scholarly journals Effect of sp3 Content on Adhesion and Tribological Properties of Non-Hydrogenated DLC Films

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1911 ◽  
Author(s):  
Chao Li ◽  
Lei Huang ◽  
Juntang Yuan
Keyword(s):  
Friction Coefficient ◽  
Magnetron Sputtering ◽  
Adhesion Strength ◽  
Bias Voltage ◽  
Tribological Properties ◽  
Scratch Test ◽  
Graphite Target ◽  
Transfer Layer ◽  
Xps Spectra ◽  
Pure Graphite

Non-hydrogenated diamond-like carbon (DLC) films with various ratios of sp3/sp2 were prepared on cemented carbide YG8 with DC magnetron sputtering technology. A pure graphite target was selected as the carbon source. Before DLC deposition, a surface etching pretreatment was carried out by mid-frequency magnetron sputtering method, using Ti atoms to improve adhesion strength. The ratios of sp3/sp2 were adjusted by bias voltages. In order to investigate the effect of the ratio of sp3/sp2 on adhesion and tribological properties, Raman spectra, XPS spectra, adhesion scratch test and ball-on-disk dry friction tests were applied. The results indicated that the ratio of sp3/sp2 fluctuated with bias voltage, increasing in the range of 0.74 to 0.98. The adhesion strength decreased from 31.5 to 18.4 N with the increasing ratio of sp3/sp2, while the friction coefficient rose in DLC-Si3N4 and dropped in DLC-Ti6Al4V. For DLC-Ti6Al4V, the oxidation of Ti6Al4V had a greater influence than graphitization of DLC. The hard oxides of Ti6Al4V broke the graphite transfer layer leading to a high friction coefficient. The wear rate was approximately linearly related to bias voltage. The coefficients of the linear regression equation were influenced by different friction materials. The adhesion strength and the friction coefficient were fitted as a function of the ratio of sp3/sp2.

scholarly journals Influence of Applied Bias Voltage on the Composition, Structure, and Properties of Ti:Si-Codoped a-C:H Films Prepared by Magnetron Sputtering

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jinlong Jiang ◽  
Qiong Wang ◽  
Yubao Wang ◽  
Zhang Xia ◽  
Hua Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Magnetron Sputtering ◽  
Bias Voltage ◽  
Tribological Properties ◽  
Structure And Properties ◽  
Applied Bias ◽  
Applied Bias Voltage ◽  
Methane Mixture ◽  
Composition Structure

The titanium- and silicon-codoped a-C:H films were prepared at different applied bias voltage by magnetron sputtering TiSi target in argon and methane mixture atmosphere. The influence of the applied bias voltage on the composition, surface morphology, structure, and mechanical properties of the films was investigated by XPS, AFM, Raman, FTIR spectroscopy, and nanoindenter. The tribological properties of the films were characterized on an UMT-2MT tribometer. The results demonstrated that the film became smoother and denser with increasing the applied bias voltage up to −200 V, whereas surface roughness increased due to the enhancement of ion bombardment as the applied bias voltage further increased. The sp3carbon fraction in the films monotonously decreased with increasing the applied bias voltage. The film exhibited moderate hardness and the superior tribological properties at the applied bias voltage of −100 V. The tribological behaviors are correlated to the H/E or H3/E2ratio of the films.

scholarly journals Effect of Self-Generated Transfer Layer on the Tribological Properties of PTFE Composites Sliding against Steel

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 399 ◽  
Author(s):  
Ting Xie ◽  
Shihao Feng ◽  
Yongheng Qi ◽  
Ailong Cui
Keyword(s):  
Friction Coefficient ◽  
Layer Thickness ◽  
Tribological Properties ◽  
Normal Load ◽  
Wear Test ◽  
Wear Volume ◽  
Functional Requirements ◽  
Transfer Layer ◽  
Sliding Speed ◽  
Ptfe Composites

Coatings are normally employed to meet some functional requirements. There is a kind of self-generated coating during use, such as the transfer layer during sliding, which may greatly affect the tribological behavior. Although the transfer layer has aroused much attention recently, the formation of the transfer layer closely depends on the service conditions, which need to be further studied. In this paper, the effects of sliding speed, normal load, and duration of wear test on the transfer layer thickness during friction of Ni/PTFE (Polytetrafluoroethylene) composites were experimentally investigated. The formation mechanism of transfer layer and the relationships between tribological properties and transfer layer thickness were analyzed in detail. It was found that the transfer layer thickness increased with increases of sliding speed and normal load; and after a period of wear test, the transfer layer thickness remained stable. The transfer layer thickness correlates linearly with the friction coefficient and wear volume of the PTFE composites. With the increase of the transfer layer thickness, the friction coefficient decreased, while the wear volume increased, which means that a uniform, thin, and stable transfer layer is beneficial for the reduction of friction and wear of the polymeric composites.

Characteristics of Palladium Doped Amorphous Carbon Films Fabricated by Unbalanced Magnetron Sputtering System

2021 ◽  
Vol 16 (6) ◽  
pp. 905-910
Author(s):  
Yong Seob Park ◽  
Young-Baek Kim ◽  
Sung Hwan Hwang ◽  
Jaehyeong Lee
Keyword(s):  
Friction Coefficient ◽  
Magnetron Sputtering ◽  
Bias Voltage ◽  
Amorphous Carbon ◽  
Closed Field ◽  
Hydrogenated Amorphous Carbon ◽  
Unbalanced Magnetron Sputtering ◽  
Unbalanced Magnetron ◽  
Dc Bias ◽  
Hydrogenated Amorphous

Generally, hydrogenated amorphous carbon (a-C:H) has been shown to have a low friction coefficient, high hardness, and low abrasive wear rate. In this study, Pd doped hydrogenated amorphous carbon (a-C:H:Pd) fabricated by the closed-field unbalanced magnetron sputtering (CFUBMS) system with two targets of carbon and palladium in Ar/C2H2 plasma. The tribological and lubricant characteristics for a-C:H:Pd fabricated with various DC bias voltage from 0 to −200 V were investigated. We obtained a hardness up to 27.5 GPa and friction coefficient lower than 0.1. The atomic percentage of Pd related to the lubricant properties increased up to 22% at −200 V. In the results, the Pd doping in the a-C:H films improved the tribological and lubricant properties. The friction coefficient value of a-C:H:Pd films was decreased, the hardness and elastic modulus were increased, and also the adhesion properties was improved with the increase of negative DC bias voltage.

Mechanical and Tribological Properties of Multi-Element CrTiAlN Coatings for Dry Cutting Deposited by Magnetron Sputtering Technologies

2010 ◽  
Vol 34-35 ◽  
pp. 610-615
Author(s):  
Zhi Hai Cai ◽  
Ping Zhang ◽  
Jia Wu He
Keyword(s):  
Friction Coefficient ◽  
Magnetron Sputtering ◽  
Tribological Properties ◽  
Composite Films ◽  
Experimental Results ◽  
Wear Volume ◽  
X Ray Diffraction ◽  
Dry Cutting ◽  
Mechanical And Tribological Properties ◽  
Section Structure

Multi-element CrTiAlN coatings are deposited onto YT14 cemented carbide milling cutter by magnetron sputtering in an Ar+N2 mixture. The nano-indenter, scanning electron microscopy, X-ray diffraction and Rockwell indentations were used to investigate the mechanical property, microstructure and adhesion strength of CrTiAlN coatings. And the tribological properties and dry cutting performance of the CrTiAlN coatings were compared with TiN and TiAlN coatings. The experimental results showed that the phase structures of the composite films include Cr, CrN, Cr2N and TiN phases. And the surface crystal grain of CrTiAlN coatings is relative small and the section structure of CrTiAlN coatings was columns crystal structure. It showed better for CrTiAlN coatings on nano-hardness and adhesion compared with TiN and TiAlN coatings. And the friction coefficient of above three kind coatings was about 0.12-0.15. The friction coefficient and wear volume of CrTiAlN coatings appeared lowest among these three kind coatings. Dry cutting experimental results showed that the sequence of cutting life for these coated tools were CrTiAlN＞TiAlN＞TiN.

scholarly journals Deposition and Tribological Properties of Sulfur-Doped DLC Films Deposited by PBII Method

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Nutthanun Moolsradoo ◽  
Shuichi Watanabe
Keyword(s):  
Elastic Modulus ◽  
Friction Coefficient ◽  
Sulfur Content ◽  
Bias Voltage ◽  
Tribological Properties ◽  
Relative Concentration ◽  
High Vacuum ◽  
Ambient Air ◽  
Flow Rate Ratio ◽  
Negative Pulse

Sulfur-doped diamond-like carbon films (S-DLC) fabricated fromC2H2andSF6mixtures were used to study the effects of sulfur content and negative pulse bias voltage on the deposition and tribological properties of films prepared by plasma-based ion implantation (PBII). The structure and relative concentration of the films were analyzed by Raman spectroscopy and Auger electron spectroscopy. Hardness and elastic modulus of films were measured by nanoindentation hardness testing. Tribological characteristics of films were performed using a ball-on-disk friction tester. The results indicate that with the increasing sulfur content, the hardness and elastic modulus decrease. Additionally, by changing the negative pulse bias voltage from 0 kV to−5 kV, the hardness and elastic modulus increase, while the friction coefficient and specific wear rate tends to decrease. Moreover, at a negative pulse bias voltage of−5 kV and flow-rate ratio of 1 : 2, there is considerable improvement in friction coefficient of 0.05 under ambient air is due to the formation of a transfer films on the interface. The decrease in the friction coefficient of films doped with 4.9 at.% sulfur is greater under high vacuum (0.03) than under ambient air (>0.1).

scholarly journals Tribological Properties of Mo2N Films at Elevated Temperature

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 734 ◽  
Author(s):  
Chenkai Liu ◽  
Hongbo Ju ◽  
Lihua Yu ◽  
Junhua Xu ◽  
Yaoxiang Geng ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Friction Coefficient ◽  
Relative Humidity ◽  
Wear Rate ◽  
Magnetron Sputtering ◽  
Tribological Properties ◽  
Relative Intensity ◽  
Weight Fraction ◽  
Reactive Magnetron ◽  
Sputtering System

Mo2N films were synthesized using the reactive magnetron sputtering system in a mixture of argon and nitrogen, and the tribological properties were investigated at different testing temperatures against an Al2O3 counterpart. The relative intensity ratio (RIR) method was used to calculate the weight fraction of the tribo-film (MoO3) on the wear tracks of the films. The results showed that the average friction coefficient first increased from 0.30 at 25 °C to 0.53 at 200 °C, and then decreased to 0.29 at 550 °C, while the wear rate decreased from 2.1 × 10−6 mm3/Nmm at 25 °C to 5.3 × 10−7 mm3/Nmm at 200 °C and then increased to 3.1 × 10−5 mm3/Nmm at 550 °C. The weight fraction of tribo-film was mainly attributed to changes in the average friction coefficient and the wear rate. Besides this, the relative humidity also influenced the tribological properties at 25–200 °C.

scholarly journals Influence of Slight Pressure Variations on the Mechanical and Tribological Properties of Ti/TiAlV/TiAlVN Coatings Produced by Magnetron Sputtering

2018 ◽  
Vol 12 (10) ◽  
pp. 171
Author(s):  
Beatriz Gálviz-García ◽  
D. Torres-Torres ◽  
E. Martínez ◽  
Jhon J. Olaya-Flórez ◽  
Elisabeth Restrepo-Parra
Keyword(s):  
Magnetron Sputtering ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Scratch Test ◽  
Xrd Analysis ◽  
Properties Of Coatings ◽  
Working Pressure ◽  
Force Microscopy ◽  
Mechanical And Tribological Properties ◽  
Steel Substrates

Ti/TiAlV/TiAlV(N) coatings were deposited by D.C magnetron sputtering technique. This experiment was carried out on 316L stainless steel substrates, and it was produced varying the working pressure, in an environment composed by a mixture of Ar/N2. While Ti and TiAlV layers were produced at a constant pressure, TiAlV(N) layers were grown at 0.6, 0.8, 0.9 and 1.0 Pa, for samples M1, M2, M3 and M4, respectively. After the production, morphological, compositional and structural properties of coatings were studied using techniques as x-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and atomic force microscopy (AFM). Next, mechanical and tribological properties such as hardness, Young’s modulus, coefficient of friction, and adherence were evaluated, using nanoindentation, scratch test and ball on disc methods. XRD analysis evidenced that coatings crystallized in a salt rock FCC structure, and the crystallite size tended to increase with the increase of pressure. The XPS analysis allowed to demonstrate the presence of the doublets corresponding to metallic aluminum. Titanium was also found as well as the presence of oxygen as an oxidizing element of the coating.  Regarding to the morphological analysis, it was observed an increase of the roughness when the coatings were grown, compared with the stainless substrates; moreover, no significant influence of the small pressure variation was observed on properties as hardness, coefficient of friction, and critical load.

Influence of Negative Bias Voltage on the Microstructure and Tribological Properties of CrTiAlN Composite Films

2012 ◽  
Vol 155-156 ◽  
pp. 974-978
Author(s):  
Zhi Hai Cai ◽  
Yue Lan Di ◽  
Zhen Yang ◽  
Ping Zhang
Keyword(s):  
Adhesion Strength ◽  
Bias Voltage ◽  
Tribological Properties ◽  
Crystal Size ◽  
Composite Coatings ◽  
Composite Films ◽  
Negative Bias ◽  
Negative Bias Voltage ◽  
Key Factor ◽  
Increase Service Life

By using the multi-ion plating,the CrAlTiN composite films were made on the suface of piston rings to improve its tribological properties and increase service life. The effects of negative bias voltage on morphology, hardness, adhesion strength, microstructure and tribological properties were studied. The results show that the morphology, phases, hardness, adhesion and wearability of the films were varied with negative bias voltage. When the negative bias voltage was at -200V, the hardness, adhesion strength of CrTiAlN coatings reaches maximum and the surface roughness, weightlessness for CrTiAlN composite coatings reaches minimum. And the conclusion can be obtained that the key factor which influences the wearability of the films are the function of the crystal size and adhesion strength together.

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