Tribological Properties and Wear Mechanism of Copper-Graphite Composite

2012 ◽  
Vol 472-475 ◽  
pp. 618-621 ◽  
Author(s):  
Li Li Duan ◽  
Xu Ran

Copper-graphite composites were fabricated by spark plasma sintering (SPS) and cold-pressed (CP) processing using a mixture of copper and graphite powders mechanically alloyed. Pin-on-disc wear was used to evaluate the tribological behavior of copper-graphite composites. The results show that the coefficient friction and wear rate decreased considerably with increasing graphite content; with increasing the sintering temperature, the coefficient friction and wear rate just decreased in the same way. XPS analysis of worn surface indicated that better tribological properties are due to a lubricious film covering almost entire worn surface. The presence of this tribolayer improves the friction and wear characteristics when the tribolayer covers almost entire wear surface it effectively restricts metal to metal contact between pin and disc.

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Pranav Dev Srivyas ◽  
M.S. Charoo

Advanced composites are the materials of the new generation. Hence, the focus of the study is to determine the tribological properties of the eutectic Al-Si alloy reinforced with (2, 4, 6, 8, and10 wt. %) of n-Al2O3 against chrome-plated steel ball under dry sliding conditions. The novelty of this work is the fabrication of the composite sample with this elemental composition, which is not done before. Spark plasma sintering (SPS) nonconventional fabrication method is used to fabricate advanced composite samples. Friction coefficient (COF) and wear rate of the composite samples were studied under high load, varying from 50 N to 300 N, using the ball-on-disc tribometer configuration, with other parameters such as stroke, frequency, sliding distance, and sliding velocity remaining constant at 2 mm, 30 Hz, 120 meter, and 0.120 m/s, respectively. Reduction in wear volume for the advanced composite was reported in the range 15.45–44.58% compared to the base alloy (eutectic Al-Si alloy). An increase in friction coefficient was reported in the range 28.80–35.65% compared to the base matrix alloy material. It was also reported that the wear rate increases and the friction coefficient of the composite sample decreases with an increase in load for the tribo-pair. It was observed that an increase in the wt. % of reinforcement influences the friction and wear behavior of the composite. Wear mechanism at high load was characterized by plastic deformation, adhesion, delamination, and abrasion wear. For pre- and postcharacterization of surface and worn tracks, scanning electron microscopy (SEM) electron dispersion spectroscopy (EDS), 3D surface profilometer, and optical microscopy were used. This work aimed to investigate the influence of load on the tribological properties of Al-Si eutectic reinforced n-Al2O3 under dry sliding conditions. Its main objective was to provide a new contribution to the tribological behavior of these composites fabricated using the nonconventional spark plasma sintering method.


2014 ◽  
Vol 1052 ◽  
pp. 115-119
Author(s):  
Xin Le Cheng ◽  
Bao Hong Tian

By using a SPS-30 spark plasma sintering pressing sintering furnace, the Cu-50Mo-WC composites were prepared with four different WC content by spark plasma sintering method (SPS). The wear behavior of the Cu-50Mo-WC composite pin against the QCr0. 5 bronze disc was examined on a pin-on-disc tribotester. The worn surface morphologies of the composite were observed by a scanning electron microscope (SEM). The wear mechanism was investigated briefly.The results show that the WC particles improve the hardness and wear resistance of the composites. The main wear mechanism of the composites is of adhesive wear and abrasive wear. When addition of 1% WC content, the optimal comprehensive properties of the composite is obtained.


2014 ◽  
Vol 59 (4) ◽  
pp. 1263-1268 ◽  
Author(s):  
I. Sulima

Abstract mechanical and tribological properties of sintered 316L stainless steel composites with TiB2 submicroparticles were investigated. The composites were manufactured by Spark Plasma Sintering (SPS). The wear behaviour was studied by using a ball-on-disc wear tester at room temperature. The worn surface were analysed using Scanning Electron Microscopy (SEM). The results indicated that the friction coefficient and the wear resistance of composites with the same content of TiB2 particles depend on the sintering conditions.


2011 ◽  
Vol 672 ◽  
pp. 241-244 ◽  
Author(s):  
Gabriela Sima ◽  
Mihail Mangra ◽  
Oana Gîngu ◽  
Marius Catalin Criveanu ◽  
Bebe Adrian Olei

The paper presents the experimental results regarding the influence of the reinforcing elements on the wear behavior of Al-matrix composites discontinuously reinforced by SiC and Graphite. This antifriction composite material is processed by Reactive Mechanically Alloyed and then by Spark Plasma Sintering technology. In order to optimize the processing technology, especially the sintering parameters, the Spark Plasma Sintering process was applied because of its advantageous aspects: lower sintering temperatures, shorter sintering time and higher properties values of the sintered material vs. the corresponding ones obtained by the classical sintering route. The authors realized a comparative analysis on the wear behavior of the researched composite materials.


2018 ◽  
Vol 70 (9) ◽  
pp. 1699-1705
Author(s):  
Dong Qiang Gao ◽  
Rui Wang ◽  
Wei Chen

Purpose The effect of the load on the tribological properties of Si3N4-hBN sliding against Si3N4 were investigated under dry and water lubrication condition. Design/methodology/approach Using a MMU-5G type pin-on-disc friction and wear tester. Findings Under the dry friction, the wear mechanism was dominated by ploughing and abrasive wear, and the contact status was elastic contact under the load less than 25 N. With the increase of the load, the friction coefficient decreased; the main wear mechanism was fatigue fracture, and the contact status turned into plastic contact. Under water lubrication, effective lubrication film could be produced on the worn surface, and it had a function of fluid lubrication under the load less than 15 N. With the increase of the load, the pin and the disc came into direct contact, and the friction and wear of the pairs were aggravated; the wear mechanism changed from chemical wear into abrasive wear and brittle spalling. Originality/value The study on the effect of the load on the tribological properties of Si3N4-hBN sliding against Si3N4 was investigated under dry and water lubrication condition in the way of contact stress.


Mechanik ◽  
2017 ◽  
Vol 90 (8-9) ◽  
pp. 793-795
Author(s):  
Elżbieta Bączek ◽  
Piotr Putyra ◽  
Marcin Podsiadło ◽  
Barbara Staniewicz-Brudnik

This paper presents the tribological properties of the diamond-impregnated specimens in the grinding process of sandstone materials. Obtained metallic-diamond composites were homogenized in Speed Mixer and sintered by SPS (spark plasma sintering). The matrix was prepared from: Cu-Sn (NAM-40 80/20 containing 20% wt. Sn) and Fe-Cu-Sn powders. After consolidation the diamond-impregnated specimens were tested for density using the hydrostatic method, Rockwell’s hardness using B scale and for wear rate on abrasive sandstone using a testing rig specially designed to simulate the tool application conditions.


2021 ◽  
Author(s):  
Venkatesh Vavilada ◽  
Ashish B Deoghare

Abstract In this present study Al-10% SiC- X % Kaoline (X= 0, 2, 4, 6, 8) HMMC synthesized by spark plasma sintering technique. The fabricated HMMC samples corresponding to maximum compression strength was subjected to tribological investigation under dry, oil and nanofluids lubricating conditions. Nanofluid lubricants were developed by incorporating SiC nanoparticles with weight percentages of 1 wt%, 1.5 wt% and 2 wt% into the soluble oil. The thermal conductivity was found to be increased with increasing the wt % of SiC nanoparticles and the maximum thermal conductivity of 0.771 W/m.K was obtained for the nanofluids with 2 wt% SiC nanofluids. Sliding wear test was conducted on the pin-on-disc tribometer at 40 N load and sliding speed of 1500 r.p.m for a sliding of 180 s. Results reveal that there was a significant effect of the lubricating conditions (dry, oil and nanofluids) on the wear and C.O.F of the HMMC pin surface. The minimum wear of 119 microns and minimum C.O.F of 0.11 was obtained for nanofluid with 2 wt% SiC nanofluid lubricating conditions. SEM analysis of worn surface under dry and soluble oil lubricating conditions reveal the presence of microcracks and delaminations wear. However, worn surface with smooth grooves and absence of microcracks was identified under nanofluid lubricating conditions.


2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.


2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Aswathi A. Narayanan ◽  
R. S. Sudheesh

Hybrid PTFE/epoxy composites are widely used as materials for self-lubricating spherical bearing which are used in a high-temperature environment. In the present work, zirconium diboride (ZrB2) particles are incorporated to enhance high-temperature tribological properties of PTFE/epoxy composites. Pin on disc experiment is conducted with the aid of design of experiments (DOE) using central composite-response surface methodology (RSM). Under a load of 40 N and 1.25 m/s sliding speed, the optimum content 5.95 vol% of PTFE and 5.05 vol% of ZrB2, yields an ultralow coefficient of friction (COF) in conjunction with a low wear rate of the composite. The addition of ultra-high-temperature ceramic ZrB2 particles and solid lubricant PTFE is found to enhance the thermal conductivity and improve the heat transfer thereby reducing contact temperature. The use of optimum composition of the composite is capable of reducing the wear rate and high local temperature due to friction, implying its potential use as a self-lubricating spherical bearing liner material.


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