scholarly journals Friction and Wear Mechanisms of Cu/ta-C Coatings Under PAO-4 and PAO-4 with MoDTC Lubrication

2020 ◽  
Vol 01 (04) ◽  
pp. 183-187
Author(s):  
Decelyne Elly Binjua ◽  
Seock-Sam Kim ◽  
Young-Jun Jang ◽  
Jong-Kuk Kim
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Friction And Wear ◽  
Vacuum Arc ◽  
Dlc Coatings ◽  
Base Oil ◽  
Tetrahedral Amorphous Carbon ◽  
Friction And Wear Mechanisms ◽  
Alpha Olefin ◽  
Filtered Cathodic Vacuum Arc

The tribological behavior of various types of DLC coatings in formulated and non-formulated lubricants are needed for proper usage of these coatings. In this research, the friction and wear mechanism of four different DLC coatings in poly-alpha-olefin type 4 (PAO-4) with and without MoDTC were investigated using ball-on-disc tribometer. One ta-C (tetrahedral amorphous carbon) and three Cu/ta-C (copper doped ta-C) with different sputter power of 50 W, 150 W, and 200 W coatings were deposited on silicon wafers by using FCVA (filtered cathodic vacuum arc) technique for this research. The results indicate that ta-C coating on silicon wafer has the lowest average friction coefficient (CoF) and better wear resistance than Cu/ta-C coating when lubricated under PAO-4 oil with MoDTC. Cu/ta-C with sputter powers of 150 W and 200 W exhibited the highest average friction coefficient under PAO-4 oil with MoDTC. Meanwhile, the average CoF for all samples were similar under PAO-4 base oil. In terms of wear, ta-C coating showed the highest wear rate under PAO-4 base oil then followed by Cu/ta-C with sputter power of 50 W. Nonetheless, Cu/ta-C with sputter powers of 150 W and 200 W exhibited significantly low wear rate under PAO-4 base oil compared to PAO-4 oil with MoDTC.

scholarly journals Influence of WS2Nanopowder Addition on Friction Characteristics of ta-C Coating by FCVA Method

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Si-Geun Choi ◽  
Yong-Joong Lee ◽  
Young-Jun Jang ◽  
Dawit Zenebe Segu ◽  
Seock-Sam Kim ◽  
...  
Keyword(s):  
Raman Spectrum ◽  
Friction Coefficient ◽  
Tribological Behavior ◽  
Vacuum Arc ◽  
Particle Sizes ◽  
Friction Test ◽  
Alpha Olefin ◽  
Filtered Cathodic Vacuum Arc ◽  
Nano Size ◽  
Lubrication Conditions

The influence of nano-sizeWS2powders on the tribological behavior of ta-C coatings by the filtered cathodic vacuum arc (FCVA) method under boundary lubrication conditions has been investigated. In order to characterize and understand tribological behaviors of nano-sizeWS2powders added to the synthetic oil (poly-alpha-olefin 6), lubricants with different mixture ratios, ranging from 2 to 8 wt%, have been prepared. ta-C coatings fabricated by FCVA method showed that the G-peak in the obtained Raman spectrum was shifted from 1520 to 1586 cm−1, indicating the sp3content increased for samples with the thickness of 156 nm. The average friction coefficient decreased proportionally as the nano-sizeWS2compositions increased up to 4 wt% in PAO6. After the friction test, structures and particle sizes ofWS2phases were also precisely characterized by using XRD and SEM.

Friction and Wear Behaviors of Solid Lubricants/Polyimide Composites in Liquid Mediums

2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Alkaline Solution ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Polyimide Composites ◽  
Inorganic Fillers ◽  
Ptfe Composites

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.

FCVA-Synthesized Tetrahedral Amorphous Carbon Films for Biomedical Applications

2007 ◽  
Vol 336-338 ◽  
pp. 1577-1580 ◽  
Author(s):  
Chuan Lin Zheng ◽  
Wu Bao Yang ◽  
X. Chang
Keyword(s):  
Amorphous Carbon ◽  
Biomedical Applications ◽  
Pure Titanium ◽  
Carbon Films ◽  
Vacuum Arc ◽  
Negative Bias Voltage ◽  
Tetrahedral Amorphous Carbon ◽  
In Vitro Measurements ◽  
Filtered Cathodic Vacuum Arc

Tetrahedral amorphous carbon (ta-C) films were deposited onto Si(100) wafers by using filtered cathodic vacuum arc technique (FCVA). The influence of the negative bias voltage applied to substrates on film structures was studied by Raman spectroscopy, X-ray photoemission spectroscopy (XPS). The ta-C films showed maximal sp3 fractions 87%, the hardness and elastic modulus of the ta-C film is 72 and 480 GPa, respectively. In vitro measurements of contact angle and platelet adhesion were applied to evaluate the biocompatibility of the ta-C films in comparison with that of NiTi, 316L and pure titanium. The results show that the ta-C films have hydrophobicity and exhibit better hemocompatibility which are very suitable for biomedical applications.

scholarly journals Development of Highly Hydrogenated DLC Coatings for Solid Lubricant Applications in Space

2005 ◽  
Author(s):  
A. Vanhulsel ◽  
R. Jacobs ◽  
K. Van Acker ◽  
E. Roberts ◽  
F. Velasco ◽  
...  
Keyword(s):  
Wear Rate ◽  
Friction And Wear ◽  
Applied Load ◽  
Solid Lubricant ◽  
Solid Lubricants ◽  
Ambient Atmosphere ◽  
Test Environment ◽  
Load Range ◽  
Dlc Coatings ◽  
Aisi 52100 Steel

The development of advanced solid lubricants is of considerable importance to space tribology. The most common solid lubricant coatings today are based on MoS2, lead or PTFE. However, none of these coatings can simultaneously fulfill all specifications, with regard to friction and wear, under ambient atmosphere and in vacuum. Consequently research is currently being aimed at further improvements in advanced solid lubricant coatings. One approach is to optimize Diamond Like Carbon (DLC) coatings to meet the specifications. In this study, the feasibility of highly hydrogenated DLC coatings (∼ 50 at% hydrogen) for solid lubricant applications is assessed. The coatings were deposited on AISI 52100 steel substrates and tested in ball-on-disc tribometers in air, vacuum and dry nitrogen environments. It was found that the test environment has the most decisive effect on both friction and wear rate, while these parameters are only slightly affected by varying the applied load under a given atmosphere. It was concluded that highly hydrogenated DLC coatings are capable of yielding ultra-low friction values in vacuum (μ = 0.008). The average friction coefficient range obtained in humid air, dry nitrogen and vacuum for the range of applied loads were respectively 0.22 to 0.27, 0.02 to 0.03, and 0.007 to 0.013. Coating lifetime was over 100 000 cycles for the entire load range tested in air and nitrogen, but was affected by the applied load as far as tests in vacuum are considered. The specific wear rate was lower than 1×10–5 mm3 N-1 m-1 under all test conditions, which was considered favourable.

Water Absorption, Friction and Wear Behaviors of Polypropylene Composites Filled with Hydroxyapatite

2017 ◽  
Vol 733 ◽  
pp. 60-64
Author(s):  
Munir Tasdemir ◽  
Ozkan Gulsoy
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Water Absorption ◽  
Polymer Composites ◽  
Friction And Wear ◽  
Wear Properties ◽  
Polypropylene Composites ◽  
Friction And Wear Properties

In the present work, the friction and wear properties of Polypropylene (PP) based composites filled with Hydroxyapatite (HA) particles were studied. Fillers contents in the PP were 10, 20, and 30 wt%. The effects of hydroxyapatite ratio on the water absorption, friction and wear properties of the polymer composites is presented. The result showed that the addition of HA to the composite changed the water absorption, friction coefficient and wear rate.

scholarly journals Fabrication and Tribological Properties of Copper Matrix Solid Self-Lubricant Composites Reinforced with Ni/NbSe2 Composites

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1854
Author(s):  
Fei-xia Zhang ◽  
Yan-qiu Chu ◽  
Chang-sheng Li
Keyword(s):  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Copper Matrix ◽  
Wear Properties ◽  
Disk Friction ◽  
Friction Reducing ◽  
Properties Of Composites

This paper presents a facile and effective method for preparing Ni/NbSe2 composites in order to improve the wettability of NbSe2 and copper matrix, which is helpful in enhancing the friction-reducing and anti-wear properties of copper-based composites. The powder metallurgy (P/M) technique was used to fabricate copper-based composites with different weight fractions of Ni/NbSe2, and tribological properties of composites were evaluated by using a ball-on-disk friction-and-wear tester. Results indicated that tribological properties of copper-based composites were improved by the addition of Ni/NbSe2. In particular, copper-based composites containing 15 wt.% Ni/NbSe2 showed the lowest friction coefficient (0.16) and wear rate (4.1 × 10−5 mm3·N−1·m−1) among all composites.

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