Tribological Properties Of DLC Films Research Articles

Enhancing the tribological property of Mo-doped DLC films in methanol using appropriate bias voltage

Methanol is an ideal substitute fuel for oil resources, it has a wide application prospect in internal combustion engines. However, methanol has poor lubricity, resulting in increased frictional power consumption. In this study, Mo-doped diamond-like carbon (MoDLC) film deposition was performed using the magnetron sputtering method to enhance the tribological properties of DLC films in methanol. The relationship between the structure and properties of the films affected by bias voltage was systematically examined to enhance the service performance of the MoDLC coating in methanol. The results confirmed that Mo-doped DLC films exhibited considerable microstructural differences with variable bias, which further verified the performance of the film. The optimised bias voltage (600 V) resulted in the highest sp3 hybridisation bond content in the MoDLC coating, leading to the highest nano-hardness and H/E values. In addition, the 600 V treated MoDLC had a stable friction process and low wear rate (5.2 × 10−8 mm3/(N·m)) in methanol. The wear results showed that abrasive wear was dominant for MoDLC films in methanol, but oxidation wear and corrosion wear cannot be ignored for high-performance MoDLC films.

Influence of the alloying elements on the tribological performance of DLC coatings in different sliding conditions

Reduction of friction and wear at the sliding surfaces are the main concern in several applications. From an extensive list of low friction hard coatings, DLC type is one of the most studied and develop for achieving low wear and friction. The addition of an alloying element is extensively used, since it can change significantly the coatings performance. Therefore, in this research the tribological behaviour of DLC coatings alloyed with different elements was evaluated, since no works comparing the tribological properties of DLC films with approximately the same alloying elements concentration are reported in the literature. The coatings were deposited by physical vapor deposition and alloyed with: tungsten (W), silver (Ag), silicon (Si), silicon and oxygen (SiO), with concentrations of metallic elements between 10 and 15 at. % and a pure DLC coating was also deposited for comparison purposes. The coatings hardness varied between 23 GPa for the pure DLC and 11 GPa for the alloyed with Si and O. The tribological behaviour of the coatings was evaluated by pin-on-disk against 10 mm 100Cr6 steel balls, at room temperature (RT) and 100 °C. The best wear resistance was achieved with the pure DLC and DLC-W for RT tests. At RT the lowest friction was obtained with the DLCSi and DLCSiO coatings. Despite of the low COF values, those coatings displayed the highest specific wear rate values among all the films. This is attributed to the presence of hard SiC particles stick at the ball counterpart which promotes severe abrasion of the coatings surface. The increase of the temperature to 100 °C increases significantly the friction coefficient for the DLC and DLC-W coatings, whilst, for DLC-Ag, DLC-Si and DLC-SiO coatings a slight decrease is noticed. At this temperature DLCAg coating is the more performing due to the formation of a tick tribolayer rich in Ag adhered at the counterpart surface. With this work it was concluded that friction and wear are not directly related, and the third bodies formed on the sliding surfaces have major influence on the tribological performance of the system.

Influences of Ti, Al and V metal doping on the structural, mechanical and tribological properties of DLC films

DLC films are widely used in different engineering products. However, some problems such as inadequate toughness, insufficient adhesion and internal stresses affect their performance. Therefore, we aimed to enhance the mechanical and tribological features of Cp-Ti by metal-free and metal-doped DLC films in this study. Cp-Ti samples were coated with un-doped and Ti, Al and V metal-doped DLC films by PVD. Their properties were investigated by Raman, XPS, XRD, SEM and wear tester. The results revealed that the incorporation of metal in DLC increased the disorder. Ti, Al and V carbides formed on DLC due to bonding of doping elements with carbon. Metal-doping improved the adhesion and decreased the internal stresses and these improvements caused metal-doped films to exhibit better tribological properties than metal-free film.

Tribological Properties of DLC Films with Different Composition

Tribological Properties of DLC Films with Different Composition

Effects of Lubricant Additives on Tribological Properties of DLC Films

Effects of Lubricant Additives on Tribological Properties of DLC Films

エンジンオイル潤滑下におけるAl-Si系合金に対するDLC膜の摺動特性

エンジンオイル潤滑下におけるAl-Si系合金に対するDLC膜の摺動特性

112 境界潤滑下における各種添加元素がDLC膜のトライボ特性に及ぼす影響

112 境界潤滑下における各種添加元素がDLC膜のトライボ特性に及ぼす影響

20413 エンジンオイル潤滑下での各種DLC膜のトライボ特性に関する研究

Diamond-like carbon films are beginning to be used on automobile engine parts because of their excellent friction and wear resistance properties. The engine oil is composed with base oil and some additives. ZnDTP and MoDTC are mainly used as anti-wear additives and friction modifier respectively. These additives show their ability by tribo-chemical reaction on the metal surface. Therefore the mechanism is still unclear how these additives show their ability with DLC which is chemical inertness. In this study, we evaluate the tribological properties of DLC films under engine oil lubricating condition. By coating DLC film on the ball and disk surface, friction coefficient decreased rather than by coating DLC film on the only disk surface under all lubricating condition.

Tribological properties of DLC films against different steels

We studied the effect of mating materials on the tribological properties of DLC film using mating materials of martensite stainless steels (hardened and annealed AISI440C), austenite stainless steel (AISI304), and bearing steels (hardened and annealed AISI52100). The reciprocating sliding tests were performed with ball-on-plate friction tester in dry air. Analyses of friction surface of specimens were carried out using optical microscopy and micro-laser Raman spectroscopy.With the exception of the annealed AISI52100 ball, the friction coefficient of DLC film decreased with increasing normal load. The friction coefficient for the annealed AISI52100 ball showed a high friction coefficient under wide normal load conditions. Analysis using micro-laser Raman spectroscopy showed that the difference between annealed AISI52100 and others materials appears mainly due to structural changes in the film. Tribological properties of DLC film may thus be affected by a property change in mating materials rather than by mating ball hardness.

Effects of Substrate Bias Voltages on Tribological Properties of DLC Films under Rolling-Sliding Contact with High Pressure

Effects of Substrate Bias Voltages on Tribological Properties of DLC Films under Rolling-Sliding Contact with High Pressure

Tribological properties of DLC films prepared by magnetron sputtering

Two kinds of diamond-like carbon films containing Ti, C and Ti, Cr, C were prepared by magnetron sputtering PVD. The microstructure and elemental composition of the films were characterized by atomic-force microscope (AFM) and auger electron spectrometer (AES), the hardness and modulus were analyzed by nano-indentation, and the tribological properties of the DLC films sliding against GCr15 ball at various loads were measured on a universal reciprocating friction and wear tester. It was found that a compact and gradient diamond-like carbon film was formed on the Si surface by magnetron sputtering. Ti, C DLC films showed excellent wear resistance because of higher value of H/E, the friction coefficient was 0.1∼0.2 at various loads and the wear rate was in the level of 10-7mm3/m. Element Cr improved the hardness, the modulus and the roughness, but reduced the wear resistance of Ti, Cr, C DLC films.

G1100-2-3 高面圧転がり滑り接触におけるDLC膜のしゅう動特性([G1100-2]機素潤滑設計部門一般講演(2))

G1100-2-3 高面圧転がり滑り接触におけるDLC膜のしゅう動特性([G1100-2]機素潤滑設計部門一般講演(2))

アルミニウムに対するDLC膜のトライボロジー特性とドライしごき加工用DLCコーティッド金型の寿命(機械要素,潤滑,設計,生産加工,生産システムなど)

アルミニウムに対するDLC膜のトライボロジー特性とドライしごき加工用DLCコーティッド金型の寿命(機械要素,潤滑,設計,生産加工,生産システムなど)

121 DLC膜の摺動特性改善を目的としたレーザー表面テクスチャリング(摩擦・摩耗材料(1),ものづくりにおける基礎研究と先端技術の融合)

121 DLC膜の摺動特性改善を目的としたレーザー表面テクスチャリング(摩擦・摩耗材料(1),ものづくりにおける基礎研究と先端技術の融合)

Effect of the Prepared Proceeding on Mechanical and Tribological Properties of DLC Films

In order to analyze the effect of proceeding on the mechanical and tribological properties of DLC films. Three DLC films samples on single silicon wafers were prepared by CVD method. The changed bias voltages were 300V, 350V, 450V separately. The structure and topography of prepared films were studied by Raman spectroscopy and atomic force microscopy (AFM), respectively. The hardness and elastic modulus together with friction coefficient of DLC films were measured by Tribolab system. According to the Raman spectra, the G and D peak shift to left with the increasing of bias voltage. Nano indent showed that the hardness (H) of the DLC films decreases from 19.63GPa to 18.12GPa with the increasing of bias voltages, and the value of elastic modulus (E) is also behaving the same trend as H from 157.95GPa to 146.95GPa. Friction coefficients of the three samples were measured by nano-scratch method under the constant normal load of 1000uN and the slide velocity of 3 um/sec, the corresponding friction coefficient is 0.0804 for DLC300, 0.0508for DLC350 and 0.0594 for DLC450 separately, which indicates that high hardness materials may not necessarily the perfect frictional material, but compound properties of hardness and elastic modulus

Atomic oxygen resistant behaviors of Mo/diamond-like carbon nanocomposite lubricating films

Mo doped diamond-like carbon (Mo/DLC) films were deposited on Si substrates via unbalanced magnetron sputtering of molybdenum combined with plasma chemical vapor deposition of CH 4/Ar. The microstructure of the films, characterized by transmission electron microscopy and selected area electron diffraction, was considered as a nanocomposite with nano-sized MoC particles uniformly embedded in the amorphous carbon matrix. The structure, morphology, surface composition and tribological properties of the Mo/DLC films before and after the atomic oxygen (AO) irradiation were investigated and a comparison made with the DLC films. The Mo/DLC films exhibited more excellent degradation resistant behaviors in AO environment than the DLC films, and the MoC nanoparticles were proved to play a critical role of preventing the incursion of AO and maintaining the intrinsic structure and excellent tribological properties of DLC films.

Tribological properties of DLC films deposited on polymers

Tribological properties of DLC films deposited on polymers

A Study on the Tribological Properties of DLC Films Deposited with Different Reaction Gases

AbstractDiamond like carbon (DLC) coatings have attracted great attention for use in various applications in automobile industry and machinery because they have excellent properties such as low friction coefficient and ultra high strength. The low friction coefficient of DLC comes from anti-adhesion with other materials, smooth surface, lubrication of graphite structure at the contacting point of films, and the hydrogen content of the films. Many researches have been focused on the microstructure effects on the tribological properties of DLC films but few have been reported on the effect of hydrogen content. In this study, the effect of hydrogen content on the friction coefficient of DLC films has been investigated.DLC films have been deposited on D2 steel by plasma enhanced CVD (Pulsed DC PECVD) method with different precursor gas of C2H2and CH4and different gas pressure. The effects of gas composition on the hydrogen content in DLC films and the resulting tribological properties have been reviewed. Si interlayer was deposited on D2 to improve adhesion of DLC on steel substrates. The characteristics of microstructure were evaluated by Raman spectroscope and composition was measured by RBS and EDS. The tribological behaviors of DLC films were investigated using ball on disk tribometer. The hardness of films was examined by nano-indenter. The failure mechanism of DLC deposited on steel substrates was examined using optical microscope and SEM/EDS. The results showed that the friction coefficient of DLC films deposited with C2H2was 0.06 and that of the film with CH4was 0.15. The friction coefficient improved with decreasing hydrogen content in DLC films.

Structures and tribological properties of diamond-like carbon films prepared by plasma-based ion implantation on Si

DLC films ranging from 5 to 180 nm in thickness have been prepared by plasma-based ion implantation (PBII) with C on Si. The structures of the films were studied with XPS and Raman spectroscopy. The nanohardness and the intrinsic stress of the films were measured. Dry sliding wear experiments have been carried out, using a ball-on-disc tester, to investigate the tribological properties of DLC films against alumina balls, employing various normal applied loads and reciprocating frequencies. For comparison, DLC films prepared by plasma-assisted chemical vapor deposition (PACVD) on Si were also investigated. The results show that the films prepared by PBII exhibit more significant improvement in tribological properties than the films prepared by PACVD because the former present higher sp 3/sp 2 ratio, higher hardness and lower stress than the latter. The effects of the film thickness, the applied loads and the reciprocating frequencies on the tribological properties are also presented.

Tribological Properties of DLC Films Prepared from Different Raw Materials

Tribological Properties of DLC Films Prepared from Different Raw Materials