Taguchi optimization of various parameters for tribological performance of polyalphaolefins based nanolubricants

This research paper addresses the optimization of various control parameters by using the Taguchi method to assess the tribological properties of PAOs based nanolubricants. The concentration of COOH-functionalized multiwalled carbon nanotubes (MWCNTs), applied load, sliding velocity and kinematic viscosity of polyalphaolefins (PAOs) were selected as process parameters or control factor. The MWCNTs at a varying concentration (0.025-0.15 wt.%) were blended separately in PAOs to formulate the nanolubricants. The tribological experimentations were performed by Taguchi’ L18 mixed orthogonal array using “ball on disc” type tribometer. The analysis of variance (ANOVA) was adopted to estimate the most prominent factors influencing the tribological performance of nanolubricants. The statistical results showed that the applied load, followed by a concentration of MWCNTs conferred the most significant impact on the frictional characteristic. In contrast, the kinematic viscosity of PAOs, followed by concentration of MWCNTs has been observed the most significant influencing factors on the antiwear properties of nanolubricants. The probabilistic rationale for the advancement in friction and wear properties were assessed through various analytical tools.

Frictional Characteristic of Polyoxymethylene/Steel-40Cr under Different Lubrication Condition

The friction characteristics of POM-40Cr are studied. The influence of each factor including the roughness, lubricant, pressure, contact area and speed on the friction force are determined by rotating motion pin-on-disc experiments in CETR-UTM friction testing machine. At the same time, the Stribeck curve of POM-40Cr is observed according to the change of velocity. Finally, the friction hysteresis phenomenon is studied by reciprocating pin-on-block experiments.

Frictional characteristic of sintered iron in high temperature

Purpose This paper aims to study the change rule of sintered iron friction properties under high temperature and establish the model to predict the friction coefficient. Design/methodology/approach The morphological measurements of sintered iron material with four different oxidation degrees are carried out. A prediction model of friction coefficient in high temperature oxide growth stage for sintered iron material is established based on the theory of flash temperature and adhesion friction. The relationship between friction coefficient and the key parameters is found through the test fitting. Findings The surface topography changes with oxidative wear. The wear debris will be compacted and sintered again to form a composite oxide layer with the temperature increasing. The validity and accuracy of proposed model are tested using the friction coefficient and temperature experiments. Results are in reasonable agreement with those obtained using values of load commonly used. Originality/value The significance lies in the change mechanism of high temperature friction characteristic is clarified. Three friction stages related to temperature of dry friction are put forward for sintered iron, and a meaningful reference is provided by the established model for high-temperature performance design of sintered iron friction material.

Investigations on Wear and Frictional Characteristic of Hybrid Polymer

This study targets on wear and frictional characteristics of hybrid polymer. Experiments are carried out on hybrid polymers using reciprocating wear testing machine by sliding against mating steel plate. General purpose resin is blended with Cashew nut shell is used as test specimen. The values of frictional force, frictional coefficient and wear were measured to study the influence of accelerated wear.