{"title":"Additive Formulation for Reducing Noise in Chain CVTs","authors":"Toshiaki Iwai, Ken Nakano","doi":"10.2474/trol.18.313","DOIUrl":"https://doi.org/10.2474/trol.18.313","url":null,"abstract":"","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"173 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135927760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Contact Mechanics of an Unstable Viscoelastic Medium with Retardation as a Model for Mechanical Activation and Synchronization of Cardiac Spheroids","authors":"Valentin L. Popov, Ken Nakano","doi":"10.2474/trol.18.319","DOIUrl":"https://doi.org/10.2474/trol.18.319","url":null,"abstract":"","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"5 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135927914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lubricants are used to reduce friction and wear in machines, saving billions of dollars worldwide in energy and breakdown costs and lowering CO2 emissions. Today, most lubricants are made using hydrocarbons derived from crude oil, which is a finite resource, although alternative bio-based lubricants are also being investigated, as is the re-refining of used lubricants to make new base oil. The machines. It is also shown that an effective way to make lubricants more sustainable is to extend lubricant oil drain intervals and collect used oil and re-refine it to make base oil for re-use. The role of bio-based lubricants, and their benefits and disadvantages are discussed. Other aspects in which lubricants can be made more sustainable are also briefly covered, such as lubricant packaging, the removal of toxic additives via improved regulatory chemistry, and the use of renewable electricity in blending plants.
{"title":"A Closer Look at Sustainable Lubricants","authors":"Robert Ian Taylor","doi":"10.2474/trol.18.268","DOIUrl":"https://doi.org/10.2474/trol.18.268","url":null,"abstract":"Lubricants are used to reduce friction and wear in machines, saving billions of dollars worldwide in energy and breakdown costs and lowering CO2 emissions. Today, most lubricants are made using hydrocarbons derived from crude oil, which is a finite resource, although alternative bio-based lubricants are also being investigated, as is the re-refining of used lubricants to make new base oil. The machines. It is also shown that an effective way to make lubricants more sustainable is to extend lubricant oil drain intervals and collect used oil and re-refine it to make base oil for re-use. The role of bio-based lubricants, and their benefits and disadvantages are discussed. Other aspects in which lubricants can be made more sustainable are also briefly covered, such as lubricant packaging, the removal of toxic additives via improved regulatory chemistry, and the use of renewable electricity in blending plants.","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"37 S1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135809045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mostafa El Laithy, Ling Wang, Terry J. Harvey, Bernd Vierneusel
The development of subsurface microstructural alterations known as dark etching regions (DERs) and white etching bands (WEBs) in rolling element bearings due to rolling contact fatigue have been investigated for the past eight decades, focusing on their initiation and formation mechanisms. They have only recently been shown to be driven by repetitive cycles of energy build-up due to micro-plastic deformation and energy release through recrystallization and recovery, which results in the formation of equiaxed and elongated ferrite grains, as well as lenticular carbides. These features develop within the bearing subsurface from DER to WEBs during bearing operation at moderate to high loads, but little evidence has been presented in the literature to understand links between DER and WEBs and the nucleation and growth of subsurface cracks. This investigation examines WEBs, including low angle bands (LABs) and high angle bands (HABs), in detail especially focusing on their late stages to understand such links. A number of techniques, including optical microscopy, scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) have been used to examine the features involved. Analysis on WEBs obtained through serial sectioning has revealed that voids initiating at the interface between lenticular carbides and equiaxed ferrite grain bands within WEBs have led to crack formation which can subsequently propagate to bearing surfaces. Interactions between WEBs and non-metallic inclusions (NMIs) are observed to lead to de-bonding of inclusions from their surrounding microstructure and void formation, which has also found to influence the integrity of the bearings at late stages. Alumina and Manganese sulphide (MnS) inclusions are the mostly observed NMIs that de-bond and develop microcracks when interacting with WEBs. These findings thus provide important insights into the link between inclusions and crack initiation and represent a further step towards a fundamental understanding of the rolling contact fatigue process.
{"title":"Influence of White Etching Bands Formation on Integrity of Rolling Element Bearings","authors":"Mostafa El Laithy, Ling Wang, Terry J. Harvey, Bernd Vierneusel","doi":"10.2474/trol.18.373","DOIUrl":"https://doi.org/10.2474/trol.18.373","url":null,"abstract":"The development of subsurface microstructural alterations known as dark etching regions (DERs) and white etching bands (WEBs) in rolling element bearings due to rolling contact fatigue have been investigated for the past eight decades, focusing on their initiation and formation mechanisms. They have only recently been shown to be driven by repetitive cycles of energy build-up due to micro-plastic deformation and energy release through recrystallization and recovery, which results in the formation of equiaxed and elongated ferrite grains, as well as lenticular carbides. These features develop within the bearing subsurface from DER to WEBs during bearing operation at moderate to high loads, but little evidence has been presented in the literature to understand links between DER and WEBs and the nucleation and growth of subsurface cracks. This investigation examines WEBs, including low angle bands (LABs) and high angle bands (HABs), in detail especially focusing on their late stages to understand such links. A number of techniques, including optical microscopy, scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) have been used to examine the features involved. Analysis on WEBs obtained through serial sectioning has revealed that voids initiating at the interface between lenticular carbides and equiaxed ferrite grain bands within WEBs have led to crack formation which can subsequently propagate to bearing surfaces. Interactions between WEBs and non-metallic inclusions (NMIs) are observed to lead to de-bonding of inclusions from their surrounding microstructure and void formation, which has also found to influence the integrity of the bearings at late stages. Alumina and Manganese sulphide (MnS) inclusions are the mostly observed NMIs that de-bond and develop microcracks when interacting with WEBs. These findings thus provide important insights into the link between inclusions and crack initiation and represent a further step towards a fundamental understanding of the rolling contact fatigue process.","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"236 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135809050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Minimum quantity lubrication (MQL) has performed optimum lubrication but poor cooling during turning process. Thus, hybrid nanocooling-lubricants for minimum quantity cooling-lubrication to achieve sufficient lubrication and cooling effect for high speed turning titanium alloy (Ti6Al4V) material. This study is targeted on the machinability performance of G-Al 2 O 3 hybrid nanocooling-lubricants MQCL and conventional fluids cooling condition with variable cutting speeds at constant feed rate as input parameters to evaluate the machining temperature and cutting insert flank wear as quality responses. Scanning electron microscopy-energy dispersive X-ray (SEM-EDX) analysis was implemented to determine Ti6Al4V workpiece chemical elemental deposition on the cutting insert flank surface. Experimental results obtained that significantly increased of machining temperature from 206°C to 317°C based on type-K thermocouple wire measurement as the increment of cutting speeds from 120 m/min to 180 m/min. However, machining temperature decreased with the increasing of lubrication flow rate of MQCL 10 mL/min to 40 mL/min, then to the conventional fluids cooling condition. The comparison to conventional fluids cooling condition, the G-Al 2 O 3 hybrid nanocooling-lubricants MQCL at the cutting speed of 120 m/min significantly increased tool life for 51% and cutting speed of 180 m/min for 28%, respectively. Furthermore, SEM-EDX has presented that titanium element deposited on cutting insert flank surface, which has shown micro-attrition, abrasion and adhesion wear leading edge chipping or fracture are identified as the main tool wear mechanisms.
{"title":"Effects of Hybrid Nanocooling-Lubricants MQCL on Machining Temperature and Tool Wear Mechanisms under Turning Process of Titanium Alloy","authors":"Lim Syh Kai, Ahmad Razlan Yusoff","doi":"10.2474/trol.18.385","DOIUrl":"https://doi.org/10.2474/trol.18.385","url":null,"abstract":"Minimum quantity lubrication (MQL) has performed optimum lubrication but poor cooling during turning process. Thus, hybrid nanocooling-lubricants for minimum quantity cooling-lubrication to achieve sufficient lubrication and cooling effect for high speed turning titanium alloy (Ti6Al4V) material. This study is targeted on the machinability performance of G-Al 2 O 3 hybrid nanocooling-lubricants MQCL and conventional fluids cooling condition with variable cutting speeds at constant feed rate as input parameters to evaluate the machining temperature and cutting insert flank wear as quality responses. Scanning electron microscopy-energy dispersive X-ray (SEM-EDX) analysis was implemented to determine Ti6Al4V workpiece chemical elemental deposition on the cutting insert flank surface. Experimental results obtained that significantly increased of machining temperature from 206°C to 317°C based on type-K thermocouple wire measurement as the increment of cutting speeds from 120 m/min to 180 m/min. However, machining temperature decreased with the increasing of lubrication flow rate of MQCL 10 mL/min to 40 mL/min, then to the conventional fluids cooling condition. The comparison to conventional fluids cooling condition, the G-Al 2 O 3 hybrid nanocooling-lubricants MQCL at the cutting speed of 120 m/min significantly increased tool life for 51% and cutting speed of 180 m/min for 28%, respectively. Furthermore, SEM-EDX has presented that titanium element deposited on cutting insert flank surface, which has shown micro-attrition, abrasion and adhesion wear leading edge chipping or fracture are identified as the main tool wear mechanisms.","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"4 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135927927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of adsorbed water layers in sliding phenomena has been widely recognized, but it has yet to be explained thoroughly after many years of research. Previous researches tend to explain the phenomena from chemical and qualitative viewpoints, thus physical viewpoint approaches with quantitative evidence are necessary to complement the previous research works. Studies were done to estimate the thickness of adsorbed water layers in recent years to obtain quantitative evidence of the effect of adsorbed water layers. It was found that the thickness of the adsorbed water layer derived from atmospheric humidity could provide physical influences on sliding phenomena. The hypothesis in this study based on the Stribeck curve is; the friction coefficient may decrease significantly with the increase of sliding speed at high relative humidity (RH) compared to low RH. To verify the hypothesis, a pair of JIS SUS304 austenitic stainless steel balls were scratched against each other horizontally with a vertical overlapping distance of 80 µm at sliding speeds of 20, 200, and 2000 µm·s−1 in RH of 5, 55, and 95%. The experimental results supported the hypothesis as the friction coefficient for medium to high RH decreased significantly with increasing sliding speed while the friction coefficient decreases slightly at low RH. The friction coefficient decreases significantly at high sliding speed and RH. The possible physical effects of the adsorbed water layers were suggested.
{"title":"Influences of Atmospheric Humidity on Sliding Speed Characteristics of Dry Sliding Phenomena","authors":"Wei Chee Hong, Kanao Fukuda, Shahira Liza","doi":"10.2474/trol.18.339","DOIUrl":"https://doi.org/10.2474/trol.18.339","url":null,"abstract":"The effect of adsorbed water layers in sliding phenomena has been widely recognized, but it has yet to be explained thoroughly after many years of research. Previous researches tend to explain the phenomena from chemical and qualitative viewpoints, thus physical viewpoint approaches with quantitative evidence are necessary to complement the previous research works. Studies were done to estimate the thickness of adsorbed water layers in recent years to obtain quantitative evidence of the effect of adsorbed water layers. It was found that the thickness of the adsorbed water layer derived from atmospheric humidity could provide physical influences on sliding phenomena. The hypothesis in this study based on the Stribeck curve is; the friction coefficient may decrease significantly with the increase of sliding speed at high relative humidity (RH) compared to low RH. To verify the hypothesis, a pair of JIS SUS304 austenitic stainless steel balls were scratched against each other horizontally with a vertical overlapping distance of 80 µm at sliding speeds of 20, 200, and 2000 µm·s−1 in RH of 5, 55, and 95%. The experimental results supported the hypothesis as the friction coefficient for medium to high RH decreased significantly with increasing sliding speed while the friction coefficient decreases slightly at low RH. The friction coefficient decreases significantly at high sliding speed and RH. The possible physical effects of the adsorbed water layers were suggested.","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"236 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135809048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Motoyuki Murashima, Kazuma Aono, Noritsugu Umehara, Takayuki Tokoroyama, Woo-Young Lee
{"title":"Active control of Lubricant Flow Using Dielectrophoresis and Its Effect on Friction Reduction","authors":"Motoyuki Murashima, Kazuma Aono, Noritsugu Umehara, Takayuki Tokoroyama, Woo-Young Lee","doi":"10.2474/trol.18.292","DOIUrl":"https://doi.org/10.2474/trol.18.292","url":null,"abstract":"","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135872064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Surface Life Modelling of Tribological Components – From Surface Roughness to Bearings and Gear Life","authors":"Guillermo Enrique Morales-Espejel","doi":"10.2474/trol.18.255","DOIUrl":"https://doi.org/10.2474/trol.18.255","url":null,"abstract":"","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135872071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guillermo Enrique Morales-Espejel, Armando Félix-Quiñonez, Hugo Boffy
{"title":"Stress Based Model for General Rolling Contact with Surface and Subsurface Survival: Application to Gears with Material Inhomogeneities","authors":"Guillermo Enrique Morales-Espejel, Armando Félix-Quiñonez, Hugo Boffy","doi":"10.2474/trol.18.280","DOIUrl":"https://doi.org/10.2474/trol.18.280","url":null,"abstract":"","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135928488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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