scholarly journals Structure, Mechanical and Tribological Properties of MoSN/MoS2 Multilayer Films

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 108 ◽  
Author(s):  
Yanlong Fu ◽  
Tengfei He ◽  
Wu Yang ◽  
Jiao Xu ◽  
Bo Mu ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Flow Rate ◽  
Multilayer Film ◽  
Multilayer Films ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Compact Structure ◽  
Flow Rates ◽  
Mechanical And Tribological Properties ◽  
Mos2 Film

MoSN/MoS2 multilayer films were deposited by a sputtering MoS2 target in alternate Ar and Ar/N2 mixed atmospheres with different nitrogen flow rates. The influence of nitrogen flow rates on the microstructure, mechanical and tribological properties of the prepared films were investigated. The multilayer film exhibited the preferred orientation of (002) plane for MoS2 sublayers and amorphous structure for MoSN sublayers. Introducing N2 into the source gas resulted in a much more compact structure for multilayer films due to the suppression of columnar growth of MoS2 film. With the increase of the nitrogen flow rate, the hardness of the multilayer film firstly increased from 2.3 to 10.5 GPa as the nitrogen flow rate increased from 4 to 10 sccm and then turned downwards to 6.5 GPa at 20 sccm. MoSN/MoS2 film deposited with an optimized microstructure exhibited low friction coefficients below 0.03 and a wear life higher than 1.8×105 revolutions in vacuum. Meanwhile, the optimized film showed an ultralow friction coefficient of 0.004~0.01 and wear rate of 4.7 × 10−7 mm3/N·m in an ultrahigh vacuum. Both the enhanced hardness by N-doping and sustainable formed MoS2 tribofilm contributed to the improved tribological property of MoSN/MoS2 multilayer film.

GROWTH STRUCTURE EFFECT ON THE CORROSION RESISTANCE AND MECHANICAL PROPERTIES OF CrNx COATING

2019 ◽  
Vol 27 (01) ◽  
pp. 1950091 ◽  
Author(s):  
JIAOJIAO DU ◽  
HAIBIN ZHOU ◽  
CAIXIA SUN ◽  
HAIJIANG KOU ◽  
ZHONGWEI MA ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Flow Rate ◽  
Steel Substrate ◽  
Face Centered Cubic ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Flow Rates ◽  
Sputtering Deposition ◽  
Growth Structure

A new approach was adopted to improve the corrosion behavior of the chromium nitride (CrNx) hard coating through magnetron sputtering deposition at different nitrogen flow rates. The influence of the nitrogen flow rates on the chemical composition, microstructure, mechanical property and corrosion behavior in artificial seawater of the CrNx coatings was investigated. The results show that with the increase of the nitrogen flow rates, the growth structure of the coatings varied from dense granular growth to coarse columnar growth. Increasing the nitrogen flow rates was helpful to decrease the Cr/N ratio and induce the phase transforming from mixed hexagonal Cr2N and face-centered cubic CrN to single CrN. However, the coatings under different nitrogen flow rates significantly improved the corrosion resistance and hardness of the steel substrate. Furthermore, at high nitrogen flow rate, the coating had high corrosion velocity and low protective capability against the substrate corrosion due to the fast corrosion channels acted by the columnar grain boundaries. While at the middle nitrogen flow rate, the coating with CrN phase, densely granular growth structure and moderate grain size resulted in excellent corrosion resistance and highest hardness.

scholarly journals Effect of Material and Process Variables on Characteristics of Nitridation-Induced Self-Formed Aluminum Matrix Composites—Part 2: Effect of Nitrogen Flow Rates and Processing Temperatures

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1213
Author(s):  
Dae-Young Kim ◽  
Pil-Ryung Cha ◽  
Ho-Seok Nam ◽  
Hyun-Joo Choi ◽  
Kon-Bae Lee
Keyword(s):  
Matrix Composite ◽  
Flow Rate ◽  
Volume Fraction ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composite ◽  
Aluminum Matrix Composites ◽  
Processing Temperature ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Flow Rates

The nitridation-induced self-formed aluminum matrix composite (NISFAC) process is based on the nitridation reaction, which can be significantly influenced by the characteristics of the starting materials (e.g., the chemical composition of the aluminum powder and the type, size, and volume fraction of the ceramic reinforcement) and the processing variables (e.g., process temperature and time, and flow rate of nitrogen gas). Since these variables do not independently affect the nitridation behavior, a systematic study is necessary to examine the combined effect of these variables upon nitridation. In this second part of our two-part report, we examine the effect of nitrogen flow rates and processing temperatures upon the degree of nitridation which, in turn, determines the amount of exothermic reaction and the amount of molten Al in the nitridation-induced self-formed aluminum matrix composite (NISFAC) process. When either the nitrogen flow rate or the set temperature was too low, high-quality composites were not obtained because the level of nitridation was insufficient to fill the powder voids with molten Al. Hence, since the filling of the voids in the powder bed by molten Al is essential to the NISFAC process, the conditions should be optimized by manipulating the nitrogen flow rate and processing temperature.

scholarly journals Cold plasma: an alternative to reduce the viability of Aspergillus flavus conidia in lentil beans

2019 ◽  
Vol 4 (3) ◽  
pp. 21-31
Author(s):  
Marlenne Gómez-Ramírez ◽  
Lizbeth Soto-Ruvalcaba ◽  
Martín Nieto-Pérez ◽  
Norma G. Rojas-Avelizapa
Keyword(s):  
Aspergillus Flavus ◽  
Flow Rate ◽  
Cold Plasma ◽  
Argon Plasma ◽  
Lethal Effect ◽  
Nitrogen Flow ◽  
Log10 Reduction ◽  
Nitrogen Flow Rate ◽  
Flow Rates ◽  
Germination Process

Microbiological food safety is a major issue and the genus Aspergillus is of great interest given the frequency of its toxin contamination in grains. This paper describes the use of cold plasma generated with argon and a mixture of argonnitrogen as a method of sanitizing lentil beans. Lentil beans were sanitized and exposed to Aspergillus flavus conidia then four different experimental sets were prepared, using only argon and a mixture of argon-nitrogen to generate plasma at nitrogen flow rates of 1.2, 0.81 and 0.32 L/min. Each lentil bean was exposed for 5, 10 and 15 min to plasma. Assays were performed in triplicate. Beans not exposed to plasma were used as controls. All plasma treatments caused a lethal effect on A. flavus conidia within exposure periods of 5 to 15 min. The application of argon plasma showed a log10 reduction of 0.81 (84%) after 15 min. The mixture of argon: nitrogen at 0.81 and 0.32 L/min had a higher lethal effect than argon alone. Although lentil beans sterilization was not completely achieved, an important log10 reduction of 1.43 (96.44 %) and 5.53 (99.99 %) of A. flavus conidia was obtained after 15 min of exposure to the plasma generated by argon-nitrogen mixture using nitrogen at flow rates of 0.81 and 0.32 L/min, respectively. Nitrogen flow rate of 0.32 L/min showed a reduction above 3.0 logarithmic units, so this treatment showed a fungicidal activity. The lowest reduction, 0.3 logarithmic units (50.3 %) was observed at a nitrogen flow rate of 1.2 L/min. Additionally, as a consequence of plasma exposure, conidia of A. flavus showed a delay in germination process and also conidia formation was affected. It was concluded that cold plasma could be used as an alternative to sanitize grains and avoid contamination by microorganisms, which cause grain deterioration and affect its nutritional properties.

Study the effect of nitrogen flow rate on tribological properties of tantalum nitride based coatings

2018 ◽  
Author(s):  
Dharmesh B. Chauhan ◽  
Kamlesh V. Chauhan ◽  
Akshay L. Sonera ◽  
Nishant S. Makwana ◽  
Divyeshkumar P. Dave ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Flow Rate ◽  
Tantalum Nitride ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate

Structural State and Mechanical Characteristics of the ZrN Films Prepared by Sputtering

2013 ◽  
Vol 440 ◽  
pp. 9-12
Author(s):  
Chien Cheng Liu ◽  
Kuang I Liu ◽  
Yung Chih Chou ◽  
Yung Mao Cheng ◽  
Chih Lung Lin
Keyword(s):  
Flow Rate ◽  
Diffraction Field ◽  
Nitrogen Flow ◽  
X Ray Diffraction ◽  
Nitrogen Flow Rate ◽  
Flow Rates ◽  
Microstructure Morphology ◽  
Pin On Disk ◽  
Steel Substrates ◽  
Hardness Values

ZrN films were prepared by magnetron sputtering on die steel substrates. The objective of this study was to investigate the effect of nitrogen flow rate on the microstructure ,morphology, nanohardness properties determined by X-ray diffraction, field-emission scanning electron microscope, nanoindentation, and pin-on-disk, respectively. The XRD shows that ZrN has (111) and (200) preferred orientation under lower nitrogen flow rates. The surface of coatings revealed smaller grains and uniform dense under lower nitrogen flow rates. With increasing the nitrogen flow rates, this result showed ZrN films lead to poor mechanical properties and hardness values. However, films consisted of up high ernitrogen flow rate had much lower friction coefficient.

Nanoindentation and Microstructural Evolution Studies of DC Magnetron Sputtered Chromium Nitride Thin Films

2001 ◽  
Vol 672 ◽  
Author(s):  
A.B. Agarwal ◽  
B.A. Rainey ◽  
S.M. Yalisove ◽  
J.C. Bilello
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flow Rate ◽  
Chromium Nitride ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Flow Rates ◽  
Chromium Nitrides ◽  
Deposited Films

ABSTRACTNanoindentation experiments have been performed to assess the mechanical behavior of chromium nitride (CrxNy) thin films sputtered in different deposition geometries and with varying Ar and N2 pressures. The hardness and elastic modulus of chromium nitrides are of great interest with regard to their applications. In the present work, two different deposition geometries, i.e. multi-substrate and confocal, were used to sputter (DC magnetron) a CrxNy layer on Si (100) wafers at varying nitrogen flow rates. The results of the nanoindentation experiments indicate that, over a similar argon and nitrogen regime, the CrxNy films grown in a multi- substrate geometry exhibit higher hardness and elastic modulus on the average than those grown in the confocal geometry. Furthermore, it was found that in the multi-substrate geometry the hardness and elastic modulus of the films were significantly higher than those in the confocally deposited films for a specific regime of the nitrogen flow rate (10-14 sccm). Finally, observations of the mechanical properties trends could be correlated with a higher degree of anisotropic stress for films grown in the multi-substrate in comparison to the confocal geometry.

Assisted Distillation Cleanup of Pesticide Residues in Animal Fats: New Beadless Distillation Tube

1987 ◽  
Vol 70 (5) ◽  
pp. 862-865
Author(s):  
Andrew B Heath ◽  
Robert R Black
Keyword(s):  
Flow Rate ◽  
Pesticide Residues ◽  
Glass Bead ◽  
Glass Wool ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Flow Rates ◽  
Distillation Apparatus ◽  
Animal Fats ◽  
Solvent Washing

Abstract A new assisted distillation tube has been developed which contains no glass beads or glass wool. The sample is injected into the top of the tube, and a septum is not required. Large ground-glass joints (10/ 19) are used at the gas inlet and at the Florisil trap connection for maximum strength. Existing assisted distillation apparatus was easily modified to accept the new tubes. Recoveries of 9 organochlorine pesticides from butter and cattle fat ranged from 87 to 104% at a tube temperature of 230°C and a nitrogen flow rate of 250 mL/min. No significant change occurred in recoveries of 8 of the 9 pesticides after 85 uses of the headless tube. Only the recovery of HCB from butter decreased, from 95 to 80%, after 51 runs. The new tube was compared with the Unitrex glass bead-packed concentric tube at flow rates of 230, 400, and 600 mL nitrogen/min. Recoveries from the Unitrex tube were similar to those of the headless tube for all pesticides except DDT which was significantly lower, indicating incomplete distillation at 250 mL/min and possible partial breakdown at 400 and 600 mL/min. A procedure is introduced for pressurized solvent washing of distillation tubes. This procedure is more efficient than vacuum washing

scholarly journals Influences of Nitrogen Flow Rate on Microstructure, Mechanical and Tribological Properties of WCN Coatings Deposited by HiPIMS

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 481
Author(s):  
Weifeng He ◽  
Yuhui Yang ◽  
Shuqi Huang ◽  
Shuyu Fan ◽  
Min Hu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Tribological Properties ◽  
Flow Rate ◽  
Optical Emission ◽  
Nitrogen Flow ◽  
X Ray ◽  
Mechanical And Tribological Properties ◽  
Average Grain Size ◽  
N2 Flow Rate

Tungsten carbide (WC) and Tungsten carbonitride (WCN) coatings are deposited by reactive high-power impulse magnetron sputtering (HiPIMS) with various nitrogen gas flow rates. The characteristics of discharge current and plasma optical emission of HiPIMS are recorded by oscilloscope (OSC) and optical emission spectroscopy (OES). The results exhibit that the peak discharge currents and the intensities of optical emission spectra lines are significantly influenced by the addition of nitrogen. The elemental concentration, microstructure, mechanical and tribological properties in ambient temperature and high temperature of deposited coatings are investigated by a wide variety of techniques such as energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), nano-indentation measurement, scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and ball-on-disk tribometer. The results show that WC/WCN coatings with different microstructures, mechanical properties and tribological properties have been produced by controlling the flow rate of N2. Meanwhile, with the N2 flow rate increasing from 0 sccm to 24 sccm, (101) diffraction peak shifts to low angle. Moreover, (102) and (110) peaks’ intensities and the angle of (101) peak of β-W2C phase of the deposited WCN coatings decrease and disappear, and the average grain size decreases from 8.9 nm to 6.4 nm. XPS results show that the intensities of C=N, W–N, W–C–N, and N–O peaks increase while the intensity of C–W peak decreases. The deposited coatings change from slight columnar type to a typically dense and featureless structure, and the surface roughness decreases from Ra 11.6 nm at 0 sccm to Ra 5.7 nm at 24 sccm. The variation of nitrogen flow also plays a role in the mechanical properties of the coatings. It is found that the maximum hardness and elastic modulus of 35.6 GPa and 476.5 GPa appear at 16 sccm N2 flow rate. The results of wear tests demonstrate the addition of nitrogen slightly deteriorates tribological properties at room temperature (25 °C), but can remarkably improve tribological properties at high temperature (400 °C) of WC/WCN coatings deposited with an appropriate flow rate of nitrogen.

Effects of nitrogen flow rates on reactively sputtered nanocrystal-(Ti,Al)xN1-x/amorphous-SiyN1-y nanolaminate films

2004 ◽  
Vol 19 (8) ◽  
pp. 2322-2329 ◽  
Author(s):  
Bao-Shun Yau ◽  
Jow-Lay Huang ◽  
Ding-Fwu Lii
Keyword(s):  
Flow Rate ◽  
Target Surface ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Flow Rates ◽  
X Ray ◽  
Nanocrystallite Size ◽  
Compositional Modulation ◽  
Atomic Force ◽  
Transmission Electron

Nanocrystal-(Ti,Al)xN1-x/amorphous-SiyN1-y nanolaminate films were deposited periodically under different nitrogen flow rates. The composition, microstructure and mechanical properties of nanolaminate films were investigated by x-ray photoelectron spectroscope, x-ray diffractometer, scanning and transmission electron microscopy, atomic force microscope, and nanoindentation apparatus. Results indicated that the formation of the compound on the target surface was substantially influenced by the deposition rate, composition and crystallite size of the nanolaminate films. Nanolaminate structure with periodic compositional modulation and sharp interfaces were deposited at different nitrogen flow rate. Smaller nanocrystallite size, round-shaped grain features, smoother surface morphology, higher hardness, and reduced elastic modulus were obtained for nanolaminate films with increasing the nitrogen flow rate.

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