Author(s):  
Carl R. Ribaudo ◽  
Chris Aylott ◽  
Dieter Hofmann ◽  
Craig V. Darragh ◽  
Ryan D. Evans ◽  
...  

Scuffing is a severe form of adhesive wear that can occur on gear flanks operating at combinations of high sliding speed and contact stress in marginal lubrication. Engineered Surfaces (ES) refers to the selection, application, and use of certain topographical modification (TM) techniques and thin film coatings applied using advanced physical vapor deposition (PVD) to improve the tribological performance of mechanical components. In this study, the effects of ES technology upon the scuffing resistance of helical gears were empirically determined. Six different treatments of ES technology were tested along with a baseline treatment of uncoated ground surfaces. In the testing, the gear speed was kept constant while the input torque on the gears was incrementally increased until scuffing was observed. Three ES treatments produced statistically significant increases in the scuffing torque relative to the baseline. Increases in mean scuffing torque using ES technology were as high as 89%.


Quimica Hoy ◽  
2012 ◽  
Vol 2 (2) ◽  
pp. 5
Author(s):  
J. Herrera ◽  
D. Martínez ◽  
J. Rodríguez ◽  
R. González

Abrasive wear resistance ofhot extrusion AISI H 13 coated dies used to produce extruded aluminum micro multivoid tubes was studied. In this process, aluminum and dies are constantly under high friction conditions producing premature die wear; aluminum or lubricant adherence on die surface !ayer, is caused by this phenomenon with product rejection as a consequence. The hot extrusion dies most important properties are hot hardness, wear resistant and surface finishing. Extrusion dies coated with hard thin film coatings by physical vapor deposition, PVD and chemical vapor deposition, CVD, were utilized and thermal diffusion treatment asan altemative. The thin film coatings mechanical properties, nano indentation, and SEM surface analysis were performed to characterize coatings and dies. The wear mechanism was determined and it is affected by the die contact surface !ayer finished by electropolishing and the dies coated with thermal diffusion treatment was the most resistan! condition to the wearprocess dueto the presence ofV and Nb carbonitrures.


2014 ◽  
Vol 11 (3) ◽  
pp. 128-136
Author(s):  
Nathaniel Dahan ◽  
Nick Donaldson ◽  
Stephen Taylor ◽  
Nuno Sereno

For short term applications (less than three years), it may be possible to replace traditional long term packaging materials such as titanium with a biocompatible polymer such as PEEK. This paper investigates the use of commercially available thin films to decrease the water vapor permeation rate through the walls of a PEEK package. It was found that most physical vapor deposition (PVD) and plasma assisted chemical vapor deposition (PaCVD) coatings tested did not provide a significant improvement in lifetime, due to the porosity of the films produced. This is mostly linked to the morphology of the films (i.e., growth in columns which are poorly bonded together, creating a porous structure) and is exacerbated by the high surface roughness of the machined substrates. Applying a lacquer before coating reduces this effect significantly, and we found that the time constant of our coated packages was improved by a factor of 2.3. Based on the findings of our group's previous work and this paper, the maximum achievable lifetime of PEEK packages with a thin film coating and desiccant is presented. As an example, a coated cylindrical PEEK package (using atomic layer deposition, ALD) with a uniform wall thickness of 2 mm, an internal cavity size of 1.5 cm3, filled with 20% of desiccant, has a lifetime of 18.8 mo (27.2 mo with 30% of desiccant). This would be sufficient for a range of applications and provide a cheaper and more versatile packaging alternative to traditional packages.


Author(s):  
Mohammad Nur-E-Alam ◽  
Mohammad Khairul Basher ◽  
Mikhail Vasiliev ◽  
Narottam Das

Metallic thin-film materials and nanoparticles (mainly Silver (Ag)-based) are recently being used in many nano-technological applications including sensors, reflective heat-mirror coatings, and antibacterial coatings as well. The physical vapor deposition technique attracts significant attention for Ag-based nanocomposites with tailoring the structural and optical properties of metallic thin films thus allowing further improvements and application possibilities in various existing fields namely electronics, catalysis, magnetics, optics in alongside the environment and health and new emergent fields in, particularly thin-film coatings. This study highlights the preparation, characterization, properties, and possible future application directions of several types of Silver (Ag)-based nanocomposite thin films prepared by using physical vapor deposition techniques.


2021 ◽  
Vol 11 (15) ◽  
pp. 6746
Author(s):  
Mohammad Nur-E-Alam ◽  
Mohammad Khairul Basher ◽  
Mikhail Vasiliev ◽  
Narottam Das

Metallic thin-film materials and nanoparticles (mainly silver (Ag)-based) are recently being used in many nano-technological applications, including sensors, reflective heat-mirror coatings, and antibacterial coatings. The physical vapor deposition technique has attracted significant attention for Ag-based nanocomposites with tailoring of the structural and optical properties of metallic thin films, thus allowing for further improvements and application possibilities in various existing fields, namely electronics, catalysis, magnetics, and optics, alongside the environment and health and new emergent fields, particularly thin-film coatings. This study highlights the preparation, characterization, properties, and possible future application directions of several types of silver (Ag)-based nanocomposite thin films prepared by using physical vapor deposition techniques. The high-temperature (above 300 °C) heat-treated composite layer shows significant spectral shifts; however, distinguishingly notable sizes of nanoparticles are not observed, which indicates that this newly developed composite material can be useful for various coating applications.


2008 ◽  
Vol 24 (3) ◽  
pp. 714-719 ◽  
Author(s):  
X. Tong ◽  
A. Trivedi ◽  
H. Jia ◽  
M. Zhang ◽  
P. Wang

Sign in / Sign up

Export Citation Format

Share Document