Dry Sliding Wear Studies of Copper-Based Powder Metallurgy Brake Materials

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Glenn Kwabena Gyimah ◽  
Ping Huang ◽  
Dong Chen
Keyword(s):  
Sintering Temperature ◽  
Wear Behavior ◽  
Friction Material ◽  
Dry Sliding Wear ◽  
Temperature Sensitive ◽  
The Novel ◽  
Different Temperatures ◽  
The Coefficient Of Friction ◽  
Novel Material ◽  
Mechanical And Tribological Characteristics

The paper focuses on a novel friction material on Cu-based powder metal material. Several elements, such as Al, SiO2, Fe, graphite, Sn, Mn, and MoS2 were added to the Cu and were developed by PM techniques. The aim of the experiment was to study the effect of increasing Sintering temperature on mechanical and tribological characteristics of the novel train brake pads. The materials prepared were sintered at three different temperatures (850 °C, 900 °C, and 950 °C). A high pressure pad-on-disk braking tester was developed to test the wear behavior of these materials without lubrication. Wear was measured by microscopic examination of the pad after the tribometer test. The tests showed that the coefficient of friction, wear rate and wear number were improved immensely by high temperature sintering. This means that, the level of the sintering temperature has significant effect on the performance of the braking material. Thereby, the tribological and the mechanical properties of the novel material were found to be temperature sensitive.

Dry Sliding Wear Studies of Cu-Based Powder Metallurgy Brake Materials

2012 ◽  
Author(s):  
Glenn K. Gyimah ◽  
Dong Chen ◽  
Ping Huang
Keyword(s):  
Sliding Wear ◽  
Wear Behavior ◽  
Friction Material ◽  
Dry Sliding Wear ◽  
Temperature Sensitive ◽  
Brake Pads ◽  
Different Temperatures ◽  
The Coefficient Of Friction ◽  
Materials Used ◽  
Mechanical And Tribological Characteristics

A novel friction material based on Cu-based powder with several additional elements, such as Al, SiO2, Fe, graphite, Sn, Mn and MoS2, has been developed by PM techniques in order to study the wear to improve mechanical and tribological characteristics of train brake pads. The materials used were sintered at three different temperatures (850°C, 900°C and 950°C). A high pressure pad-on-disc braking tester was developed to test the wear behavior of these materials without lubrication. Wear was measured by microscopic examination of the pad after the tribometer test. The tests showed that the coefficient of friction (COF), wear rate and wear number were improved immensely by high temperature sintering. This shows that the sintering temperature level plays an important role in the performance of the braking material. In addition, the tribological and the mechanical properties were found to be temperature sensitive.

scholarly journals High Temperature Tribological Properties of Al2O3/NCD Films Investigated Under Ambient Air Conditions

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 175
Author(s):  
Vitali Podgursky ◽  
Maxim Yashin ◽  
Taivo Jõgiaas ◽  
Mart Viljus ◽  
Asad Alamgir ◽  
...  
Keyword(s):  
Sliding Wear ◽  
Wear Behavior ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Ambient Air ◽  
Dry Sliding Wear ◽  
Wear Volume ◽  
Al2o3 Layer ◽  
The Coefficient Of Friction ◽  
Short Run

Comparative analysis of dry sliding wear behavior of nanocrystalline diamond (NCD) films and NCD films coated with a thin Al2O3 layer (Al2O3/NCD) is the main goal of the present study. Plasma-enhanced chemical vapor deposition (PECVD) and atomic layer deposition (ALD) methods were used to prepare the NCD and alumina films, respectively. Sliding wear tests were conducted at room temperature (RT), 300 and 450 °C in air. Independent of type of specimen, superlubricating behavior with the coefficient of friction (COF) in the range of 0.004‒0.04 was found for the tests at 300 °C. However, the COF value measured on the Al2O3/NCD films in the tests at 450 °C is lower than that for the NCD film. A relatively short run-in period and a stable COF value of about 0.15 were observed at this temperature for the Al2O3/NCD films. The width of the wear scars measured on the Al2O3/NCD films after the tests at 450 °C is significantly smaller in comparison with the NCD film. The apparent wear volume of the wear scar on the NCD film tested at 450 °C was noticeably higher than that on the Al2O3/NCD films.

Sintered Frictional Materials Based on Cu Powders

2013 ◽  
Vol 747 ◽  
pp. 55-58
Author(s):  
Thanyaporn Yotkeaw ◽  
Nattaya Tosangthum ◽  
Rungtip Krataitong ◽  
Monnapas Morakotjinda ◽  
Jirapat Prapai ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Lead Oxide ◽  
Sintering Temperature ◽  
Wear Behavior ◽  
Friction Material ◽  
Natural Sand ◽  
Mechanical And Tribological Properties ◽  
Powder Metallurgical Process ◽  
Hardness Property ◽  
Frictional Materials

Sintered frictional materials (SFMs) were fabricated by using powder metallurgical process. Powder formulations were experimented to investigate effects of Sn, C and ZrO2 additions on mechanical and tribological properties of the sintered composites made for dry frictional materials applications. The developed SFMs consisted of non-lead friction material. Natural sand (SiO2) and ZrO2 were employed instead of lead oxide to provide frictional components. Interrelationships between chemical composition, sintering temperature, friction coefficient, wear behavior and mechanical property of the SFMs have been studied. It was found that sintering temperature affected hardness property of the SFMs. The hardness was also affected by SFM compositions. Friction coefficient increased with increasing ZrO2 content. Addition of natural sand resulted in decrease of the hardness of the SFMs. Graphite also affected hardness and friction coefficient of SFMs containing no sand. Employing prealloyed Cu-Sn powders provided SFMs with better mechanical properties compared to the SFMs made of admixed Cu and Sn powders.

Wear Behavior of Stoichiometric and Nonstoichiometric Zirconia

2016 ◽  
Vol 368 ◽  
pp. 37-40
Author(s):  
Jan Balko ◽  
Monika Tatarková ◽  
Peter Tatarko
Keyword(s):  
Mechanical Properties ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Zirconium Oxide ◽  
Sintering Temperature ◽  
Wear Behavior ◽  
Stoichiometric Composition ◽  
Holding Time ◽  
Different Temperatures ◽  
Alumina Ball

Zirconium oxide samples were sintered at two different temperatures (1250°C and 1450°C) using SPS method with maximum holding time 10 min. to obtain nonstoichiometric composition. Some of the samples were subsequently annealed for 6 hours at 1100°C to obtain stoichiometric composition. Wear rate and friction coefficient were obtained from tribological tests carried out on the UMT3 equipment (Bruker) using two different static partners (zirconia and alumina ball). Main aim of this work is to study the influence of composition and sintering temperature on the wear behavior, friction coefficient and basic mechanical properties.

Dry sliding wear behavior of MoSi2-Mo5Si3-Mo5SiB2 composite at different temperatures and loads

Wear ◽  
2019 ◽  
Vol 428-429 ◽  
pp. 237-245 ◽  
Author(s):  
Huarong Hu ◽  
Yuanjun Guo ◽  
Jianhui Yan ◽  
Jingwen Qiu ◽  
Yi Wang
Keyword(s):  
Sliding Wear ◽  
Wear Behavior ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Different Temperatures

scholarly journals Effects of Gd211 Particles Characteristic in the Precursor Pellets on the Levitation Force of Single-Domain GdBCO Bulks Prepared by the Gd + 011 TSIG Method

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xiaochun Yuan ◽  
Wanmin Yang
Keyword(s):  
Sintering Temperature ◽  
Levitation Force ◽  
Solid Phase ◽  
Single Domain ◽  
Particle Sizes ◽  
The Novel ◽  
Bulk Superconductors ◽  
Lower Porosity ◽  
Different Temperatures ◽  
Average Size

In this paper, single-domain GdBCO bulks have been fabricated by a new Gd + 011 TSIG method with precursor solid phase pellets (PSPPs) of different Gd211 particle sizes and distributions, prepared by solid state reaction with well-mixed (Gd2O3 + BaCuO2) pellets at different temperatures. The novel results indicated that (1) the average size of Gd211 particles in PSPP is monotonically increasing with increasing the sintering temperature up to 1200°C. (2) With increasing the sintering temperature from 950 to 1200°C, the porous ratio and the density of the PSPP are, respectively, monotonically decreasing and increasing. Furthermore when the sintering temperature is less than 1000°C, the porous ratio is higher and the density is lower than the values of the pressed pellets. (3) With increasing the sintering temperature, the average size of Gd211 particles in the GdBCO bulk first decreases and then increases. In addition, the smallest Gd211 particles are obtained in the sample sintered at 1050°C. (4) The maximum levitation force is obtained in the sample sintered at 1150°C with a relatively larger size of Gd211 particles and lower porosity. This result is significant when fabricating high-quality GdBCO bulk superconductors by controlling the porosity, Gd211 particle size, and their distribution characteristic.

Properties of POB reinforced PTFE-based friction material for ultrasonic motors

2017 ◽  
Vol 37 (7) ◽  
pp. 681-687 ◽  
Author(s):  
Qingjun Ding ◽  
Yudan Zhang ◽  
Gai Zhao ◽  
Feng Wang
Keyword(s):  
Friction And Wear ◽  
Adhesion Force ◽  
Wear Behavior ◽  
Friction Material ◽  
Friction And Wear Behavior ◽  
Mechanical And Tribological Properties ◽  
Ultrasonic Motors ◽  
The Coefficient Of Friction ◽  
Scanning Electron ◽  
Ball On Disc

Abstract Polytetrafluoroethylene (PTFE) and its composite coating with various poly-p-oxybenzoyl (POB) proportions was prepared by spray suspensions. The friction and wear behavior were evaluated against a GCr15 steel ball on a ball-on-disc tribometer under dry sliding. The effect of the content of POB on the hydrophobic, mechanical and tribological properties of the PTFE-based coatings and the performances of the corresponding ultrasonic motors (USMs) were studied. Experimental results showed that the optimal content of POB not only increased the hardness, adhesion force and contact angle (CA), but also increased the coefficient of friction and wear resistance of the PTFE coatings. Especially, the wear rate of PTFE coating filled with 15 wt.% POB (3.42×10−4 mm3/N·m) was only a quarter of pure PTFE. The morphologies of the worn surfaces of the PTFE coatings were observed by scanning electron microscopy to discuss the wear mechanism. The mechanical output properties of USMs were the best with filling of 10 wt.% POB into PTFE matrix.

scholarly journals Sliding Wear Behavior of High-Temperature Vacuum-Brazed WC-Co-NiP Functional Composite Coatings

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 88
Author(s):  
Roxana Muntean ◽  
Dragoș-Toader Pascal ◽  
Norbert Kazamer ◽  
Gabriela Mărginean ◽  
Viorel-Aurel Șerban
Keyword(s):  
High Temperature ◽  
Sliding Wear ◽  
Wear Behavior ◽  
Composite Coatings ◽  
Dry Sliding Wear ◽  
Case Hardening ◽  
Functional Coatings ◽  
Wear Rates ◽  
The Coefficient Of Friction ◽  
Case Hardening Steel

The present study aimed to investigate the tribological behavior of high-temperature vacuum-brazed WC-Co-NiP functional coatings deposited on 16MnCr5 case hardening steel. Dry sliding wear resistance was evaluated using a non-conformal ball-on-disk arrangement, at room temperature against 100Cr6 and WC-Co static partners, respectively. Morphological, microstructural, and chemical composition analyses showed a complex, phased structure composed of tungsten carbide, nickel, and hard cobalt-based η-structure. In the testing conditions, the coefficient of friction against 100Cr6 and WC-Co counterparts entered a steady-state value after approximately 1000 m and 400 m, respectively. The wear track analysis revealed phenomena of particles trapped between the sliding bodies, as well as gradual removal of asperities. The calculations of the wear rates proved that the values were strongly influenced by properties of the sliding system, such as crystal structure, stress discontinuities, hardness, and material homogeneity.

Dry sliding wear behavior of Mg2Si/Al composites against automobile friction material

Wear ◽  
2008 ◽  
Vol 264 (7-8) ◽  
pp. 654-661 ◽  
Author(s):  
Q.D. Qin ◽  
Y.G. Zhao ◽  
W. Zhou
Keyword(s):  
Sliding Wear ◽  
Wear Behavior ◽  
Friction Material ◽  
Dry Sliding Wear ◽  
Dry Sliding
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