocity, the friction factor had a gradually decreasing trend. When some of the parameters were certain, the wear volume and the loading force was roughly linear relation. Pitting occurred when the load increased.

scholarly journals EVALUATION OF TRIBOLOGICAL CHARACTERISTICS OF MATERIAL PREPARED BY DMLS TECHNOLOGY

2021 ◽  
Vol 2021 (4) ◽  
pp. 4941-4945
Author(s):  
VLADIMIR SIMKULET ◽  
◽  
DARINA DUPLAKOVA ◽  
ALEXANDRA KOVALCIKOVA ◽  
MICHAL HATALA ◽  
...  
Keyword(s):  
Sliding Friction ◽  
Normal Load ◽  
Steel Powder ◽  
Wear Testing ◽  
Tribological Characteristics ◽  
Wear Behaviour ◽  
Dry Sliding ◽  
Prepared Material ◽  
Worn Surface ◽  
Ball On Disc

The method of producing molten metal powder according to the European laser sintering system (EOSINT) was used to prepare the experimental material. The used powder metal material was designated EOS Maraging Steel - MS1. It is a steel powder, which is optimized especially for processing in EOSINT M 280 systems. The measurement of tribological characteristics of prepared materials was performed using the standard STN ISO 20808: 2004. The ball-on-disc dry sliding friction and wear experiments have been made on prepared materials in contact with steel ball. For the experiment, there were determined the following conditions: the value of normal load 5 N, the sliding radius 2 mm. Wear testing was carried out at room temperature 25°C using the ball-on-disc technique. Wear behaviour of the prepared material was studied in dry sliding; relative humidity was 26-28%. The normal load of 5 N; and sliding speed of 0.1 m/s was applied. The total sliding distance was 1000 m. The worn surface was analysed by confocal microscope and scanning electron microscope.

Influence of Reinforcement of TiC Particles on Wear Behaviour of Al7075/TiC Composite Material

2020 ◽  
Vol 37 ◽  
pp. 37-45
Author(s):  
Eshan S. Agrawal ◽  
Vinod B. Tungikar
Keyword(s):  
Composite Material ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Centrifugal Casting ◽  
Testing Machine ◽  
Casting Machine ◽  
Wear Test ◽  
Wear Testing ◽  
Wear Behaviour ◽  
Weight Percentage

TiC particles are reinforced with Al 7075 to develop metal matrix composite. Special purpose die is fabricated for centrifugal casting machine for the preparation of composite material. The tribological properties such as wear rate and coefficient of friction are determined by using pin on disc wear testing machine. Weight percentage of TiC, applied load, sliding distance are considered as parameters for the wear test. The results show that the wear resistance of the developed composite increases with increase of TiC percentage. Wear rate of Al-TiC composite is observed to be reduced by 11%, 31% and 42% with increasing percentage of TiC by 2.5%, 5% and 7.5% respectively. SEM and EDS analysis are used for morphological study of the worn surfaces of composite. Keywords: Composites, Al-TiC, Wear, Coefficient of Friction (CoF), SEM

Sliding Friction and Wear Behavior of GCr15 Bearing Steel at Different Temperatures

2021 ◽  
Vol 324 ◽  
pp. 35-42
Author(s):  
Dong Yue Wang ◽  
Rong Chang Xu ◽  
Dian Xiu Xia ◽  
Shou Ren Wang ◽  
Ying Chao Pei ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Room Temperature ◽  
Sliding Friction ◽  
Wear Behavior ◽  
Testing Machine ◽  
Bearing Steel ◽  
Wear Testing ◽  
Fatigue Wear ◽  
Gcr15 Bearing Steel ◽  
Electron Image

The effects of temperature on the friction and wear properties of GCr15 were studied by using a RETC multifunctional friction and wear testing machine. The microstructure characterization of the worn surface of the experimental steel was studied by means of metallographic microscope (OM), white light interferometer, secondary electron image (SEI) and back scattered electron image (BEI).The results show that the wear resistance of GCr15 bearing steel at room temperature is better than that at 100°C, 150°C and 200°C. At room temperature, the main wear forms of GCr15 are adhesion wear and fatigue wear. However, at 100°C, 150°C, 200°C, the friction coefficient and oxidation degree in the wear zone first increase and then decrease with the increase of temperature, and the wear form is mainly oxidized wear, accompanied by abrasive wear.

The Quantification of Physiologically Relevant Cross-Shear Wear Phenomena on Orthopaedic Bearing Materials Using the MAX-Shear Wear Testing System

2005 ◽  
Vol 127 (4) ◽  
pp. 740-749 ◽  
Author(s):  
Matthew R. Gevaert ◽  
Martine LaBerge ◽  
Jennifer M. Gordon ◽  
John D. DesJardins
Keyword(s):  
Wear Test ◽  
Quantitative Relationship ◽  
Surface Damage ◽  
Sem Analysis ◽  
Wear Testing ◽  
Testing System ◽  
Linear Wear ◽  
Shear Surface ◽  
Wear Damage

Background: The occurrence of multi-directional sliding motion between total knee replacement bearing surfaces is theorized to be a primary wear and failure mechanism of ultra-high molecular weight poly(ethylene) (UHMWPE). To better quantify the tribologic mechanisms of this cross-shear wear, the MAX-Shear wear-testing system was developed to evaluate candidate biomaterials under controlled conditions of cross-shear wear. Method of approach: A computer controlled traveling x-y stage under a 3 degree-of-freedom statically loaded pin is used to implement the complex multi-directional motion pathways observed during TKR wear simulation. A MHz collection of dynamic x-y friction was available on all six environmentally controlled stations. The functionality of this testing platform was proven in a 100,000 cycle, 11.6 MPa, wear test using 15.0 mm diameter polished stainless steel spheres against flat GUR4150 UHMWPE. A five-pointed star wear pattern was used to incorporate the physiologically relevant cross-shear sliding conditions of stop/start, 50mm∕s entraining velocity and five crossing angles of 72°. Using normalized volumetric reconstruction of the resulting surface damage, a direct quantitative relationship between linear and cross-shear surface damage intensity was obtained. Results: Cross-shear surface damage volume loss was found to be 2.94 (±0.88) times that associated with linear sliding under identical tribologic conditions. SEM analysis of linear wear damage showed consistent fibril orientation along the direction of sliding while cross-shear wear damage showed multi-directional fibril orientations and increased surface roughness. Significant increases in discrete crossing-point friction coefficients were recorded throughout testing. Conclusions: This scientific approach to quantifying the tribologic effects of cross-shear provides fundamental wear mechanism data that are critical in evaluating potential biomaterials for use as in vivo bearings. Relevant multi-axis, cross-shear wear testing is necessary to provide quantifiable measures of complex biomaterials wear phenomena.

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