Friction Coefficient Variation Mechanism under Wet Condition in Disk Brake (Variation Mechanism Contributing Wet Wear Debris)

2016 ◽  
Vol 9 (3) ◽  
pp. 1227-1234 ◽  
Author(s):  
Tadayoshi Matsumori ◽  
Yoshitsugu Goto ◽  
Noboru Sugiura ◽  
Kenji Abe ◽  
Yoshihiro Osawa ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Debris ◽  
Coefficient Variation ◽  
Disk Brake ◽  
Wet Condition ◽  
Variation Mechanism

scholarly journals Articular Cartilage Wear Characterization With a Particle Sizing and Counting Analyzer

2012 ◽  
Author(s):  
Sevan R. Oungoulian ◽  
Orian Bortz ◽  
Kristin E. Hehir ◽  
Kaicen Zhu ◽  
Clark T. Hung ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Friction Coefficient ◽  
Wear Debris ◽  
Polyethylene Wear ◽  
Quantitative Measurements ◽  
Diarthrodial Joints ◽  
Cartilage Wear ◽  
Tangential Forces ◽  
Fluid Pressurization

The primary function of articular cartilage is to serve as the bearing material in diarthrodial joints, transmitting loads while minimizing friction and wear. The friction coefficient of cartilage has been characterized extensively in the literature, using standard measurements of normal and tangential forces acting across a sliding interface [1]. However, quantitative measurements of cartilage wear have proven to be more challenging, with only a few studies having reported such measurements. The primary quantitative approaches proposed to date include biochemical assaying of cartilage and test solutions [2], and characterization of changing articular layer thickness [3] and surface roughness [4]. One study examining polyethylene wear debris in hip arthroplasty reported the use of an automated particle analyzer [5]. The aim of this study was to test the hypothesis that latest-generation particle analyzers are capable of detecting cartilage wear debris generated during in vitro loading experiments that last 24 h or less, by producing measurable content significantly above background noise levels. The longer-term objective of our studies is to test the hypothesis that elevated interstitial fluid pressurization, which is known to reduce the friction coefficient of cartilage [6], also reduces cartilage wear.

Properties of Jute Fibers Reinforced Friction Materials

2011 ◽  
Vol 399-401 ◽  
pp. 474-477
Author(s):  
Yun Hai Ma ◽  
Su Qiu Jia ◽  
Bao Gang Wang ◽  
Wei Ye ◽  
Jin Tong ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Friction Coefficient ◽  
Wear Debris ◽  
Temperature Decrease ◽  
Heating Condition ◽  
Friction Materials ◽  
Abrasive Particles ◽  
Jute Fibers ◽  
The Matrix ◽  
Worn Surface

Jute fibers reinforced friction materials were prepared by mold and heat treatment. The friction coefficients of 3wt.%,9wt.% and 12wt.% jute fibers reinforced friction materials were bigger than that of the materials without jute fibers in the heating condition. The friction coefficient of 6 wt.% jute fibers reinforced friction materials was bigger than that of the materials without jute fibers below 250°C. The friction coefficient of jute fibers reinforced friction materials deceased with the temperature decrease in the cooling condition. The friction coefficient of the materials with free-jute fibers raised from 350-250°C and reduced at the temperature lower than 250°C.Wear rates of the friction materials raised with temperature rise for jute fibers carbonization led to the matrix became loose. With jute fibers content rise worn surface of the reinforced materials became from smooth to rough. There were pits, grooves, abrasive particles, pulled out fibers and wear debris on the worn surfaces. Abrasive wear was the main wear mechanism.

Study on the Friction and Wear Behavior of Grind-Hardened Layer

2010 ◽  
Vol 431-432 ◽  
pp. 385-388 ◽  
Author(s):  
Jian Hua Zhang ◽  
Pei Qi Ge ◽  
Lei Zhang ◽  
Yang Yu ◽  
Hui Li
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Wear Debris ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Hardened Layer ◽  
Hardened Steel ◽  
Wear Performance ◽  
Friction And Wear Behavior ◽  
Grind Hardening

The grind-hardening technology utilizes the grinding heat to harden the surface of the workpiece. The friction and wear performance of the grind-hardened layer is one of the important parameters. In this paper, the friction and wear performance of the grind-hardened layer was studied by the friction and wear experiment. The wear rate and the friction coefficient of the grind-hardened steel were studied by comparing with conventional hardened steel and non-hardened steel. The surface worn morphology and the collected wear debris of the grind-hardened steel were observed during the experiment. The wear mechanism of the grind-hardened steel was analyzed under different friction conditions.

ADHESIVE WEAR PERFORMANCE OF CFRP MULTILAYERED POLYESTER COMPOSITES UNDER DRY/WET CONTACT CONDITIONS

2008 ◽  
Vol 15 (06) ◽  
pp. 919-925 ◽  
Author(s):  
D. DANAELAN ◽  
B. F. YOUSIF
Keyword(s):  
Friction Coefficient ◽  
Adhesive Wear ◽  
Optical Microscope ◽  
Contact Condition ◽  
Wear Performance ◽  
Dry Contact ◽  
Wet Condition ◽  
Wear Mode ◽  
Wet Contact ◽  
Coconut Fibers

The tribo-performance of a new engineering composite material based on coconut fibers was investigated. In this work, coconut fibers reinforced polyester (CFRP) composites were developed. The tribo-experiments were conducted by using pin-on-disc machine under dry and wet sliding contact condition against smooth stainless steel counterface. Worn surfaces were observed using optical microscope. Friction coefficient and specific wear rate were presented as a function of sliding distance (0–0.6 km) at different sliding velocities (0.1–0.28 m/s). The effect of applied load and sliding velocity was evaluated. The results showed that all test parameters have significant influence on friction and wear characteristics of the composites. Moreover, friction coefficient increased as the normal load and speed increased, the values were about 0.7–0.9 under dry contact condition. Meanwhile, under wet contact condition, there was a great reduction in the friction coefficient, i.e. the values were about 0.1–0.2. Furthermore, the specific wear rates were found to be around 2–4 (10-3) mm3/Nm under dry contact condition and highly reduced under wet condition. In other words, the presence of water as cleaner and polisher assisted to enhance the adhesive wear performance of CFRP by about 10%. The images from optical microscope showed evidence of adhesive wear mode with transition to abrasive wear mode at higher sliding velocities due to third body abrasion. On the other hand, optical images for wet condition showed less adhesive wear and smooth surfaces.

scholarly journals Abrasive Wear Resistance of Plasma-Nitrided Ti Enhanced by Ultrasonic Surface Rolling Processing Pre-Treatment

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3260
Author(s):  
Dingshun She ◽  
Shihao Liu ◽  
Jiajie Kang ◽  
Wen Yue ◽  
Lina Zhu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Abrasive Wear ◽  
Wear Debris ◽  
Plasma Nitriding ◽  
Lunar Regolith ◽  
Nitride Layer ◽  
Abrasive Wear Resistance ◽  
Pre Treatment ◽  
Worn Surface

The objective of the given work was to investigate abrasive wear behaviours of titanium (Ti) treated by ultrasonic surface rolling processing (USRP) pre-treatment and plasma nitriding (PN). Simulated lunar regolith particles (SLRPs) were employed as abrasive materials during characterization of tribological performances. The experimental results showed that SLRPs cause severe abrasive wear on Ti plasma-nitrided at 750 °C via the mechanism of micro-cutting. Due to the formation of a harder and thicker nitriding layer, the abrasive wear resistance of the Ti plasma-nitrided at 850 °C was enhanced, and its wear mechanism was mainly fatigue. USRP pre-treatment was effective at enhancing the abrasive wear resistance of plasma-nitrided Ti, due to the enhancement of the hardness and thickness of the nitride layer. Nevertheless, SLRPs significantly decreased the friction coefficient of Ti treated by USRP pre-treatment and PN, because the rolling of small granular abrasives impeded the adhesion of the worn surface. Furthermore, USRP pre-treatment also caused the formation of a dimpled surface with a large number of micropores which can hold wear debris during tribo-tests, and finally, polishing and rolling the wear debris resulted in a low friction coefficient (about 0.5).

The study of friction layer and tribological property of PI–matrix composites

2017 ◽  
Vol 69 (2) ◽  
pp. 267-275 ◽  
Author(s):  
Xiulin Xu ◽  
Xing Lu ◽  
Zuoxiang Qin ◽  
Dalong Yang
Keyword(s):  
Friction Coefficient ◽  
Tribological Property ◽  
Wear Debris ◽  
Friction Pair ◽  
Matrix Composites ◽  
Low Friction ◽  
Friction Layer ◽  
Content Type ◽  
Compact Zone ◽  
Pin On Disk

Purpose This paper aims to study the friction layer and tribological property of polyimide (PI)–matrix composites under different friction speeds. Design/methodology/approach Friction tests were conducted under friction speeds ranging from 20-120 km/h and pressure of 0.57 MPa by a pin-on-disk tribometer. Findings The results indicate that the friction coefficient decreases with the increasing of the friction speed. Under different friction speeds, the structure of the friction layer and debris are different, which affects the actual tribological performance of the composites. At low friction speed, the morphology of the friction layer is mainly particulate. The higher level of clenching action between the friction pair leads to a high friction coefficient, and the morphology of the particles in the particulate zone and the wear debris are mostly equiaxial particles. At high friction speed, the morphology of the friction layer is mainly a compact zone. The reduction of the surface roughness leads to a low friction coefficient. The debris collected on the counter surface at high friction speeds are mostly big sheets, and the morphology of the particles in the particulate zone is mostly rod-like. Controlling the conditions of the disk and the pin can reveal the influence of friction speed on the friction layer. The wear mechanisms at different friction speeds are also discussed. Originality/value By controlling the conditions of the disk and the pin to reveal the influence of friction speed on the friction layer, and the evolutions of the friction layer, wear debris were carefully inspected with the aim of demonstrating the relationship between friction speed and wear mechanism of PI–matrix composites.

A Study and Development of Frictional Materials Containing Fly Ash for Motorcycle Clutch Production

2013 ◽  
Vol 811 ◽  
pp. 120-125
Author(s):  
Phongphat Laothanasakul ◽  
Karuna Tujinda ◽  
Sirinthorn Thongsang
Keyword(s):  
Fly Ash ◽  
Friction Coefficient ◽  
Wear Debris ◽  
Raw Materials ◽  
Chemical Properties ◽  
Minimum Cost ◽  
Static Friction ◽  
Wear Rates ◽  
Original Product ◽  
Frictional Materials

In this work, the properties of frictional materials for motorcycle clutch with fly ash replacements of some original substances were studied aiming to reduce the raw materials cost. The fly ash was obtained from the domestic BLCP power plant in Rayong, Thailand. Two replacement schemes were studied;1) all of the original ingredients comprising the clutch was replaced with 15-35 %wt. fly ash and 2) only the original ingredients with similar physical and chemical properties were replaced with 40-55 %wt. fly ash. The mechanical properties, the friction coefficient and the wear performance were then studied. In addition, micro-structural characterizations of the contact surface and the wear debris were carried out. It was found that the fly ash replacement to a certain level increased the hardness resulting in a decrease in the surface wear. The specimens with fly ash replacement were found to have smoother surface leading to a lower static friction coefficient. The dynamic friction coefficient was altered according to the wear debris characteristics. The prototypes with the optimum amount of fly ash, i.e. giving minimum cost with superior or similar properties to the original product, for each scheme was produced and tested on a dynamometer. The prototypes for the 1st and 2nd schemes were found to offer the reduction in the wear rates of approx. 22 to 56% with a reduction in the cost of raw materials of approx. 15 and 23%, respectively. Severe damage of the prototypes was observed slightly sooner than that found for the original product.

Chromium Addition Effect on Wear Properties of Cast-Iron Material

2015 ◽  
Vol 809-810 ◽  
pp. 572-577
Author(s):  
Costel Florea ◽  
Costică Bejinariu ◽  
Viorel Paleu ◽  
Daniela Chicet ◽  
Ioan Carcea ◽  
...  
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Point Of View ◽  
Material Surface ◽  
Wear Properties ◽  
Experimental Conditions ◽  
Disk Brake ◽  
Friction Regime ◽  
New Material ◽  
Iron Material

A new cast iron material with a higher Cr content than usual is analyzed by chemical, micro-structural and friction coefficient point of view. The material was obtained by classical melting and the results compared with the experimental results obtained from a standard cast-iron used for applicative disk brake. Four different mechanical solicitation rates were used on the same material surface and the same load. The solicitation regime can be considered as semi-liquid and similar to a raining day experimental conditions. In this paper no thermal considerations were present or discussed. The results present a bigger friction coefficient of the new material and further considerations are necessary for example in a different friction regime.

Study on Tribological Performance of Fine-Grained Diamond Films

2007 ◽  
Vol 359-360 ◽  
pp. 23-27
Author(s):  
Bin Shen ◽  
Wei Zuo ◽  
Fang Hong Sun ◽  
Ming Chen
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Wear Debris ◽  
Wear Behavior ◽  
Water Environment ◽  
Ambient Air ◽  
Bearing Steel ◽  
Specific Wear Rate ◽  
Fine Grained ◽  
Diamond Grain

Friction and wear behavior of fine-grained diamond (FGD) films were investigated in the ambient air, deionized water and paraffin oil lubricating environment. The FGD films were deposited on WC substrates using HFCVD method and the tribologcial tests were conducted in a ball-on-plate type reciprocating friction tester where the mating balls were made of ball-bearing steel. Scanning electron microscopy (SEM), surface profilometer and Raman spectrascropy were used to study the characterizations of the deposited FGD films, and after sliding tests, the worn areas on both mating balls and FGD films were investigated and the wear debris layer adhered to the friction area of FGD films were analyzed with EDX. The experiment results suggested that FGD films exhibited steady friction coefficient as about 0.25 in water, lower than that in open air, which is up to 0.40; but the mating ball in water suffered much severer wear lost and its specific wear rate was more than two times higher than that in air, up to 3.6E-4 mm3N-1m-1. As while, a thick and compact layer of wear debris was observed on the worn area of FGD films sliding with water lubrication while only little debris existed in the diamond grain boundaries, which might dominate the friction process and attribute to the lower friction coefficient and higher specific wear rate in water environment. In oil environment, furthermore, both the friction coefficient and specific wear rate reached minimum value as low as 0.1 and 1.1E-4 mm3N-1m-1, no observable wear scar could be measured on the sliding surface of the FGD film.

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