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A hybrid lubricant with improved thermal and tribological properties was developed by blending multiwalled carbon nanotubes (MWCNTs) with alumina-based nanoparticles into cutting fluid at fixed volumetric proportions (10:90). The hybrid cutting fluid was prepared in different volumetric concentrations (0.25, 0.75, and 1.25 vol%), and the tribological properties and contact angles were measured using pin-on-disc tribometry and goniometry, respectively. The study showed a reduction in wear and friction coefficient with increasing nanoparticle concentration. The cutting fluid performance was investigated using minimum quantity lubrication (MQL) in the turning of AISI 304 stainless steel. Regression models were developed for measuring the temperature and tool flank wear in terms of cutting speed, feed, depth of the cut, and nanoparticle concentration using response surface methodology. The developed hybrid nanolubricants significantly reduced the tool flank wear and nodal temperature by 11% and 27.36%, respectively, as compared to alumina-based lubricants. Friction 7(2): 153-168 (2019) | https://mc03.manuscriptcentral.com/friction Friction 7(2): 153-168 (2019) | https://mc03.manuscriptcentral.com/frictionFriction 7(2): 153-168 (2019)

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The paper investigates the exceptional antiwear and extreme pressure properties of multiwalled carbon nanotube based mineral oil. Different samples of oil containing varying proportions of MWNT (MWNT) and graphite were prepared. The samples were tested for their antiwear and load bearing capacity according to ASTM G99 and ASTM D-2783 standards. After pass load test in four ball tester the rubbed surfaces were investigated with Scanning Electron Microscope (SEM) images. The wear test results show a decrease wear by 70-75% in case of multiwalled nanotube based mineral oil as compared with pure mineral oil. Furthermore, it has been observed that the load bearing capacity in case of multiwalled carbon nanotube based mineral oil increases by 20% as compared to pure mineral oil. A comparison in the antiwear and load bearing capacity properties of graphite and nanotube based mineral oil was studied which showed the inefficiency of graphite based lubricant over MWNT based oil. Thus, the finding would be helpful in developing new nanoparticle based lubricants.

XRD analysis of hydrothermally synthesized polymorphic MnO2 nanorods and their frictional torque when added with palm oil as against pure palm oil.

The present work investigates the tribological properties of castor oil with various carbonaceous friction modifiers (nano and microsize additives) assessed using four-ball tester as per ASTM D 4172 and ASTM D 2783. Castor oil has been chosen because of its high viscosity and ease of availability. Graphite, multiwalled carbon nanotube (MWCNT), and multilayered graphene are used as friction modifiers (FMs) in castor oil on weight percentage basis. Significant enhancements of tribological properties with a certain level of concentration of friction modifiers have been observed. The surface features of the tested balls were analyzed using a three-dimensional noncontact type profilometer, scanning electron microscope (SEM), and energy dispersive system (EDS). Decrease in surface roughness indicated better antiwear properties in case of nanofriction modifiers-based castor oil as compared to micrographite-based and neat castor oil (NCO). In order to assess the suitability of castor oil as a replacement for mineral oil, the results of castor oil samples are also compared with commercially available mineral oil. The tribological properties of castor oil are found to be competitive and generally superior to the mineral gear oil. The data generated are used to develop a neural network model to map the input–output correlation.

Various blends containing glycerol, castor oil (NCO) and cashew nut shell liquid (CNSL) were made following soft computational techniques and the blend consisting 60% glycerol and 40% NCO was proposed, which exhibited 37% less coefficient of friction (CoF) than NCO and CNSL and 50% less CoF and comparable extreme pressure properties to non-biodegradable commercial mineral oil (CMO). Accelerated wear was indicated by particle quantifier index for CMO, NCO and CNSL samples while normal wear was observed in glycerol and the proposed blend. SEM and 3-D profilometer images exhibited more damaged surfaces in NCO and CNSL than other lubricants. Raman spectra indicated the presence of FeOOH, OH, HOH and fatty acids on the wear tracks of the proposed blend.