Electric machines are widely used in for instance the automotive industry in electric vehicles and in wind turbines. The electrical machines have mechanical bearings as an integral part used to transmit power and load. In addition, the main function includes reducing friction between interacting surfaces. However, it is one of the most failing machine elements in these machines. To improve operational sustainability and reduce maintenance costs, understanding bearing failure mechanisms under electrical influence is important. One of the main reasons of bearing failure is linked to high frequency power switches typically used to enhance electric machines’ efficiency. The increase in switching rate induces more frequent common mode voltage fluctuations making the system vulnerable to bearing currents. A small voltage difference of a few ten volts can induce significant electric stress on the bearing depending on the lubricant film thickness and related tribological parameters. The electric charge build-up leads to electric current conduction (arc discharge which happens when the voltage exceeds the breakdown voltage) ultimately damaging the bearing. There are different mitigation strategies which are used to restrict bearing currents through grounding or using completely insulative bearings such as ceramic ones. However, at the moment, there are no satisfactory solutions and there is a need for efficient and economical solutions to the problem. On the other hand, various filters are used to reduce the amplitude and its frequency of bearing currents, but they only partly solve the problem. Similarly, the insulative surface coatings provides high electrical resistance but start acting as capacitors. At a sufficiently high voltage difference, the current passes through the system. Therefore, mitigation strategies are still being explored to improve system performance and service-life. To understand the bearing discharge activity and electrical breakdowns, an electrified ball bearing rig is developed with the ability of testing different electrical properties of lubricants and running conditions. To be able to characterize the electrical properties of a bearing, two electrical circuits are designed. Experimental tests are carried out with PAO-15 and an electrical conductivity-enhanced PAO-15/P-SiSO lubricant with addition of ionic liquids. The influence of different tribological parameters such as rotational speed and viscosity are compared with respect to discharge activity. In addition, two fully formulated experimental oils are compared and evaluated in terms of their electrical performance. The bearing is found to be in different states showing electric-field dependent insulation breakdown ranging from resistive to resistive-capacitive to capacitive states. The electric characterization shows a difference between the boundary, mixed and full film lubrication regimes. Conclusively, the electrical behavior of a mechanical bearing is characterized experimentally to understand discharge problem and roadmap solution opportunities.

Obtaining an enhanced lifespan for mechanical transmissions has become a challenge in diverse application sectors. Micropitting as a contact fatigue mechanism has seriously jeopardized the well-being of rolling-sliding elements present for instance in gearboxes. Additivation through copper nanoadditives has demonstrated promising results in preventing contact fatigue. There is a need to assess the influence of copper nanoadditives on micropitting and mild wear before contemplating employing them in real transmission gearboxes. Consequently, this research work aims to acquire knowledge of the tribological behavior of rolling-sliding contacts additivated with a copper nanoadditive, emphasizing the influence of two different copper nanoadditive concentrations (0.3% and 3%) on wear and micropitting as failure mechanisms. Tests were performed using a micropitting test rig. Micropitting and wear were analyzed at different slide-to-roll ratios (1%, 5%, and 30%), different load conditions (1.5 GPa and 2.5 GPa), and different temperatures (60 °C and 100 °C), for all versions of the studied lubricant. There was no change in friction behavior between the versions of the oil additivated with the copper nanoadditive and its original version. Furthermore, it was found a reduction of micropitting for the 3% version of the studied oil in some operating conditions, and a reduction of the average wear volume for this same concentration in all studied operating conditions. On the other hand, it was found that the 0.3% version of the studied oil promoted wear with an increasing slide-to-roll ratio when compared with the original version of the studied oil. A higher reduction in wear was obtained for the 0.3% version of the studied oil with an increasing temperature when compared with the 3% version. These results indicate that copper nanoadditives exhibit the potential to reduce micropitting in non-conformal rolling-sliding contacts typically found in gears and rolling-element bearings.

The objective of this thesis work was to develop a method to detect early damage on small planetary gear sets that are installed in Atlas Copco nutrunners. The project has gone through several stages of product development, from idea to working product and signal analysis. Currently, Atlas Copco have a test rig for testing these planetary gears, this rig has been proven to be insufficient at detecting faults during an ongoing test. A new tailored test rig was therefore designed and manufactured. Low noise and low amount of vibration was of interest when designing the rig. Four concepts was thought of and evaluated through simulations using Matlab and Simulink. Most of the components of the rig were manufactured in the workshop at Atlas Copco in Nacka. Methods fo rmeasuring torsional, transverse and acoustic vibration was implemented and analyzed. There are many different parameters considering fault of fixed shaft gears. However, these are not easily applicable on a planetary gear because of the nature of its design. Therefore, special techniques are required. Two “new” parameters were tested (NSDS,FRMS [Lei. et al.]) with positive results. Pitting of individual gear members could befound.

No description available.

High heat in mechanical seals is a long-recognized main failure cause, disrupting the seal's vital lubricating film and heating temperature-sensitive process media. A way to accommodate the seal's heat generation is by choosing materials with high thermal conductivity, such as silicon carbide (SiC). In single-use and short operating time applications, the usage of SiC may be greatly over-dimensioned, unnecessarily environmentally intense, and expensive. There is a desire to apply other materials for these cases, but the heat generation of the mechanical seal poses great limitations in material selections.  The purpose of this study is to reduce the operating temperature of mechanical seals to enable the application of cheaper and more sustainable materials. The seals used for testing are presently used in Alfa Laval’s single-use separators, CultureOne, and accompanying this work is the designing of a temperature measuring rig for the specific mechanical seal to be tested in its applied environment. The following research questions have been formulated to concretize the presented problematization:     RQ1: Which parameters have the highest significance for generated heat in the single-use mechanical seal?   RQ2: How can the heat of the mechanical seal’s wear face be measured while operating in the CultureOne machine?    This study is deductive, intending to gather quantitative data through thermal measuring. The temperature measuring rig was designed with inspiration from previous similar studies and was then validated through repeated testing and comparisons with FEM-simulations of the tested case. This resulted in a detected temperature loss of 1°C, which has been accounted for in the conclusions. During validation tests, a standard original seal temperature to use as a comparison was found to be 41°C.    Heat-affecting parameters have been gathered and tested through the method of Design of Experiments (DoE), where a Placket-Burman design was chosen to enable testing 9 parameters with 12 tests. The results of the study indicate that surface roughness and sealing liquid temperature have significant effects on the seal temperature. Roughening the surface of the mechanical seal’s polished, static carbon face, as achieved with a 1000-grit abrasive paper, provided a heat mitigating effect of -9.3 °C, which is a 23% heat reduction. Similarly, introducing more cooling power to the system by cooling the sealing liquid with external methods such as an ice bath provided a heat-reducing effect of -5.4 °C at the end of a one-hour test, reducing the temperature with 13%. Combining the parameters provided a 36% reduction in heat for a one-hour run with the mechanical seal in the CultureOne Primo machine. Thus, the temperature-reducing strategies discovered in this study can be applied to enable more sustainable and cheaper material selections for mechanical face seals. / Hög temperatur i plantätningar är sedan länge uppmärksammat som en huvudsaklig haveriorsak eftersom det i många fall leder till att den smörjande vätskefilmen störs. En åtgärd för att avlägsna tätningens värme är att välja material med hög värmeledningsförmåga, som exempelvis kiselkarbid. Vid engångsapplikationer och andra tillämpningsområden med kort tid i användning har kiselkarbidtätningar ofta en överdimensionerad livslängd samtidigt som materialet är både miljöpåfrestande och dyrt i jämförelse med andra material. Således finns behovet att byta material hos tätningar i dessa applikationer, men värmegenereringen utgör hinder och begränsar alternativen i materialvalet.    Målet med denna studie är att sänka temperaturen hos mekaniska plantätningar för att möjliggöra val av billigare och miljövänligare material. Tätningarna som används för studiens experiment sitter i Alfa Lavals engångsseparator, CultureOne. Till denna studie hör framtagandet av en metod och testuppställning för att mäta temperaturen hos dessa tätningar under drift i sin tillämpade miljö. Utifrån problematiken har följande forskningsfrågor formulerats:    FF1: Vilka parametrar har störst signifikans för värmegenerering i engångstätningarna?    FF2: Hur kan temperaturen av plantätningarnas nötningsyta mätas under drift i CultureOne-maskinen?   Studien är av deduktiv natur, med insamling av primärt kvantitativa data genom temperaturmätningar. Metoden för temperaturmätning togs fram med stöd i mätmetoder från andra studier på tätningar, och mätvärdenas riktighet validerades genom kalibreringssteg, tester och jämförelser med FEM-simuleringar av tätningen. Under kalibreringen detekterades en värmeförlust på 1°C mellan uppmätt temperatur och sann temperatur av tätningens nötningsyta, vilket kompenseras för i slutsatserna. Under normala körförhållanden mättes tätningens temperatur till 41°C vilket användes som utgångspunkt att jämföra med senare experiment.    Värmegenererande parametrar för tätningar har sammanställts och testats genom en statistisk försöksplanering, där en Placket-Burman-design implementerades. Resultaten visar att ytfinhet och temperatur av tätningsvätska har signifikanta effekter för tätningens temperatur. Genom att skapa en grövre yta för plantätningens statiska halvas nötningsyta, som uppnått med ett sandpapper av finhet K1000, har en värmesänkning på -9.3 °C, motsvarande en 23% sänkning av utgångstemperaturen, uppnåtts för tätningen efter en timmes drift. På liknande sätt resulterade kylning av tätningsvätskan i en värmesänkning på -5.4 °C, vilket är 13% svalare än utgångstemperaturen. Tillsammans bidrar parametrarna till en 36% lägre temperatur hos plantätningen efter en timmes drift i CultureOne Primo-maskinen. Således skulle de testade strategierna för att sänka plantätningars temperatur kunna användas för att möjliggöra valet av miljövänligare och billigare material.

This thesis aims to investigate the coefficient of friction between steel on steel contacts with the addition of solid lubricants such as h-BN, WS2, MoS2 in powder form, in dry conditions and wet conditions. More specifically, the purpose is to enhance the sliding between the piston rings and cylinder block in a modern high temperature steam engine developed by RANOTOR. The friction test was carried out as a linear sliding test with determined loads and sliding speed. Hertzian contact theory was deployed to calculate contact pressure and shear stresses to make sure the contact was elastic, alternatively plastic. It was found that WS2 and  MoS2 lowered the coefficient of friction quite heavily in dry conditions, acting as a thin protective-lubricating film. h-BN performed rather poorly, increasing the coefficient of friction. In a water slurry, none of the powders managed to decrease the COF due to the particles not interacting with the surfaces.The solid lubricants tested should be further tested as coatings since they acted like it in dry conditions. / Denna rapport syftar till att undersöka friktionskoefficienten i stålkontakter med tillsats av fasta smörjmedel som  h-BN, WS2, MoS2 i pulverform, under torra och våta förhållanden. Mer specifikt är syftet att förbättra glidningen mellan kolvringarna och insidan av cylindern i en modern högtemperatur-ångmotor utvecklad av RANOTOR. Friktionstestet genomfördes som ett linjärt glidtest med bestämda belastningar och glidhastighet. Hertzian-kontaktteorin användes för att beräkna kontakttryck och skjuvspänningar för att säkerställa att kontakten var elastisk alternativt plastisk. Det visade sig att WS2och MoS2 kraftigt sänkte friktionskoefficienten under torra förhållanden genom att agera som en tunn skyddande-smörjfilm. h-BN presterade dåligt och ökade friktionskoefficienten. I vattenblandning lyckades inget av pulverna minska friktionskoefficienten eftersom partiklarna inte interagerade med ytorna. De testade fasta smörjmedlen bör vidare testas som beläggningar eftersom de fungerade som dessa under torra förhållanden.

Icing severely affects society, especially in the Nordic countries. Iceaccumulation can result in critical performance problems and safetyconcerns for instance in road, air and sea transportation, transmissionlines, marine and offshore structures, wind turbines and heat exchangers.Present active ice-combating approaches possess environmental,efficiency and cost drawbacks. Thus, fabricating icephobic surfaces orcoatings impeding ice formation (anti-icing), but facilitating ice removal(de-icing) is desired. However, different conditions in the environmentduring ice formation and growth add to the complexity of the problem.An icephobic surface that works for a certain application might not be agood candidate for another. These surfaces and the challenges are infocus in this thesis.Wetting properties are important for ice formation on surfaces fromthe liquid phase (often supercooled water), where the water repellency ofthe surfaces could enhance their anti-icing effect. Considering this,different hydrophobic and superhydrophobic surfaces with differentchemistry, morphology and roughness scale were prepared. Since anyinduced wetting state hysteresis on hydrophobic surfaces could influencetheir performance, the wetting stability was investigated. In particulardynamic wetting studies of the hydrophobic surfaces revealed whatsurface characteristics benefit a stable wetting performance. Further, theeffect of temperature, particularly sub-zero temperatures, on the wettingstate of flat and nanostructured hydrophobic surfaces was investigated.This was complemented with studies of the wetting stability of sessilewater droplets on flat to micro- and multi-scale (micro-nano) roughhydrophobic samples in a freeze-thaw cycle. To be consistent with mostapplications, all temperature-controlled experiments were performed inan environmental condition facilitating frost formation. Further, antiicingproperties of hydrophobic surfaces with different topography butsimilar chemistry were studied by freezing delay measurements.A dynamic wetting study using hydrophobic samples with similarchemistry but different topography revealed that multi-scale roughnesscould benefit the wetting stability. However, when these surfaces areutilized at low temperatures the wetting hysteresis observed during acooling/heating cycle is significant. Such a temperature-inducedhysteresis is also significant on superhydrophobic surfaces. I attributethis to condensation followed by frost formation facilitating spreading of  the supercooled water droplet. The freezing delay measurementsdemonstrate no significant effect of surface topography on anti-icingproperties of hydrophobic surfaces, however the flat surfaces showed thelongest delay. These findings are in agreement with heterogeneous icenucleation theory, suggesting preferential ice nucleation in concave sites,provided they are wetted.In the second part of this thesis, I consider the findings from theprevious part illustrating the limitations of (super)hydrophobic surfaces.The de-icing properties of hydrophilic surfaces with a hydration waterlayer, hypothesized to lubricate the interface with ice, were studied. Heretemperature-controlled shear ice adhesion measurements, down to -25oC, were performed on an adsorbed layer of a polymer, either bottle-brushstructured poly(ethylene oxide) or linear poly(ethylene oxide). The iceadhesion strength was reduced significantly on the bottle-brushstructured polymer layer, specifically at temperatures above -15 oC,whereas less adhesion reduction was observed on the layer formed by thelinear polymer. These findings are consistent with differential scanningcalorimetry (DSC) data, demonstrating that the hydration water, boundto the bottle-brush structured polymer, is in the liquid state at thetemperatures where de-icing benefit is observed. Further, continuingwith the hypothesis of the advantage of surfaces with a natural lubricantlayer for de-icing targets, I studied shear ice adhesion on the molecularlyflat basal plane of hydrophilic mica down to -35 oC. Interestingly, ultralowice adhesion strength was measured on this surface. I relate this to theproposed distinct structure of the first ice-like but fluid water layer onmica, with no free OH groups, followed by more bulk liquid-like layers.This combined with the molecularly smooth nature of mica results in aperfect plane for ice sliding. / Isbildning har en stark inverkan på samhället, speciellt i de nordiskaländerna. Isuppbyggnad kan resultera i kritiska prestandaproblem ochsäkerhetsrisker inom t.ex. väg-, luft-, och sjötransport, kraftledningar,marina- och offshorestrukturer, vindkraftverk och värmeväxlare.Nuvarande aktiva isbekämpningsmetoder uppvisar brister i avseende påmiljö, effektivitet och kostnad. Det finns därmed ett behov av attframställa ytor eller ytbeläggningar som förhindrar isbildning (antiisning)eller underlättar borttagandet av redan bildad is (avisning). Dockkompliceras problemet av de många olika förhållanden under vilka is kanbildas. En beläggning som fungerar för en viss tillämpning behöver intenödvändigtvis vara en bra kandidat för en annan. Dessa ytor ochutmaningar relaterade till dem är i fokus i denna avhandling.Vätningsegenskaper är viktiga för isbildning på ytor från vätskefas(ofta underkylt vatten), och det har visats att vattenavstötande ytor i vissasammanhang kan motverka isbildning. Med detta i åtanke framställdesolika hydrofoba och superhydrofoba ytor, med varierande kemi,morfologi och ytråhet. Eftersom en förändring i de hydrofoba ytornasvätningsegenskaper kan påverka deras funktion studerades vätningsstabilitetenför dessa ytor. I synnerhet dynamiska vätningsstudier av dehydrofoba ytorna avslöjade vilka ytegenskaper som är fördelaktiga förvätningsstabiliteten. Vidare studerades hur temperaturen, särskilt undernoll grader, påverkar vätningstillståndet på släta och nanostruktureradehydrofoba ytor. Arbetet kompletterades med studier av vätningsstabilitetenför vattendroppar på släta samt mikro- och multistrukturerade(mikro-nano) hydrofoba ytor under flera frysningsupptiningscykler.För att vara i linje med de flesta tillämpningar, utfördesalla temperaturkontrollerade mätningar i en miljö där frost kunde bildaspå ytorna. Anti-isegenskaperna hos de hydrofoba ytorna med varierandetopografi men samma kemi studerades vidare genom att studera hur långtid det dröjde innan en vattendroppe på ytan fryste vid en visstemperatur.De dynamiska vätningsstudierna på hydrofoba ytor med samma kemimen olika topografi avslöjade att en ytråhet på flera längdskalor kan haen positiv inverkan på vätningsstabiliteten. När dessa ytor är exponeradeför låga temperaturer är dock vätningshysteresen under en nedkylnings-/uppvärmnings-cykel significant. Den temperatur-inducerade hysteresenär också betydande för superhydrofoba ytor. Detta tillskriver jag  kondensation på ytan som följs av frostbildning, vilket i sin tur möjliggörspridning av den underkylda vattendroppen på ytan. Mätning avfördröjningen i frysningsförloppet påvisade ingen betydande effekt avyttopografin för hydrofoba ytor, men släta hydrofoba ytor uppvisade denlängsta fördröjningen. Dessa resultat är i överensstämmelse med rådandeheterogen iskärnbildningsteori, som visar på fördelaktig iskärnbildningpå konkava delar av ytan, förutsatt att dessa väts.I den andra delen av avhandlingen utnyttjar jag observationerna frånden första delen vilka illustrerade begränsningarna för superhydrofobaytor, och söker en annan lösning. Avisningsegenskaper för hydrofilastarkt hydratiserade ytor studerades, med hypotesen att hydratiseringkan smörja gränsskiktet med is. Temperatur-kontrolleradeisadhesionsmätningar ned till -25 °C utfördes på adsorberade skikt av enpolymer med många sidokedjor av polyetylenoxid (”bottle-brush”), såvälsom på ett skikt av linjär polyetylenoxid. Isadhesionen blev kraftigtreducerad på ”bottle-brush”-polymeren, speciellt vid temperaturer högreän -15°C. Däremot kunde knappast ingen minskad isadhesion observerasför den linjära polymeren. Dessa observationer överensstämmer meddifferentialskanningskalorimetri (DSC) data, som visar att dethydratiserade vattenskiktet, vilket är bundet till ”bottle-brush”-polymeren, är i vätskeform vid de temperaturer där avisningsfördelar ärobserverade. För att vidare undersöka hypotesen att det vore fördelaktigtmed ett naturligt smörjande skikt på ytan för att uppnå godaavisningsegenskaper, utförde jag isadhesionsmätningar på molekylärtsläta glimmerytor ner till -35 °C. Intressant nog uppmättes extremt lågisadhesion på denna yta. Detta relaterar jag till den föreslagna utprägladehydratiseringsstrukturen, bestående av ett första is-liknande vattenskiktutan fria OH-grupper, följt av ett mer bulkliknande skikt. Detta ikombination med den molekylärt släta naturen hos glimmer resulterar iett perfekt plan för isen att glida på. / <p>QC 20160504</p> / TopNano

Additive Manufacturing (AM) for metals includes is a group of production methodst hat use a layer-by-layer approach to directly manufacture final parts. In recent years, the production rate and material quality of additive manufactured materials have improved rapidly which has gained increased interest from the industry to use AM not only for prototyping, but for serial production. AM offers a greater design freedom, compared to conventional production methods, which allows for parts with new innovative design. This is very attractive to the aerospace industry, in which parts could be designed to have reduced weight and improved performance contributing to reduced fuel consumption, increased payload and extended flight range. There are, however, challenges yet to solve before the potential of AM could be fully utilized in aerospace applications. One of the major challenges is how to deal with the poor fatigue behaviour of AM material with rough as-built surface. The aim of this thesis is to increase the knowledge of how AM can be used for high performance industrial parts by investigating the fatigue behaviour of the titanium alloy Ti6Al4V produced with different AM processes. Foremost, the intention is to improve the understanding of how rough as-built AM surfaces in combination with AM built geometrical notches affects the fatigue properties.This was done by performing constant amplitude fatigue testing to compare different combinations of AM material produced by Electron Beam Melting(EBM) and Laser Sintering (LS) with machined or rough as-built surfaces with or without geometrical notches and Hot Isostatic Pressing (HIP) treatment. Furthermore, the material response can be different between constant amplitude and variable amplitude fatigue loading due to effects of overloads and local plastic deformations. The results from constant amplitude testing were used to predict the fatigue life for variable amplitude loading by cumulative damage approach and these predictions were then verified by experimental variable amplitude testing. The constant amplitude fatigue strength of material with rough as-built surfaces was found to be 65-75 % lower, compared to conventional wrought bar, in which HIP treatments had neglectable influence on the fatigue strength. Furthermore, the fatigue life predictions with cumulative damage calculations showed good agreement with the experimental results which indicates that a cumulative damage approach can be used, at least for a tensile dominated load sequences, to predict the fatigue behaviour of additive manufactured Ti6Al4V.

This bachelor’s degree project aimed to improve the wheel profile of a rail mounted trolley and determine the cause of wheel failure. The proceedings of this project where modelled after an approach for solving wear problems with an emphasis on designing for sustainability. A case study and root cause analysis (RCA) was performed and the flanged wheels were deemed insufficient for the given heavy-haul system. Possible areas of wheel profile improvement were identified and further researched with multiple literature reviews. Throughout the projects duration several limitations were introduced that reduced the concept testing to exclusively theoretical prediction models. Archard’s model was implemented to predict wear and operating time for the proposed material and wheel tread profile concepts. The wheel flange dimensions were chosen based on recommendations from wheel and rail interference handbooks among other sources. The final wheel and rail profile suggestion improved operating time by approximately 300% and wear resistance by 50% compared to its predecessor. This result was achieved by applying the same theoretical prediction model to both current and suggested profiles. The findings of this project are meant to aid SCA among others in similar cases and additionally highlight the value of product improvement from a technological, sociological, and environmental perspective.

Most of the rolling element bearings are lubricated with Grease lubricant. Generally, the grease is expected to serve for life. The major causes of the bearing failure are due to the failure of the lubrication. The grease will experience creeping, oil permeation, oil separation etc. The separated oil will be lost permanently from the bearing. The widely used grease for general application is the lithium grease. The thickener of the grease consists covalent bond. When the grease is sheared, the breakage of the covalent bond will be permanent, resulting in the permanent loss of the rheological properties. The gels have unique properties such as thermal reversibility, viscoelasticity and thixotropy. They become mobile under shear stress and solidify again when the shear stress is removed. This property can be harnessed to avoid the base oil creeping, oil permeation, leakage in gears and bearings. Due to the presence of the polar group in the gels, they form a good tribo film and prevent the wear.  Under the shear stress, weak supramolecular interactions will be distorted, and this leads to the release of the oil and they re-form the structure after a certain period of rest. When the gel is in the solid-state, it will avoid creeping and evaporation. Many classes of gels are either derived from natural sources or from environmentally friendly materials. Thus, the lubricant formed out of gel would effectively solve both environmental as well as lubrication problems. In this work, supramolecular gel lubricants were prepared out of fully green, cellulose derivatives and starch hydrolysates. The non-ionic hydroxyethyl cellulose (HEC) and anionic sodium carboxymethyl cellulose (NaCMC) were chosen to understand the effect of ionic and non-ionic gelators on the rheological and the tribological parameters. Traditionally fat was used as a lubricant, now, in food industry various fat replacers are being used. To study whether the fat replacers can act as a thickener, Dextrin and maltodextrins were chosen.  Dextrin and maltodextrin with the different DE values were selected to understand the influence of molecular weight on gelation and tribological performance.  Inspired by the recent developments and advantages of aqueous lubrication, mixer of water and poly(ethylene glycol) 200 (PEG 200) is chosen as the base fluid. It was found that a very small amount of gelator can increase the viscosity of the PEG/water to several orders. The thermal stability of the gels was studied using thermogravimetric analysis (TGA) and found that gels can increase the thermal stability of the base fluid. FTIR results showed the formation of a non-covalent bond between the PEG molecules and water. It is shown that anionic gelator will result in producing low friction and wear in comparison to non-ionic gelator. The possible tribo-film formation due to the negative charge in the NaCMC molecules is attributed to these results. The very low friction and low wear was exhibited by the dextrin and maltodextrin gels. It is proposed that this could be due to the microspherical particles of gels which can act as nano bearings. It was found that choosing the optimum concentration of the gelator is important to reduce friction and wear. The higher gelator concentration will form the hard gel, which cannot flow and replenish the sliding contact, resulting in the starved lubrication. This will cause high wear and friction. These gel lubricants can be used in food, pharmaceutical and biomedical industries.