Advanced Industrial Lubricants and Future Development Trends of Tribo-Systems for Tribological Performance Evaluation

A special issue of Lubricants (ISSN 2075-4442).

Deadline for manuscript submissions: closed (30 November 2022) | Viewed by 29148

Special Issue Editors


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Guest Editor
Innovation Technology Consulting Inc., Glenview, IL 60026, USA
Interests: automotive lubricants; driveline lubrication; industrial lubricants; EV/hybrid components; thermal management coolants; tribological performance testing; nanofluids; energy storage materials; fuel cell applications
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Guest Editor
Department of Mechanical and Materials Engineering, Portland State University, Portland, OR, USA
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Guest Editor
Laboratory of Physical Materials Science, Institute of Physical Materials Science, Russian Academy of Sciences, Siberian Branch, Ulan-Ude, Russia
Interests: thermal-chemical treatment; boriding; boroaluminizing; electron-beam procesing; wear
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

This Special Issue is the second part of “Industrial Tribo-Systems and Future Development Trends”.

The global automotive and manufacturing industries are facing higher energy costs, more legislative pressure, and an ever-increasing “green” environmental awareness to achieve energy efficiency and environmental sustainability. Prompted by these global challenges, the strong focus on fuel efficiency in most automotive markets is leading to changes in powertrain technologies to meet energy sustainability and environmental demands. In addition, industrial and manufacturing machinery are facing a new development trend towards more energy-efficient systems, higher power densities, and higher loading operations leading to meet the constant demand of higher durability and reliability requirements for more severe conditions such as construction, mining, and forestry and manufacturing environments. Thus, durability and reliability are the most important performance factors for both industrial equipment and heavy-duty machinery. The lubrication market is heavily focused on producing higher quality and better performing lubricants that meet the ever-changing demands of operating in extreme temperature conditions. Whether it is a cold, foggy morning or a hot, dry, dusty afternoon, these conditions will affect the performance of the industrial lubricants. Our future industrial lubricant development will focus on durability and reliability control of either heavy-duty machine or manufacturing process equipment under severe operating conditions.

Industrial lubricants in the future will have to differ dramatically from those of today to meet the high-performance demand for future industrial machinery or manufacturing equipment. Energy efficiency and durability-controlled improvement will be critical for new components or process design. Further advancements of industrial lubricants will require more reliable and efficient methods of tribo-system evaluation. Foreseeably, the future will embrace the design and implementation of a “smart” tribo-system that will automatically control critical lubricant parameters, thereby optimizing lubricant and subsystem performance. These significant challenges to our automotive and petroleum industries will be seriously considered as the primary drivers for our ongoing research and development efforts. The end goal of this Special Issue is to provide current developments and future trends in industrial lubricants for industrial machinery and manufacturing equipment, while at the same time making significant gains in equipment safety, resource utilization, technology advancement, and environmental stewardship.

In addition, consumer demand for hybrid-electrical vehicles (HEV) and electrical vehicles (EV) has been increasing due to their benefits of high energy efficiency and lower emissions. The introduction of different components, materials, lubricant operating environments, and the demands on efficiency and durability necessitate making lubricant-additive technologies compatible with those advanced propulsion systems. Therefore, advanced lubrication technology is crucial in maintaining the high efficiency and reliability of HEV and EV vehicles. Original equipment manufacturers (OEMs) have requested the adoption of dedicated lubricants or driveline fluids to protect and ensure the smooth functioning of the electrified drivetrain parts. Transmission and driveline fluids tailored to hybrids and EVs must have the right electrical properties, ensure corrosion protection, and be compatible with insulating materials. They need to meet appropriate thermal cooling requirements, offer bearing protection, and provide oxidation and sludge control.

For this Special Issue, we invite high-quality papers that focus on, but are not limited to, the following topics: (Review papers are welcome as well as original papers).

  • Development of tribo-System for evaluation of industrial lubricant and advanced tribological material performance.
  • Tribochemistry for understanding tribological characteristics of industrial lubricants in their engineering applications.
  • Evaluation of advanced automotive lubricants or driveline fluids in hybrid electrified components using advanced tribo-systems for simulation.
  • Characterizing the industrial lubrication/tribological environments (such as shear, temperatures, loads, contaminants, etc.) operating in extreme environmental conditions.
  • Tribochemistry for understanding tribological characteristics of automotive lubricants in their advanced engineering applications.
  • Bench test evaluation and interpretation of the performance of automotive lubricant and thermal management systems.
  • Analysis of friction and wear performance in advanced powertrain or hybrid driveline electrification components.
  • Surface chemistry and mechanisms in industrial tribological systems.
  • Bench test evaluation and interpretation of industrial lubricant performance.
  • Analysis of friction and wear performance in industrial machinery or manufacturing equipment.
  • Analysis of tribochemical processes during tribo-system for industrial equipment and applications.
  • Friction induced tribochemical process in metallic and non-metallic systems.
  • Friction induced phase transformations and their role in wear.
  • Wear-resistant material development and tribo-testing.
  • Future trends for industrial machinery and manufacturing equipment.

Dr. Simon C. Tung
Prof. Dr. George Totten
Dr. Undrakh Mishigdorzhiyn
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Lubricants is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Industrial lubricants
  • Industrial and manufacturing machinery
  • Automotive lubricants
  • Tribo-systems
  • Driveline lubrication
  • Lubricant tribological performance testing
  • EV/hybrid vehicle applications

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Published Papers (13 papers)

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Editorial

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3 pages, 165 KiB  
Editorial
Advanced Industrial Lubricants and Future Development Trends of Tribo-Systems for Tribological Performance Evaluation
by Simon C. Tung, George Totten and Undrakh Mishigdorzhiyn
Lubricants 2023, 11(4), 167; https://doi.org/10.3390/lubricants11040167 - 7 Apr 2023
Viewed by 991
Abstract
It is possible to solve challenges in the global automotive and manufacturing industries by using a multidisciplinary approach to advanced industrial lubricants, their tribological performance evaluation, and new surface engineering techniques for prospective tribo-systems [...] Full article

Research

Jump to: Editorial

10 pages, 2252 KiB  
Article
Evaluation of Wear Resistance of AISI L6 and 5140 Steels after Surface Hardening with Boron and Copper
by Stepan Lysykh, Vasily Kornopoltsev, Undrakh Mishigdorzhiyn, Yuri Kharaev and Zhongliang Xie
Lubricants 2023, 11(2), 48; https://doi.org/10.3390/lubricants11020048 - 29 Jan 2023
Cited by 4 | Viewed by 1642
Abstract
(1) Background: Boriding is one of the most common methods of thermal-chemical treatment due to its excellent hardness and wear resistance of the produced diffusion layers. However, it has limited application compared to carburizing and nitriding because of fragility and chipping. Introducing another [...] Read more.
(1) Background: Boriding is one of the most common methods of thermal-chemical treatment due to its excellent hardness and wear resistance of the produced diffusion layers. However, it has limited application compared to carburizing and nitriding because of fragility and chipping. Introducing another alloying element into the boron media helps avoid those drawbacks and improve other surface properties of the layer. The purpose of this work is to improve the surface mechanical properties of L6 and 5140 low alloy steels by two-component surface hardening with boron and copper. (2) Methods: The treatment was performed by means of a powder-pack method using boron, copper, and aluminum powders in the following proportions: 60% B4C + 20% Al2O3 + 16% CuO + 4% NaF. The time–temperature parameters of the treatment were four hours exposure at 950 °C. Microstructure, elemental, and phase composition were investigated as well as microhardness and wear resistance of the obtained layers. (3) Results: Layers of up to 180–200 μm thick are formed on both steels as a result of treatment. Needle-like structures similar to pure boriding was obtained. The maximum microhardness was 2000 HV on L6 steel and 1800 HV on 5140 steel. These values correspond to iron borides and were confirmed by XRD analysis revealing FeB, Fe2B, and Cr5B3. The wear resistance of both steels was about ten times higher after the treatment compared to non-treated samples. (4) Conclusions: Surface hardening with boron and copper significantly improves the mechanical properties of both alloy steels. The results obtained are beneficial for different tribo-pair systems or three-body wear with abrasion and minimum impact loads. Full article
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11 pages, 1762 KiB  
Communication
Rheological and Tribological Study of Polyethylsiloxane with SiO2 Nanoparticles Additive
by Tuyana Dembelova, Badma Badmaev, Dagzama Makarova, Aleksandr Mashanov and Undrakh Mishigdorzhiyn
Lubricants 2023, 11(1), 9; https://doi.org/10.3390/lubricants11010009 - 26 Dec 2022
Cited by 5 | Viewed by 1977
Abstract
Nowadays, much attention is paid to the creation of high-performance lubricants with improved properties through the use of ultrafine nanopowders. The paper shows the results of studying the viscoelastic properties of samples of silicon dioxide nanoparticle suspensions based on polyethylsiloxane (silicone oil) by [...] Read more.
Nowadays, much attention is paid to the creation of high-performance lubricants with improved properties through the use of ultrafine nanopowders. The paper shows the results of studying the viscoelastic properties of samples of silicon dioxide nanoparticle suspensions based on polyethylsiloxane (silicone oil) by the acoustic resonance method. The method is based on a study of the additional coupling effect on the resonance characteristics of the piezoelectric resonator. The values of the shear modulus and the tangent of the mechanical loss angle were calculated. The interaction between polymer molecules and nanoparticles was characterized by infrared spectroscopy. The influence of silicon dioxide nanoparticles (as a nano-additive) on the performance characteristics of polyethylsiloxane lubricant is presented. The results of determining the friction coefficient from the sliding speed show an increase in the tear strength of the lubricating film, leading to improved tribological properties. Full article
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12 pages, 4082 KiB  
Article
Impact of Fatty Triamine on Friction Reduction Performance of MoDTC Lubrication Additive
by Camella Oumahi, Thierry Le Mogne, Antonio Aguilar-Tapia, Catherine Charrin, Christophe Geantet, Pavel Afanasiev, Benoit Thiebaut and Maria Isabel De Barros-Bouchet
Lubricants 2022, 10(12), 365; https://doi.org/10.3390/lubricants10120365 - 16 Dec 2022
Cited by 4 | Viewed by 1785
Abstract
The impact of a fatty triamine (Triameen YT) additive was investigated on the friction performance and stability of molybdenum dithiocarbamate (MoDTC) in the formulations containing polyalphaolefin synthetic base oil (PAO) and zinc dialkyldithiophosphate (ZDDP). Triamine has no significant effect when mixed with MoDTC [...] Read more.
The impact of a fatty triamine (Triameen YT) additive was investigated on the friction performance and stability of molybdenum dithiocarbamate (MoDTC) in the formulations containing polyalphaolefin synthetic base oil (PAO) and zinc dialkyldithiophosphate (ZDDP). Triamine has no significant effect when mixed with MoDTC and ZDDP, but it improves the performance of MoDTC alone. However, in the MoDTC—Triamine—PAO solutions, a chemical reaction easily occurred and a reddish precipitate was formed upon storage. According to IR, XPS, TEM, and XAS characterizations, this precipitate is poorly crystalline layered alkylammonium oxothiomolybdate. Formation of the precipitate impaired the tribological performance by decreasing the number of active species delivered at the sliding contact interface. However, low friction coefficients were recovered by redispersion of the precipitate in PAO. Full article
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16 pages, 2965 KiB  
Article
Assessing the High-Temperature Deposit Formation of Paraffinic and Naphthenic Oil Blends Using the Oil Chute Method
by Bettina Ronai, Christoph Schneidhofer, Franz Novotny-Farkas, Thomas Norrby, Jinxia Li, Jasmin Pichler and Marcella Frauscher
Lubricants 2022, 10(12), 327; https://doi.org/10.3390/lubricants10120327 - 23 Nov 2022
Cited by 1 | Viewed by 1771
Abstract
Due to the demand for higher efficiency, gas engine designs are changing in that gas engine oils are exposed to higher thermal stress and face challenges regarding the prevention of deposits. In this work, the “oil chute” laboratory test was used to study [...] Read more.
Due to the demand for higher efficiency, gas engine designs are changing in that gas engine oils are exposed to higher thermal stress and face challenges regarding the prevention of deposits. In this work, the “oil chute” laboratory test was used to study the high-temperature deposit-formation tendency of various paraffinic and naphthenic base oil blends. The oil chute is a setup that circulates oil through two different temperature zones, the hot zone being a heated metal chute that triggers deposit formation. In addition, the thermo-oxidative stability of the oil blends was investigated using an artificial alteration method. The results showed that naphthenic base oils have the capability of substantially reducing high-temperature deposit formation. However, they tend to degrade faster under thermo-oxidative stress. Therefore, finding the right balance between paraffinic and naphthenic base oil components will allow the formulation of gas engine oils that provide the right properties to cope with the higher stress levels they are subjected to in modern gas engines. Full article
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16 pages, 3291 KiB  
Article
Implementation of Nitration Processes in Artificial Ageing for Closer-to-Reality Simulation of Engine Oil Degradation
by Charlotte Besser, Adam Agocs, Andjelka Ristic and Marcella Frauscher
Lubricants 2022, 10(11), 298; https://doi.org/10.3390/lubricants10110298 - 5 Nov 2022
Cited by 6 | Viewed by 1826
Abstract
During their service, engine oils suffer from various influencing parameters such as thermo-oxidative stress and nitration, hence, the accumulation of degradation products and the entry of contaminants. Accordingly, ICEs need to be able to operate satisfactorily, especially with a degraded lubricant, making it [...] Read more.
During their service, engine oils suffer from various influencing parameters such as thermo-oxidative stress and nitration, hence, the accumulation of degradation products and the entry of contaminants. Accordingly, ICEs need to be able to operate satisfactorily, especially with a degraded lubricant, making it highly recommendable to use such oils for component testing in ICE development. Thus, a new nitrative thermo-oxidative ageing method is presented for closer-to-reality simulation of engine oil alteration with the intention to provide reproducibly aged oils for subsequent bench testing. With this method, a target used oil from field application was replicated and the comparability of oil condition in the lab vs. field regarding oxidation, nitration, additive depletion, and acidification amongst others was verified by conventional and advanced analyses. Special focus was laid on the identification of nitration products, proving them to be predominantly oxidized aromatic species or organophosphates. The presented method gives valuable benefit for the closer-to-reality ageing of engine oils in reasonable time frames with moderate costs and, hence, for the provision of test oils for ICE bench testing enabling rapid engine component assessment. Full article
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20 pages, 7715 KiB  
Article
Monitoring the Conditions of Hydraulic Oil with Integrated Oil Sensors in Construction Equipment
by Sung-Ho Hong and Hong-Gyu Jeon
Lubricants 2022, 10(11), 278; https://doi.org/10.3390/lubricants10110278 - 25 Oct 2022
Cited by 8 | Viewed by 2894
Abstract
Maintenance and reliability are crucial aspects for operating construction equipment in harsh environmental conditions. One of the methods used to improve the maintenance and reliability of construction equipment is oil diagnosis. In this study, monitoring of conditions was performed through the use of [...] Read more.
Maintenance and reliability are crucial aspects for operating construction equipment in harsh environmental conditions. One of the methods used to improve the maintenance and reliability of construction equipment is oil diagnosis. In this study, monitoring of conditions was performed through the use of an integrated oil sensor for hydraulic oil in construction equipment. Hydraulic oil in construction equipment is polluted by various materials such as moisture and dust. Therefore, the present work investigated the change in the state of hydraulic oil caused by the presence of major pollutants in construction equipment. The degree of contamination of the hydraulic oil was evaluated using an integrated oil sensor that could measure absolute viscosity, density, temperature and dielectric constant. It is difficult to determine the influence of each pollutant source on hydraulic oil. Therefore, a simple experimental device and diagnostic program were constructed to effectively measure variations in the properties of hydraulic oil caused by each contaminant source. In particular, the focus was on the dielectric constant and examination of its usefulness. In addition to testing various contaminant conditions in the laboratory, varnish-contaminated lubricants used in actual construction equipment were verified. The results showed little change in the dielectric constant when introducing dust and improper lubricants. However, the dielectric constant was affected by the incorporation of water and the generation of varnish, which led to evident variations. In particular, a direct correlation was found between varnish contamination and the dielectric constant measured by the oil sensor, and the cause was explained based on the results of elemental component analysis. Therefore, measuring absolute viscosity, density, and temperature when monitoring the condition of hydraulic oil in construction equipment can provide useful information regarding lubricant and machine condition; however, the dielectric constant is most useful in detecting moisture incorporation and varnish contamination caused by oil deterioration. Full article
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9 pages, 2103 KiB  
Article
Oil Change Interval Evaluation of Gearbox Used in Heavy-Duty Truck E-Axle with Oil Analysis Data
by Shufa Yan, Zhuo Kong, Hongwei Liu, Bin Li, Mao Fan and Xiaokun Zhang
Lubricants 2022, 10(10), 252; https://doi.org/10.3390/lubricants10100252 - 11 Oct 2022
Cited by 4 | Viewed by 1871
Abstract
Regular lubricating oil change in the gearbox is desirable for improving vehicle reliability and reducing operating costs. To achieve this objective, evaluating the oil change interval is necessary. However, due to the complex and dynamic properties of oil degradation, oil change interval evaluation [...] Read more.
Regular lubricating oil change in the gearbox is desirable for improving vehicle reliability and reducing operating costs. To achieve this objective, evaluating the oil change interval is necessary. However, due to the complex and dynamic properties of oil degradation, oil change interval evaluation has been a bottleneck in practice. Therefore, a solution strategy is proposed in this paper that utilizes the oil physicochemical properties derived from oil analysis data to determine the optimal oil change interval. With a large amount of oil analysis data collected, the iron (Fe) debris, kinematic viscosity (100 °C), and total acid number (TAN) are considered to be the oil change indicators of lubricating oil. By monitoring the changes in the selected oil change indicators, linear regression is firstly applied to the original oil analysis data to reveal the dynamic degradation process. Then, the Wiener-based stochastic process is used to describe the first hitting time and the increasing trends of the selected oil change indicator. Finally, the oil change interval can be obtained under the concept of the first hitting time. Compared with the planned maintenance time, the proposed method seems reasonable considering the dynamic property of oil degradation. The effectiveness of the proposed method is evaluated using a case study with an oil analysis dataset from an E-axle with a two-shift gearbox. The results show that the oil change interval increased by approximately 10,000 km (50%) compared with the planned maintenance interval. This will reduce vehicle maintenance time and save maintenance costs. Full article
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12 pages, 1259 KiB  
Article
Nanopowders of Different Chemical Composition Added to Industrial Lubricants and Their Impact on Wear Resistance of Steel Friction Pairs
by Valerii Kosarchuk, Mykola Chausov, Andrii Pylypenko, Volodymyr Tverdomed, Pavlo Maruschak and Abdellah Menou
Lubricants 2022, 10(10), 244; https://doi.org/10.3390/lubricants10100244 - 29 Sep 2022
Cited by 3 | Viewed by 1592
Abstract
The authors have previously proposed and tested a method for increasing the wear resistance of heavy-loaded friction pairs by saturating industrial lubricants with the metallic nanopowder of the friction pair’s component that has a lower hardness. To confirm the effectiveness of this concept, [...] Read more.
The authors have previously proposed and tested a method for increasing the wear resistance of heavy-loaded friction pairs by saturating industrial lubricants with the metallic nanopowder of the friction pair’s component that has a lower hardness. To confirm the effectiveness of this concept, this paper presents the results of experimental investigations into the tribological characteristics of two medium carbon steels (rail steel K74 and structural steel 20) during sliding friction. Friction surfaces lubricated with compositions based on the Bio Rail industrial lubricant were saturated with nanopowder additives of copper, carbon, and magnesium alloy, as well as K74 and 20 steels. The research findings indicate that lubricants saturated with nanomaterials of K74 and 20 steels help achieve the highest wear resistance, as compared to lubricants based on pure grease and lubricating compositions based on copper, magnesium alloy and carbon powders. The test results confirmed that the mean friction coefficient of the rail steel remained at the level of 0.25 for three hours of operation, which is optimal for the “wheel–rail” friction pair. The proposed method of manufacturing lubricating compositions can be used to improve the efficiency of lubrication of railway rails and rolling stock wheels. Full article
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17 pages, 5284 KiB  
Article
Microstructure and Wear Resistance of Hot-Work Tool Steels after Electron Beam Surface Alloying with B4C and Al
by Undrakh Mishigdorzhiyn, Aleksandr Semenov, Nikolay Ulakhanov, Aleksandr Milonov, Dorzho Dasheev and Pavel Gulyashinov
Lubricants 2022, 10(5), 90; https://doi.org/10.3390/lubricants10050090 - 7 May 2022
Cited by 6 | Viewed by 2088
Abstract
(1) Background: Operational properties and durability of dies in different metal-forming processes significantly depend on their surface quality. Major die failures are related to surface damage due to heat checking cracks, wear, etc. Thereby, strengthening of the working surfaces of dies for hot [...] Read more.
(1) Background: Operational properties and durability of dies in different metal-forming processes significantly depend on their surface quality. Major die failures are related to surface damage due to heat checking cracks, wear, etc. Thereby, strengthening of the working surfaces of dies for hot bending, stamping, forging, and die casting processes is an urgent engineering challenge. Surface alloying with high-energy beams improves the properties of steel products. In these processes, the alloying powders and the treated surfaces can be remelted by electron beam within a short time while the bulk structure of the component remains unchanged, resulting in minimal distortion. The paper presents the results of the electron beam surface alloying (EBSA) of H21 and L6 tool steels with the treatment pastes containing boron carbide and aluminum powders. (2) Methods: Two types of pastes were used for surface alloying: a single-component (B4C) paste and a two-component (B4C+Al) one. The microstructure, microhardness, wear resistance, and elemental and phase composition of the layers obtained on steels were investigated. (3) Results: Four layers up to 0.4 mm thick were distinguished on the surface of the steels after the EBSA. Metallographic analysis showed coarse dendrite formation in the layers embedded in matrices of a eutectic or a solid solution. Microhardness of the steels after the two-component EBSA was higher than after B4C EBSA, which was related to a higher concentration of hard phases, such as iron borides and carbides. In addition, aluminum boride was revealed by the XRD analysis on L6 steel after B4C+Al EBSA. (4) Conclusions: Wear test indicated that the most resistant samples were H21 steel after single B4C EBSA and L6 steel after B4C+Al EBSA. Both samples contained carbon particles in the layer contributing to the high wear resistance as a lubricant. The conducted research is beneficial for mechanical engineering, automotive engineering, medical technology, aerospace engineering, and related industries, where coatings with high microhardness, wear resistance, and surface quality are demanded. Full article
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11 pages, 2310 KiB  
Article
Tribocorrosion Influenced Pitting of a Duplex Stainless Steel
by Peter Renner, Yan Chen, Zhihao Huang, Ajinkya Raut and Hong Liang
Lubricants 2021, 9(5), 52; https://doi.org/10.3390/lubricants9050052 - 7 May 2021
Cited by 12 | Viewed by 2912
Abstract
Due to its accelerated, uncontrollable, and unpredictable nature, pitting is one of the most common failure modes in pipelines used for oil and gas exploration. A comprehensive understanding of the mechanisms of pitting under conditions involving both abrasion and corrosion is currently lacking. [...] Read more.
Due to its accelerated, uncontrollable, and unpredictable nature, pitting is one of the most common failure modes in pipelines used for oil and gas exploration. A comprehensive understanding of the mechanisms of pitting under conditions involving both abrasion and corrosion is currently lacking. This research investigated the effects of mechanical rubbing on the development of pitting of a widely used Type 2205 duplex stainless steel. Tribocorrosion experiments were conducted under mildly abrasive conditions where there is pitting but no significant material loss. Results showed that passivation was accelerated by rubbing, even though pitting was simultaneously formed. The length-to-width aspect ratio of the pits increased exponentially when the normal load during corrosive wear tests was increased. This phenomenon could lead to catastrophic failure in industrial applications such as underground and deep ocean pipes in the oil and gas industry. Full article
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13 pages, 4455 KiB  
Article
Novel Uses of Al2O3/Mos2 Hybrid Nanofluid in MQCL Hard Milling of Hardox 500 Steel
by Tran Minh Duc, Tran The Long and Ngo Minh Tuan
Lubricants 2021, 9(4), 45; https://doi.org/10.3390/lubricants9040045 - 16 Apr 2021
Cited by 17 | Viewed by 2741
Abstract
In recent years, the application of environmentally friendly cutting fluids in the metal cutting industry has been a growing concern in all over the world. In this study, the minimum quantity cooling lubrication (MQCL) technique, which uses very small amount of cutting oil, [...] Read more.
In recent years, the application of environmentally friendly cutting fluids in the metal cutting industry has been a growing concern in all over the world. In this study, the minimum quantity cooling lubrication (MQCL) technique, which uses very small amount of cutting oil, is motivated to apply to the hard milling process of Hardox 500 steel. Further, rice bran oil, a natural biodegradable oil, is used as the base fluid of Al2O3/MoS2 hybrid nanofluid. ANOVA analysis is used to study the influences of nanoparticle concentration, cutting speed, and feed rate on surface roughness. The obtained results indicate that good surface quality is achieved and the cutting speed is significantly increased to 140 m/min (about 2.55–2.80 times higher than the recommended values) due to the better cooling and lubricating effects from MQCL system and Al2O3/MoS2 hybrid nanofluid. Moreover, the microstructure of the machined surface proves the formation of MoS2 tribo film by using Al2O3/MoS2 hybrid nanofluid, indicating that the effectiveness of each type of nanoparticle in hybrid nanofluid has been promoted. Furthermore, the important technical guides for machining Hardox 500 steel are provided. Full article
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21 pages, 22558 KiB  
Article
Synthesis and Morphological Characterization of Electroless-Deposited Ni-P Coatings on Diamond Abrasives
by Lian Ma, Yan Chen, Peter Renner, Dilworth Parkinson, Alex Fang and Hong Liang
Lubricants 2021, 9(2), 20; https://doi.org/10.3390/lubricants9020020 - 20 Feb 2021
Cited by 12 | Viewed by 3249
Abstract
Deposition of a coating on rough surfaces faces unique challenges due to the complexity of substrate morphology. In the present research, electroless deposition of a Ni-P coating was successfully deposited on diamond particles. Microtomography was conducted to study the deposition mechanisms. It revealed [...] Read more.
Deposition of a coating on rough surfaces faces unique challenges due to the complexity of substrate morphology. In the present research, electroless deposition of a Ni-P coating was successfully deposited on diamond particles. Microtomography was conducted to study the deposition mechanisms. It revealed that the coating coverage rate on diamond particles was affected by the synergistic action of the deposition time, substrate morphology, and hypophosphite concentration. The best coverage was achieved in a solution with 0.2 mol/L hypophosphite. Two major morphological features of the coating: nodular and smooth, were influenced by the deposition parameters, coating integrity, and substrate morphology. The failure was seen in fractured and peeled off coatings. It was due to residual stress produced by the coalescing of crystallites during the deposition. This failure mechanism explains the tendency of coating fracture at three morphological features of the substrate. This work is beneficial to semiconductor manufacturing where effective cutting in chip fabrication is essential. Full article
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