EVALUATION OF TRANSFORMED LAYER HARDNESS OF DLC COATING AFTER FRICTION TEST

2016 ◽  
Vol 78 (10-3) ◽  
Author(s):  
Nor Azmmi Masripan ◽  
Yosuke Tsukiyama ◽  
Kenji Ohara ◽  
Noritsugu Umehara ◽  
Hiroyuki Kousaka ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Boundary Lubrication ◽  
Scratch Test ◽  
Tribological Performance ◽  
Diamond Like Carbon ◽  
Friction Test ◽  
Friction Behavior ◽  
Sliding Interface ◽  
Dlc Coating

Diamond-like carbon (DLC) provide very excellence performance in term of friction coefficient and wear resistance under boundary   lubrication. the  nano characteristic of the transformed  layer has not  been studied  in terms  of its  hardness  which is believed to  have a significant  effect in the tribological  performance. This study presented the scratch test of the DLC transformed layer was obtained from the AFM scratch test that governs the friction behavior of DLC. As a result, the hardness of the DLC transformed layer depends on the oil temperature, where the sliding interface of DLC softened during the friction test due to graphitization process

Microstructure, nano-mechanical characterization, and fretting wear behavior of plasma surface Cr-Nb alloying on γ-TiAl

2020 ◽  
pp. 135065012093983
Author(s):  
Dongbo Wei ◽  
Fengkun Li ◽  
Xiangfei Wei ◽  
Tomasz Liskiewicz ◽  
Krzysztof J Kubiak ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Behavior ◽  
Wear Test ◽  
Wear Scar ◽  
Fretting Wear ◽  
Friction Behavior ◽  
Plasma Surface ◽  
Nb Alloying

In this study, surface Cr-Nb alloying was realized on γ-TiAl using double glow plasma hollow cathode discharge technique. An inter-diffusion layer was generated under the surface, composed of Cr2Nb intermetallic compounds. After Cr-Nb alloying, the surface nanohardness of γ-TiAl increased from 5.65 to 11.61 GPa. The surface H/E and H3/E2 increased from 3.37 to 5.98 and from 0.64 to 4.15, respectively. Cr-Nb alloying and its effect on fretting wear were investigated. The surface treatment resulted in improved plastic deformation and fretting wear resistance of γ-TiAl. The fretting wear test showed that an average friction coefficient of γ-TiAl against Si3N4 ball was significantly decreased after Cr-Nb alloying. The fluctuation of friction coefficient during running-in stage was significantly improved. The friction behavior of both γ-TiAl before and after Cr-Nb alloying could be divided into distinctive stages including formation of debris, flaking, formation of crack, and delamination. It was observed that the high hardness, resistance to plastic deformation, and fatigue resistance of γ-TiAl after Cr-Nb alloying could inhibit the formation of debris and delamination during friction test. The fretting wear scar area and the maximum wear scar depth were decreased, indicating that the wear resistance of γ-TiAl has been greatly improved after Cr-Nb alloying. The results indicated that plasma surface Cr-Nb alloying is an effective way for improving the fretting wear resistance of γ-TiAl in aviation area.

Preparation of WS2/MoS2/C Composite Films and their Tribological Properties

2009 ◽  
Vol 79-82 ◽  
pp. 711-714
Author(s):  
Lei Zhou ◽  
Gui Lin Yin ◽  
Yu Dong Wang ◽  
Zhen Yu ◽  
Dan Nong He
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Room Temperature ◽  
Composite Films ◽  
Tribological Performance ◽  
Atmospheric Conditions ◽  
Composite Target ◽  
Mos2 Film ◽  
Order Of Magnitude ◽  
The Relationship

WS2/MoS2/C composite lubricating films were prepared in an Ar/C2H2 atmosphere by magnetron reaction-sputtering using a WS2/MoS2 composite target. The relationship between the microstructure and the tribological performance of the films was investigated. The composite film has a compact microstructure, which is shown to have much superior tribological performance with lower friction coefficient and better wear resistance than pure MoS2 film in humid atmospheric conditions at room temperature. An increase in hardness of nearly one order of magnitude was reached, too.

Tribological properties of trimellitates containing polymethacrylates viscosity modifiers

2017 ◽  
Vol 232 (7) ◽  
pp. 882-889 ◽  
Author(s):  
Yan Zhao ◽  
Weimin Li ◽  
Xiaobo Wang ◽  
Jing Wang
Keyword(s):  
Friction Coefficient ◽  
Boundary Lubrication ◽  
Adsorbed Layer ◽  
Physical Property ◽  
Tribological Performance ◽  
Film Forming ◽  
Wide Range ◽  
Viscosity Modifiers ◽  
Lubrication Conditions ◽  
Reducing Properties

In the present work, physical property, film-forming property, and tribological performance of three trimellitates and their blends with polymethacrylates viscosity modifiers were investigated. The results showed that the addition of polymethacrylate can significantly improve the viscosity and low temperature fluidity of the base fluids, while exerting slight influence on the viscosity-temperature properties and film forming performance. Tribological tests showed that under boundary lubrication conditions, polymethacrylate modified lubricants exhibit better friction reducing properties over a wide range of temperature and load. However, under high temperature or high load, the performance is weakened. This phenomenon should be due to the formation and destruction of the physically absorbed layer of the polymethacrylate polymer molecular on the metal surface. Under moderate boundary lubrication conditions, the physically absorbed layer can effectively prevent the direct contact of rubbing surface, resulting in a reduction of friction coefficient, while under more severe boundary lubrication conditions, the adsorbed layer is destroyed and the friction coefficient increases again.

Tribological Performance of Nickel-Plated Regular Hexagonal Texture on a Brass Surface Under Boundary Lubrication

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Xiangbo Chen ◽  
Xiaofang Huang ◽  
Zhenping Wan ◽  
Longsheng Lu ◽  
Zhihui Zhang
Keyword(s):  
Friction Coefficient ◽  
Boundary Lubrication ◽  
Photoelectron Spectroscopy ◽  
Resistance Mechanism ◽  
Electroless Nickel ◽  
Tribological Performance ◽  
Wear Loss ◽  
Cu Alloy ◽  
Brass Surface ◽  
Novel Strategy

Abstract A novel bio-inspired nickel-plated regular hexagonal texture (NPRHT) was proposed and fabricated by photolithography combined with electroless nickel plating to improve the tribological performance of a shaft/bushing bearing under boundary lubrication. The friction coefficient, wear loss, and wear resistance mechanism of the NPRHT that was fabricated on the brass surface were investigated under line contact sliding. It is found that the nickel-plated textured samples show a lower friction coefficient than the non-textured samples with a maximum reduction of 43.6% at a sliding speed of 0.02 m/s. The wear rate coefficient of the nickel-plated textured sample decreases by 42.86% compared with that of the non-textured sample. The energy dispersive spectrometry and X-ray photoelectron spectroscopy analysis confirm that the nickel element is transferred from the nickel-plated textured area to the brass zone, resulting in the formation of a Ni/Cu alloy, NiO and Ni2O3 successively. These three films can improve lubricity, repair wear defects, and protect surfaces from oxidation. The experimental results show that the NPRHT provides a novel strategy to manage the friction and wear of shaft/bushing bearings under boundary lubrication.

Friction and wear behavior of hydrogenated diamond-like carbon coating against titanium alloys under large normal load and variable velocity

2017 ◽  
Vol 69 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Jun Liu ◽  
Zhinan Zhang ◽  
Zhe Ji ◽  
Youbai Xie
Keyword(s):  
Friction Coefficient ◽  
Service Life ◽  
Carbon Coating ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Normal Load ◽  
Diamond Like Carbon ◽  
Content Type ◽  
Friction And Wear Behavior ◽  
Dlc Coating

Purpose This paper aims to investigate the effects of reciprocating frequency, large normal load on friction and wear behavior of hydrogenated diamond-like carbon (H-DLC) coating against Ti-6Al-4V ball under dry and lubricated conditions. Design/methodology/approach The friction and wear mechanisms are analyzed by scanning electron microscope, energy dispersive spectroscopy and Raman spectroscopy. Findings The results show that as reciprocating frequency increases under lubricated conditions, the friction coefficient decreases first and then increases. When the reciprocating frequency is 2.54 Hz, the value of friction coefficient reaches the minimum. The friction reduction is because of the transformation from sp3 to sp2, the formation of transfer layer on Ti-6Al-4V ball and the reduction in viscous friction, whereas the increase of friction coefficient is related to wear. In dry conditions, the friction coefficient is between 0.06 and 0.1. And, the service life of H-DLC coating decreases with the increase in reciprocating frequency and normal load. Research limitations/implications It is confirmed that adding the lubricant could prolong the service life of H-DLC coating and reduce friction and wear efficiently. And, the wear mechanisms under dry and lubricated conditions encompass abrasive wear and adhesive wear. Originality/value The results are helpful for application of diamond-like carbon coating.

Ni-P-Diamond Composite Coating on Friction Shims

2013 ◽  
Vol 652-654 ◽  
pp. 1862-1865
Author(s):  
Hua Chen ◽  
Hai Ying Sun ◽  
Su Qiu Jia
Keyword(s):  
Wear Resistance ◽  
Phase Composition ◽  
Friction Coefficient ◽  
Composite Coating ◽  
Electroless Plating ◽  
Scratch Test ◽  
Friction Coefficients ◽  
Diamond Composite ◽  
Diamond Particles

Ni-P diamond particles (20μm) composite coating on friction shims were prepared by electroless plating. Morphology and phase composition of the composite coating were measured by SEM with EDS and XRD. The friction coefficient of the coating was test with scratch test. The results showed that diamond particles distribution was uniform and not stacked by two steps for 10 min. The diamond particles were half embedded in the Ni-P substrate. The element of the coating was Ni,P,C and the phase composition was Ni and diamond. Adhesion of the composite coating was higher than that of the Ni-P coating. Friction coefficients of the Ni-P coating and Ni-P composite coating were 0.47 and 0.18. Half –naked diamond particles played a pinning role and prevented from wear of the coating to get the big friction coefficient and good wear resistance. This Ni-P composite coating on friction shims would improve friction shims technology and realize the production of localization of friction shims.

Effect of Vanadium Addition on the High-Temperature Friction Behavior in Nanostructured Al–Cr–V–N Films Prepared by UBMS

2020 ◽  
Vol 20 (7) ◽  
pp. 4271-4275 ◽  
Author(s):  
Hyundong Kim ◽  
Sungbo Heo ◽  
Wang Ryeol Kim ◽  
Jun-Ho Kim ◽  
In-Wook Park ◽  
...  
Keyword(s):  
High Temperature ◽  
Friction Coefficient ◽  
Vanadium Content ◽  
Friction Test ◽  
Friction Behavior ◽  
Unbalanced Magnetron Sputtering ◽  
Unbalanced Magnetron ◽  
Reactive Gases ◽  
Tribological Films ◽  
Heating Up

In recent year, vanadium-doped tribological films have become available as possible candidates for self-lubrication at high temperatures. In this work, quaternary Al–Cr–V–N films were deposited onto silicon wafer and WC-Co substrates by an unbalanced magnetron sputtering using high purity (99.99%) CrAl2 and V targets with argon-nitrogen reactive gases. EPMA results revealed that vanadium atoms can incorporated from 0 to 13 at.% into the films. The maximum hardness value was ~32 GPa at vanadium content of 7.1 at.% in the Al–Cr–V–N films. The high-temperature tribometer was used to analysis the friction characteristics of the films with elevated temperature. As a result of the high temperature friction test after heating up to 700 °C, the average friction coefficient decreased from 0.62 to 0.35 with increasing of vanadium contents in the Al–Cr–V–N films. It is concluded that the reduction of the friction coefficient is attributed to the formation of V2O5, which is a Magnéli phase that acts as a lubrication at high temperature.

Observations of Depth-Sensing Reciprocating Scratch Tests of DLC and Nitrogenated-DLC Overcoats on Magnetic Disks

1998 ◽  
Vol 517 ◽  
Author(s):  
T.W. Scharf ◽  
R.D. Ott ◽  
D. Yang ◽  
J.A. Barnard
Keyword(s):  
Wear Resistance ◽  
Elastic Recovery ◽  
Normal Load ◽  
Thick Layer ◽  
Scratch Test ◽  
Film Structure ◽  
Diamond Like Carbon ◽  
Hard Disks ◽  
Depth Sensing ◽  
Scratch Tests

AbstractIn this investigation, the wear durability of existing and candidate protective overcoats and substrates was examined. Specifically, 5 nm thick diamond-like carbon (DLC) and nitrogenated diamond-like carbon (N-DLC) overcoats were deposited by sputtering onto glass, glass-ceramic, and NiP/AlMg substrates. The magnetic medium was a 15 nm thick layer of CoCrPt deposited on a 50 nm thick underlayer of CrV. The wear resistance of the hard disks was determined by a recently developed depth sensing reciprocating scratch test using the Nano Indenter© II. During the scratch tests, a constant normal load of 30 jtN was maintained at an indenter velocity of 2μm/sec. It was found the N-DLC/CoCrPt/CrV/glass disk exhibited the most wear resistance and least amount of plastic deformation after the last wear event. Conversely, the NDLC/CoCrPt/CrV/NiP/AiMg disk displayed the least wear resistance even though the magnitude of the elastic recovery was the greatest. This amount of recovery was influenced by the high elastic modulus of the NiP/AIMg substrate. Consequently, the scratch test failed to isolate the intrinsic properties of the overcoat, however it provided a very powerful means of quantitatively assessing the overall response of the whole magnetic disk. This is more relevant since it simulates the response the disks see in performance. In addition, a discrete amount of nitrogen up to 14 atomic % incorporated into the amorphous network resulted in an increase in overcoat durability compared to the DLC overcoat. This was attributed to an increase in the XPS determined number of N-sp3 C bonded sites in a predominantly N-sp2 C bonded matrix. However, with increasing nitrogen concentrations ≥18%, the film structure was weakened due to the micro-Raman spectroscopy determined formation of terminated sites in the amorphous carbon network since nitrogen failed to connect the sp2 domains within the network.

THE EFFECT OF RESIDUAL STRESS ON THE WEAR PROPERTIES OF DLC COATINGS

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2977-2982
Author(s):  
YOUNG-JUN JANG ◽  
SEOCK-SAM KIM ◽  
JONG-JOO RHA
Keyword(s):  
Residual Stress ◽  
Wear Resistance ◽  
Compressive Residual Stress ◽  
Diamond Like Carbon ◽  
Wear Properties ◽  
Dlc Coatings ◽  
Dlc Coating ◽  
Film Hardness ◽  
Increase Wear Resistance ◽  
Layer Coating

Multi-layer diamond-like carbon (DLC) coating, 150 and 220 nm thick were deposited by negative pulsed d.c. bias induced with magnetron sputtering. The objective of this research is to resolve a wear resistance in terms of DLC coating residual stress and mechanical properties. The bias was controlled from - 200 to 0 V during 10 second with point contacting controller. The surface structure was continuously fabricating to soft and hard-layer during deposition. It was shown that the compressive residual stress and hardness were 0.09, 18 GPa under multi-layer coating condition. The as-deposited DLC coating has a relatively higher wear resistance than unmodified DLC under nanoabrasive wear. It also showed that multi-layer DLC coating had no wear until 400 nN. The decreased residual stress and increased film hardness in the multi-layer coating gave a rise to increase wear resistance.

Sign in / Sign up

Export Citation Format

Share Document