scholarly journals Tribological Properties of 2D Materials and Composites—A Review of Recent Advances

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1630
Author(s):  
Bodhi R Manu ◽  
Anju Gupta ◽  
Ahalapitiya H Jayatissa
Keyword(s):  
2D Materials ◽  
Polymeric Materials ◽  
Solid Lubricants ◽  
Industrial Applications ◽  
Film Deposition ◽  
Process Conditions ◽  
Boron Compounds ◽  
Liquid Lubricant ◽  
Deposition Parameters ◽  
Solid Film

This paper aims to provide a theoretical and experimental understanding of the importance of novel 2D materials in solid-film lubrication, along with modulating strategies adopted so far to improve their performance for spacecraft and industrial applications. The mechanisms and the underlying physics of 2D materials are reviewed with experimental results. This paper covers some of the widely investigated solid lubricants such as MoS2, graphene, and boron compounds, namely h-BN and boric acid. Solid lubricants such as black phosphorus that have gained research prominence are also discussed regarding their application as additives in polymeric materials. The effects of process conditions, film deposition parameters, and dopants concentration on friction and wear rate are discussed with a qualitative and quantitative emphasis that are supported with adequate examples and application areas and summarized in the form of graphs and tables for easy readability. The use of advanced manufacturing methods such as powder metallurgy and sintering to produce solid lubricants of superior tribological performance and the subsequent economic gain from their development as a substitute for liquid lubricant are also evaluated.

scholarly journals Formation of Solid Lubricants during High Temperature Tribology of Silver-Doped Molybdenum Nitride Coatings Deposited by dcMS and HIPIMS

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1415
Author(s):  
Martin Fenker ◽  
Martin Balzer ◽  
Sabine Kellner ◽  
Tomas Polcar ◽  
Andreas Richter ◽  
...  
Keyword(s):  
High Temperature ◽  
Magnetron Sputtering ◽  
Elevated Temperatures ◽  
Indentation Test ◽  
Solid Lubricants ◽  
Industrial Applications ◽  
Film Deposition ◽  
Molybdenum Oxides ◽  
Molybdenum Nitride ◽  
X Ray

The coating system MoN-Ag is an interesting candidate for industrial applications as a low friction coating at elevated temperatures, due to the formation of lubricous molybdenum oxides and silver molybdates. Film deposition was performed by high-power impulse magnetron sputtering and direct current magnetron sputtering. To facilitate a future transfer to industry Mo-Ag composite targets have been sputtered in Ar/N2 atmosphere. The chemical composition of the deposited MoN-Ag films has been investigated by wavelength dispersive X-ray spectroscopy. Morphology and crystallographic phases of the films were studied by scanning electron microscopy and X-ray diffraction. To obtain film hardness in relation to Ag content and bias voltage, the instrumented indentation test was applied. Pin-on-disc tribological tests have been performed at room temperature and at high temperature (HT, 450 °C). Samples from HT tests have been analyzed by Raman measurements to identify possible molybdenum oxide and/or silver molybdate phases. At low Ag contents (≤7 at.%), coatings with a hardness of 18–31 GPa could be deposited. Friction coefficients at HT decreased with increasing Ag content. After these tests, Raman measurements revealed the MoO3 phase on all samples and the Ag2Mo4O13 phase for the highest Ag contents (~23–26 at.%).

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

Self-Assembly Optical Components

2003 ◽  
Vol 771 ◽  
Author(s):  
Pavel I. Lazarev ◽  
Michael V. Paukshto ◽  
Elena N. Sidorenko
Keyword(s):  
Optical Properties ◽  
Self Assembly ◽  
Crystalline State ◽  
Liquid Crystalline ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
Optical Components ◽  
Crystal Film ◽  
Solid Film ◽  
Thin Crystal

AbstractWe report a new method of Thin Crystal Film deposition. In the present paper we describe the method of crystallization, structure, and optical properties of Bisbenzimidazo[2,1-a:1',2',b']anthra[2,1,9-def:6,5,10-d'e'f']-diisoquinoline-6,9-dion (mixture with cis-isomer) (abbreviated DBI PTCA) sulfonation product. The Thin Crystal Film has a thickness of 200-1000 nm, with anisotropic optical properties such as refraction and absorption indices. X-ray diffraction data evidences a lyotropic liquid crystalline state in liquid phase and crystalline state in solid film. Anisotropic optical properties of the film make it useful in optical devices, e.g. liquid crystal displays.

Stress and Phase Transformation Phenomena in Oxide Films: Real-Time Spectroscopic Measurements

1992 ◽  
Vol 271 ◽  
Author(s):  
Gregory J. Exarhos ◽  
Nancy J. Hess
Keyword(s):  
Phase Transformation ◽  
Applied Pressure ◽  
Oxide Films ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Film Deposition ◽  
Optical Methods ◽  
Fluorescence Emission Spectra ◽  
Line Intensities ◽  
Deposition Parameters

ABSTRACTIn situ optical methods are reviewed for characterization of phase transformation processes and evaluation of residual stress in solution-deposited metastable oxide films. Such low density films most often are deposited as disordered phases making them prone to crystallization and attendant densification when subjected to increased temperature and/or applied pressure. Inherent stress imparted during film deposition and its evolution during the transformation are evaluated from phonon frequency shifts seen in Raman spectra (TiO2) or from changes in the laser-induced fluorescence emission spectra for films containing rare earth (Sm+3:Y3Al5O12) or transition metal (Cr+3 :Al2O3) dopants. The data in combination with measured increases in line intensities intrinsic to the evolving phase are used to follow crystallization processes in thin films. In general, film deposition parameters are found to influence the crystallite ingrowth kinetics and the magnitude of stress and stress relaxation in the film during the transformation. The utility of these methods to probe crystallization phenomena in oxide films will be addressed.

Effect of Niobium Film on Corrosion Resistance of AZ91D Magnesium Alloy

2012 ◽  
Vol 525-526 ◽  
pp. 9-12 ◽  
Author(s):  
Er Bao Liu ◽  
Xiu Fang Cui ◽  
Guo Jin ◽  
Qing Fen Li ◽  
Tian Min Shao
Keyword(s):  
Corrosion Resistance ◽  
Elastic Modulus ◽  
Magnesium Alloy ◽  
Substrate Temperature ◽  
Phase Structure ◽  
Film Deposition ◽  
Negative Bias ◽  
Az91d Magnesium Alloy ◽  
Atomic Force ◽  
Deposition Parameters

The niobium film is prepared by magnetron sputtering on the surface of the AZ91D magnesium alloy. The morphology, phase structure, roughness, nanohardness and elastic modulus of the niobium films were studied by filed emission scanning electron microscope, X-ray diffraction, atomic force microscope and nanoindentation respectively. The influences of film deposition parameters, such as substrate temperature, negative bias and power on the properties of films were investigated. The corrosion resistance of niobium films on magnesium alloy was investigated by electrochemical system. Results show that the microstructure, phase structure, roughness, nanohardness and elastic modulus of the niobium films are determined by power, negative bias and substrate temperature. And the corrosion resistance of magnesium alloy improved obviously when coated with the niobium films.

Possibilities to Apply Friction Stir Processing FSP in Surface Engineering

2021 ◽  
Vol 890 ◽  
pp. 56-65
Author(s):  
Cristian Ciucă ◽  
Lia Nicoleta Boțilă ◽  
Radu Cojocaru ◽  
Ion Aurel Perianu
Keyword(s):  
Aluminum Alloys ◽  
Friction Stir Processing ◽  
Surface Engineering ◽  
Copper Alloys ◽  
Welding Process ◽  
Industrial Applications ◽  
Process Conditions ◽  
Cast Aluminum ◽  
Friction Stir ◽  
Cast Aluminum Alloys

The results obtained by ISIM Timisoara to the development of the friction stir welding process (FSW) have supported the extension of the researches on some derived processes, including friction stir processing (FSP). The experimental programs (the researches) were developed within complex research projects, aspects regarding the principle of the process, modalities and techniques of application, experiments for specific applications, being approached. The paper presents good results obtained by friction stir processing of cast aluminum alloys and copper alloys. The optimal process conditions, optimal characteristics of the processing tools were defined. The complex characterization of the processed areas was done, the advantages of the process applying being presented, especially for the cast aluminum alloys: EN AW 4047, EN AW 5083 and EN AW 7021. The characteristics of the processed areas are compared with those of the base materials. The results obtained are a solid basis for substantiating of some specific industrial applications, especially in the automotive, aeronautical / aerospace fields.

scholarly journals Effect of Plasma Nitriding Process Conditions on Corrosion Resistance of 440B Martensitic Stainless Steel

2014 ◽  
Vol 8 (3) ◽  
pp. 156-159 ◽  
Author(s):  
Magdalena Łępicka ◽  
Małgorzata Grądzka-Dahlke
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Degradation Products ◽  
Plasma Nitriding ◽  
Electrochemical Corrosion ◽  
Industrial Applications ◽  
Process Conditions ◽  
Corrosion Properties ◽  
Dental Instruments ◽  
Increased Risk

Abstract Martensitic stainless steels are used in a large number of various industrial applications, e.g. molds for plastic injections and glass moldings, automotive components, cutting tools, surgical and dental instruments. The improvement of their tribological and corrosion properties is a problem of high interest especially in medical applications, where patient safety becomes a priority. The paper covers findings from plasma nitrided AISI 440B (PN-EN or DIN X90CrMoV18) stainless steel corrosion resistance studies. Conventionally heat treated and plasma nitrided in N2:H2 reaction gas mixture (50:50, 65:35 and 80:20, respectively) in two different temperature ranges (380 or 450°C) specimens groups were examined. Microscopic observations and electrochemical corrosion tests were performed using a variety of analytical techniques. As obtained findings show, plasma nitriding of AISI 440B stainless steel, regardless of the process temperature, results in reduction of corrosion current density. Nevertheless, applying thermo-chemical process which requires exceeding temperature of about 400°C is not recommended due to increased risk of steel sensitization to intergranular and stress corrosion. According to the results, material ion nitrided in 450°C underwent leaching corrosion processes, which led to significant disproportion in chemical composition of the corroded and corrosion-free areas. The authors suggest further research into corrosion process of plasma nitrided materials and its degradation products.

scholarly journals Influence of kaolin filler on the mechanical properties of Luffa cylindrica/ polyester composite

2021 ◽  
Author(s):  
Aliyu Yaro ◽  
Laminu Kuburi ◽  
Musa Abiodun Moshood
Keyword(s):  
Mechanical Properties ◽  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Low Cost ◽  
Microstructural Analysis ◽  
Polymeric Materials ◽  
Weight Fraction ◽  
Industrial Applications ◽  
Luffa Cylindrica ◽  
Polyester Composite

Abstract Polymeric materials are used in different industrial applications because they retain good environmental properties, low-cost, and easy to produce compared to conventional materials. This study investigated the effect of adding kaolin micro-filler (KF) on the mechanical properties of Luffa Fiber (LCF) reinforced polyester resin. Luffa cylindrica fiber treated with 5% NaOH, varied in weight fraction (5, 10, and 15%wt) was used to reinforce unsaturated polyester resin using hand lay-up method, whereas for the hybrid composite kaolin filler were kept constant at 6wt% fraction while the fibers varied as in the mono-reinforced composite. The samples were machined for mechanical and microstructural analysis. Analysis of the result revealed that the addition of kaolin has enhanced greatly the mechanical properties of Luffa-fibre based composites. The result reveal of the microstructure analysis, shows that there is an improvement in fiber-matrix adhesion.

scholarly journals Tribology of 2D Nanomaterials: A Review

2020 ◽  
Author(s):  
Paul С. Uzoma ◽  
Huan Hu ◽  
Mahdi Khadem ◽  
Oleksiy V. Penkov
Keyword(s):  
High Performance ◽  
2D Materials ◽  
Chemical Properties ◽  
Solid Lubricants ◽  
Friction Behavior ◽  
Comprehensive Overview ◽  
Wear Rates ◽  
Recent Developments ◽  
Frictional Coefficients ◽  
Physical And Chemical

The exfoliation of graphene has opened a new frontier in material science with a focus on 2D materials. The unique thermal, physical and chemical properties of these materials have made them one of the choicest candidates in novel mechanical and nano-electronic devices. Notably, 2D materials such as graphene, MoS2, WS2, h-BN, and Black Phosphorus have shown outstanding lowest frictional coefficients and wear rates, making them attractive materials for high-performance nano-lubricants and lubricating applications. The objective of this work is to provide a comprehensive overview of the most recent developments in the tribological potentials of 2D materials. At first, the essential physical, wear, and frictional characteristics of the 2D materials including their production techniques are discussed. Subsequently, the experimental explorations and theoretical simulations of the most common 2D materials are reviewed in regards to their tribological applications such as their use as solid lubricants and surface lubricant nano-additives. The effects of micro/nano textures on friction behavior are also reviewed. Finally, the current challenges in tribological applications of 2D materials and their prospects are discussed.

Characterizing the stress and electrical properties of superconducting molybdenum films

2021 ◽  
Author(s):  
Yeru Wang ◽  
yajie Liang ◽  
Jiao Ding ◽  
Naihui Chen ◽  
Yanling Chen ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Transition Edge Sensor ◽  
Residual Resistivity ◽  
Film Deposition ◽  
Physical Mechanisms ◽  
Deposition Parameters ◽  
Transition Edge ◽  
Sputtering Power ◽  
Correlative Studies ◽  
Deposition Techniques

Abstract In the process of minimizing stress in sputtered Molybdenum (Mo) films for fabricating transition-edge sensor (TES) devices, we have investigated correlations between the stress and film deposition parameters. At a fixed sputtering power, the tensile stress of our film samples decreases toward both low and high ends of Ar pressure, suggestive of two physical mechanisms at work: an “atomic peening” effect at low Ar pressure and the development of voids at high Ar pressure. We have also carried out correlative studies of the stress and electrical properties (including superconducting critical temperature and residual resistivity) of the film samples, and found that the results are complex. We have made extensive comparisons with the published results, and attempted to explain the discrepancies in terms of film deposition techniques, sample preparation and treatment, and dynamical ranges of measurements. It is fairly clear that the microscopic properties, including porosity and disorder, of Mo films may have significant impact on the correlations.

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