scholarly journals On the Influence of Tribological Properties of AISI 4140 Annealed Steel against Ceramic Counterparts under Dry and Lubricated Conditions and Their Effect on Steel Microstructure

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1275
Author(s):  
Luis D. Aguilera-Camacho ◽  
María T. Hernández-Sierra ◽  
J. Santos García-Miranda ◽  
Karla J. Moreno
Keyword(s):  
Low Cost ◽  
Low Friction ◽  
Steel Microstructure ◽  
Electron Microscopies ◽  
Engineering Ceramic ◽  
Aisi 4140 ◽  
Dry Conditions ◽  
Annealed Steel ◽  
Pin On Disk ◽  
Worn Surfaces

AISI 4140 steel is still one of the most distinguished steels employed in tribological applications because of its low cost, great mechanical properties, and appropriate wear resistance. In this contribution, the tribological performance of AISI 4140 annealed steel against engineering ceramic was analyzed to promote parameters for the application of this steel, especially in systems that are subjected to contact pressures between 490–1240 MPa. Dry and lubricated pin-on-disk experiments were completed at different normal loads. The worn surfaces were analyzed by contact profilometry, optical and scanning electron microscopies, energy dispersive spectroscopy, and microhardness examinations. In dry conditions, a better friction response was found on the steel tested with ZrO2. Friction coefficient and wear rate resulted in reductions up to 60% and 99% compared with those obtained with Al2O3 and Si3N4 counterparts. A strain-hardening phenomenon due to the friction process was observed on the samples tested with ZrO2 and Si3N4, which showed grain refinement and hardness increment on worn surfaces. Therefore, those systems exhibited better wear responses. In lubricated conditions, all counterparts exhibited low friction and wear, but the performance of Al2O3 and Si3N4 was highlighted. The results demonstrate that the performance of AISI 4140 annealed steel under the tested conditions is comparable with that of the same steel with other surface treatments.

scholarly journals The influence of chromium as a diffusive additive in the boronizing treatment of AISI 4140 steel on the corrosion resistance of the coating evaluated by Electrochemical Impedance Spectroscopy (EIS)

2020 ◽  
Vol 318 ◽  
pp. 01040
Author(s):  
Dimitrios I. Zagkliveris ◽  
Azarias Mavropoulos ◽  
Efstathios Ntovinos ◽  
Georgios K. Triantafyllidis
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Industrial Applications ◽  
Pack Cementation ◽  
Boride Phase ◽  
Corrosion Resistant ◽  
Aisi 4140 Steel ◽  
Aisi 4140

A large variety of protective coating is being used in industrial applications to improve the resistance of the metallic substrates against corrosion. The pack-cementation method for boronizing and borochromizing is effective to produce extremely hard and corrosion resistant thick coatings and, additionally, is a low-cost and simple technique. In the present study, AISI 4140 steel specimens underwent boronizing and afterwards chromizing by the pack-cementation method using B4C as boron source and Fe-Cr as chromium source, respectively. In both treatments the appropriate activators were used. After chromizing the boronized substrate, a mixed boride phase FeCrB was formed, as it was confirmed by X-ray Diffractometry (XRD). The boronized and the borochromized specimens were subjected to Electrochemical Impedance Spectroscopy (EIS). From the analysis of the frequency response of the coating systems (Bode and Nyquist display), the conclusion that the borochromized specimens were significantly more corrosion resistant was extracted. Finally, data of optical and electron microscopy contribute to the validity of the conclusions.

Low friction bio-inspired polydopamine/polytetrafluoroethylene coating performance in hydrodynamic bearings

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Marius Rutkevičius ◽  
Jimmy Dong ◽  
Darren Tremelling ◽  
Julia Viertel ◽  
Samuel Beckford
Keyword(s):  
Large Scale ◽  
Journal Bearing ◽  
Low Cost ◽  
Optical Microscope ◽  
Polymer Coatings ◽  
Industrial Applications ◽  
Low Friction ◽  
Coating Performance ◽  
Content Type ◽  
Coating Delamination

Purpose Low friction polymer coatings able to withstand high loadings and many years of continuous operation are difficult to formulate at low cost, but could find many applications in industry. This study aims to analyze and compare friction and wear performance of novel polydopamine/polytetrafluoroethylene (PDA/PTFE) and traditional tin Babbitt coatings applied to an industrial journal bearing. Design/methodology/approach This paper tested PTFE based coating, co-deposited with PDA, a biopolymer allowing sea mussels to adhere to ocean rocks. This coating was deposited on flat steel substrates and on a curved cast iron hydrodynamic journal bearing surface. The flat substrates were analyzed with a tribometer and an optical microscope, while the coated bearing liners were tested in an industrial laboratory setting at different speeds and different radial loads. Findings PDA/PTFE coating showed 2-3 times lower friction compared to traditional tin Babbitt for flat substrates, but higher friction in the bearing liners. PDA/PTFE also showed considerable wear through coating delamination and abrasion in the bearing liners. Research limitations/implications Five future modifications to mitigate coating flaws are provided, which include modifications to coating thickness and its surface finish. Originality/value While the novel coating showed excellent results on flat substrates, coating performance in a large scale bearing was found to be poor. This study shows that coating preparation needs to be improved to avoid frictional losses and unwanted damage to bearings. We provide several routes that could improve coating performance in industrial applications.

Performance Evaluation of Magnetohydrodynamic Bearing

2005 ◽  
Author(s):  
H. Hirani ◽  
P. Samanta
Keyword(s):  
High Speed ◽  
Permanent Magnets ◽  
Magnetic Levitation ◽  
Hydrodynamic Lubrication ◽  
Low Cost ◽  
Low Friction ◽  
Oil Flow ◽  
Hybrid Bearing ◽  
Commercial Applications ◽  
Structural Simplicity

The present paper introduces a concept of hydrodynamic-permanent-magnetic hybrid bearing. The hybrid bearing uses repulsive force between permanent magnets and fluid force developed due to relative speed in a single assembly arrangement. Repulsive type passive magnetic levitation has advantage of minimum starting torque. Hydrodynamic lubrication mechanism has advantage of low friction at medium and high speed. This hybridization will be an attractive choice in commercial applications for its low cost, structural-simplicity and no metal-to-metal contact. An experimental setup is designed and developed to investigate the performance characteristics of proposed concept of hybrid bearing. Minimum film thickness, oil flow rate, and temperature rise are recorded at various speed- and load- conditions. Results are plotted to demonstrate the behavior of hybrid bearing arrangement.

scholarly journals Development of low-friction and wear-resistant surfaces for low-cost Al hot stamping tools

2015 ◽  
Vol 21 ◽  
pp. 05009 ◽  
Author(s):  
Y. Dong ◽  
D. Formosa ◽  
J. Fernandez ◽  
X. Li ◽  
G. Fuentes ◽  
...  
Keyword(s):  
Friction And Wear ◽  
Low Cost ◽  
Hot Stamping ◽  
Low Friction ◽  
Wear Resistant

Carbon Based Coatings for Hermetic Compressor Applications

2014 ◽  
Vol 89 ◽  
pp. 21-30
Author(s):  
Jose Daniel Biasoli de Mello
Keyword(s):  
Surface Engineering ◽  
Low Cost ◽  
Constant Load ◽  
High Wear Resistance ◽  
Tribological Behaviour ◽  
Low Friction ◽  
Dlc Coating ◽  
The Usa ◽  
Hermetic Compressor

Household refrigeration represents 17.3% of home energy consumption in the USA and 47% in Brazil. This article overviews a multidisciplinary approach to develop a traditional hermetic compressor (oil lubricated, with several rotating parts), into an oil-less, linear motion, innovative compressor, with improved efficiency, versatility and sustainability. This involves the development of surface engineering processes combining purpose-oriented phases applied to soft substrates to achieve high wear resistance and load support and low friction coefficient. Initially, the role of the environment (air, CO2 and R600a) on the tribological behaviour of a commercially available Si-rich multifunctional DLC coating deposited on AISI 1020 steel is illustrated. In sequence, the influence of the thickness of different layers (DLC and CrN) on sliding wear is analysed. Results are presented using an original approach (3D triboscopic maps) for two distinct configurations (increasing load and constant load) and findings are confronted with numerical simulations using Film Doctor®. Finally, a low cost process to obtain a multifunctional coating (different nitrided layers + DLC) is described, which uses a unique thermal cycle reactor capable of coating parts in industrial scale with reduced cost.

ADDASAT Development Plan for the Attitude Control System

2013 ◽  
Vol 436 ◽  
pp. 47-53
Author(s):  
Radu D. Rugescu ◽  
Mihai Al. Barbelian ◽  
Efim Micu
Keyword(s):  
Control System ◽  
Attitude Control ◽  
Low Cost ◽  
Environmental Policies ◽  
Laboratory Model ◽  
Land Resources ◽  
Attitude Control System ◽  
Low Friction ◽  
Orbital System ◽  
Real Scale

As a part of the ORVEAL project, a real scale laboratory model of the inertial platform for ADDASAT is developed by the joint ADDA and UPB teams, ensuring the capability of a three-axis attitude control demonstration in the ground laboratory that simulates weightlessness by low friction bearings. The study is part of the larger ADDA-UPB program for developing the low cost NERVA orbital system for applications in enhanced environmental policies and land resources surveillance. The ORVEAL research is granted by Romanian UEFISCDI financing authority.

scholarly journals On the Shape-Selected, Ligand-Free Preparation of Hybrid Perovskite (CH3NH3PbBr3) Microcrystals and Their Suitability as Model-System for Single-Crystal Studies of Optoelectronic Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3057
Author(s):  
Ulrich Johannes Bahnmüller ◽  
Henning Kuper ◽  
Tobias Seewald ◽  
Yenal Yalҫinkaya ◽  
Jörg August Becker ◽  
...  
Keyword(s):  
Single Crystal ◽  
Low Cost ◽  
Model System ◽  
Spatially Resolved ◽  
Aerosol Process ◽  
Hybrid Perovskite ◽  
Ligand Free ◽  
Dry Conditions ◽  
Shape Property ◽  
Underlying Processes

Hybrid perovskite materials are one of the most promising candidates for optoelectronic applications, e.g., solar cells and LEDs, which can be produced at low cost compared to established materials. Although this field of research has seen a huge upsurge in the past decade, there is a major lack in understanding the underlying processes, such as shape-property relationships and the role of defects. Our aerosol-assisted synthesis pathway offers the possibility to obtain methylammonium lead bromide (MAPbBr3) microcrystals from a liquid single source precursor. The differently shaped particles are aligned on several substrates, without using a directing agent or other additives. The obtained particles show good stability under dry conditions. This allows us to characterize these materials and their pure surfaces at the single-crystal level using time- and spatially resolved methods, without any influences of size-dependent effects. By optimizing the precursor for the aerosol process, we were able to eliminate any purification steps and use the materials as processed. In addition, we performed theoretical simulations to deepen the understanding of the underlying processes in the formation of the different crystal facets and their specific properties. The model system presented provides insights into the shape-related properties of MAPbBr3 single crystals and their directed but ligand-free synthesis.

scholarly journals Development, Kinematic Modeling and Analysis of 3 (DoF) Pneumatic Gantry Robot

2020 ◽  
Vol 5 (6) ◽  
pp. 646-650
Author(s):  
Awad Eisa G. Mohamed ◽  
Abuobeida Mohammed Elhassan
Keyword(s):  
Controller Design ◽  
Low Cost ◽  
Weight Ratio ◽  
Friction Model ◽  
Pneumatic Cylinder ◽  
Kinematic Modeling ◽  
Low Friction ◽  
Modeling And Analysis ◽  
Gantry Robot ◽  
Pneumatic Cylinders

Low friction pneumatic cylinders are now being considered in applications for which only electric motors or hydraulics were previously considered suitable. One potential application of low friction pneumatics is robotic for metallurgical operations where the high power to weight ratio and low cost could be exploited. As part of an ongoing project to develop a pneumatic robot, this paper presents the kinematic analysis of pneumatic cylinder characteristics that simplifies controller design. Using mathematical modeling and simulation, non-linearity of modern pneumatic systems have been investigated. The derived models give an excellent representation of the system, despite the inclusion of a simplified friction model.

Analysis of the Contribution of Adhesion and Ploughing to Shoe-Floor Lubricated Friction in the Boundary Lubrication Regime

2011 ◽  
Author(s):  
Caitlin Moore ◽  
Kurt Beschorner ◽  
Pradeep L. Menezes ◽  
Michael R. Lovell
Keyword(s):  
Coefficient Of Friction ◽  
Boundary Lubrication ◽  
Ambient Conditions ◽  
Lubrication Regimes ◽  
Lubrication Regime ◽  
Material Hardness ◽  
Lubrication Layer ◽  
The Coefficient Of Friction ◽  
Dry Conditions ◽  
Pin On Disk

Slip and fall accidents cost billions of dollars each year. Shoe-floor-lubricant friction has been shown to follow the Stribeck effect, operating primarily in the boundary and mixed-lubrication regimes. Two of the most important factors believed to significantly contribute to shoe-floor-lubricant friction in the boundary lubrication regime are adhesion and ploughing. Experiments were conducted using a pin-on-disk tribometer to quantify adhesion and ploughing contributions to shoe-floor friction in dry and lubricated conditions. The coefficient of friction between three shoe materials and two floor materials of different hardness and roughness were considered. Experiments were conducted under six lubricants for a sliding speed of 0.01 m/sec at ambient conditions. It was found that the contribution of adhesion and ploughing to shoe-floor-lubricant friction was significantly affected by material hardness, roughness, and lubricant properties. Material hardness and roughness are known to affect adhesion, with increased hardness or increased roughness typically resulting in decreased adhesion. The smoothest shoe material, while also being the hardest, resulted in the greatest adhesional contribution to friction. The roughest material, while also being the softest, resulted in the lowest adhesional contributions under dry conditions. Canola oil consistently resulted in the lowest percent of full adhesion and water consistently resulted in the highest percent of full adhesion, presumably due to the thickness, of the boundary lubrication layer. Ploughing contribution was dependent upon the hardness of the shoe and floor materials. A positive correlation was found between the shoe and floor hardness ratio and ploughing coefficient of friction.

Tribological Behavior of a Polyester Composite System under Severe Wear Conditions

2019 ◽  
Vol 813 ◽  
pp. 453-458
Author(s):  
Massimo Durante ◽  
Luca Boccarusso ◽  
Fabrizio Memola Capece Minutolo ◽  
Pier Paolo Paradiso ◽  
Marco Marlia ◽  
...  
Keyword(s):  
Composite System ◽  
Wear Behavior ◽  
Physical And Mechanical Properties ◽  
Tribological Behaviour ◽  
Low Friction ◽  
Severe Wear ◽  
Synthetic Fibers ◽  
Polyester Composite ◽  
Composite Engineering ◽  
Pin On Disk

This work aims on the study of the wear resistance of a commercial polyester composite system under severe wear conditions. It is an example of composite engineering material manufactured from synthetic fibers and thermosetting resins with appealing physical and mechanical properties that make it very interesting for products like sheets, rods, tubes, flange, washers and wear ring. In order to make it suitable for applications where damage by metal roll surfaces can occur, the study of the wear behavior under specific conditions is then necessary. At this aim, a detailed experimental campaign, including tribological tests and microgeometrical measurements, was carried out. In particular, the tribological behaviour was studied through the pin-on-disk tests conducted at 209 mm/s as peripheral speed under an applied load comprising in the range of 10 - 70 N. The tests were followed by microgeometrical measurements by using a confocal microscope in order to critically observe the wear tracks, evaluate their depth, width and then to calculate the final less of volume. The results proved that the wear mechanisms founded for the composite under investigation differ from those commonly associated to metals; the surface asperities of the fibres allow to hold the lubricant inside the surface and thus assist in the maintenance of a continuous film on the working surface involving in very low friction coefficient.

Sign in / Sign up

Export Citation Format

Share Document