Tribological Investigation Research Articles

STUDY ON THE TRIBOLOGICAL PROPERTIES OF A356/AL2O3 AND PARAMETRIC OPTIMIZATION OF WEAR BEHAVIOUR USING TAGUCHI AND RSM

Metal Matrix Composites are considered to be the center of research in materials due to their superior properties (mechanical as well as tribological) and applications. Hence, Tribological investigation of A356 (Si7 mg0.3 Fe0.2) alloy reinforced with Al2O3 nano particles (Avg <50nm) are studied and presented in this work. The specimens for the experimentation were prepared using Powder metallurgy route. Reinforcements were taken to be in concentrations of 0wt%, 2wt% and 4wt% and blended with the matrix. Tribological characterization was done with the use of Pin on Disc apparatus for varying load conditions (20, 30 & 40N) and speed conditions (400, 600 and 800rpm). Results clearly show that the rate of wear and frictionco-efficient is reduced by a larger extent due to the addition of Al2O3. Micrographs of worn surfaces showed the larger grooves which showed the material loss and it can be seen that the surface is less rough in the case of 4wt% reinforcement composite.

Tribological investigation and process optimization of dry sliding wear behavior for WS2 solid lubricant layer deposition on Al 6061-T6 surface

PurposeThis tribological investigation aims to identify the effect of WS2 deposition on the Al 6061 surface and optimize the dry sliding conditions to enhance the friction and abrasion wear behavior.Design/methodology/approachWS2-deposited Al 6061-T6 surface was considered for this tribological investigation. The design of the experiment was based on the Box–Behnken design of the response surface methodology approach, which is used to evaluate the interaction effect of input parameters on friction coefficient (COF) and specific wear rate (SWR). The abrasive wear behavior of WS2 deposition against SiC emery sheet was explored through pin-on-disc experimentation by varying applied load (L), sliding velocity (V) and distance (D). Using analysis of variance and regression model, COF and SWR were predicted.FindingsBased on composite desirability criteria, multi-objective optimization was performed to minimize the COF and SWR. The obtained optimal sliding conditions are L = 10 N, V = 2 m/s and D = 949.49 m. The validation test results indicate that the experimental and predicted data are in good conformance. For optimized conditions, worn surface characterization was done using a scanning electron microscope with energy dispersive spectroscopy, and X-ray diffraction analysis was performed to ensure the formation of WS2 phases on worn-out surfaces. Furthermore, a counter body surface with collected wear debris has been analyzed.Originality/valueAlmost the industries are now focused on a new surface modification technique, which improves the surface and tribological characteristics. This research work specifically relates the tribological effect of WS2 deposition on an Al 6061-T6 surface through a novel electrical discharge deposition approach and optimizes the dry sliding conditions to improve the frictional and abrasive wear resistance.

Influence of heat treatment on the microstructure, mechanical and tribological performances of particle reinforced aluminum matrix surface composite fabricated through friction stir processing

In this investigation, TiC reinforcements were incorporated into Al-Zn-Mg-Cu alloy by integrating reverse engineering and geometry reconstruction technique with a surface composite being developed through the recursive method of friction stir processing (FSP). The fabricated composite was further subjected to T6 and RRA heat treatments and its microstructural changes, mechanical and tribological properties examined. Microstructural studies revealed the formation of well refined equiaxed grain structure with a reduced average grain size of 2.40 µm for the FSPed composite and 2.90 and 3.03 µm for T6 and RRA heat treated composites, indicating that grain growth and recrystallization were inhibited effectively by the presence of uniformly dispersed TiC particles during FSP and heat treatments. Improved distribution of hardness with an average of 208.64 HV was observed for the FSPed composite. After T6 and RRA treatments, average hardness was enhanced to 244.29 and 230.26 HV due to the additional strengthening caused by the precipitates. Tribological investigations revealed better wear resistance for the heat treated composites compared to the as-FSPed composite. The presence of a hardened surface with TiC rich tribo-layer and finely distributed precipitates stifled the extent of plastic deformation and improved wear resistance.

Tribological investigation of Molybdenum disulphide nanoparticles and Graphene nanoflakes as lubricant additives in Karanja oil

Tribological investigation of Molybdenum disulphide nanoparticles and Graphene nanoflakes as lubricant additives in Karanja oil

Tribological Investigation of a Mixed Solution with Superlubricity Achieved

Tribological Investigation of a Mixed Solution with Superlubricity Achieved

Tribological investigation of molybdenum disulphide nanoparticles and graphene nanoflakes as lubricant additives in Karanja oil

Tribological investigation of molybdenum disulphide nanoparticles and graphene nanoflakes as lubricant additives in Karanja oil

Tribological analysis of advanced microwave synthesized Molybdenum disulfide (MoS2) as anti-friction additives in diesel engine oil for military vehicles

One of the most important method to reduce friction and wear is lubrication which is important in the automotive industry for energy efficiency, environmental conservation, and carbon reduction. Additionally, incorporating nanoparticles into engine oil lubricants can significantly increase their performance, particularly in terms of tribological properties. Advanced microwave synthesized Molybdenum disulfide (MoS2) anti-friction additive in SAE 20 W50 diesel engine oil was employed to formulate the nanolubricant. Fourier-transform infrared spectroscopy (FTIR) and a physical stability observation test was used to study the nano additives' physicochemical qualities (MoS2). The tribological performance of the MoS2 nanolubricant was measured using the four-ball tribotester. The Coefficient of Friction (COF) and average Wear Scar Diameter (WSD) of the anti-friction additives were analysed through tribological investigations of the wear rate and scar of the worn-out surface on ball bearings. MoS2 based nanolubricant improves COF and WSD by 10.25 % and 10.6 % respectively, as a contrast to the engine oil revealed from the tribological analysis. The current study discovered that the engine oil with advanced microwave synthesized nanoparticles have a significantly lower COF and WSD than engine oil which is not added with the anti-friction additives.

Otkrivanje mogućih oštećenja motora u slučaju vojnih vozila sa kontinualnim kolosekom sa tribološkim istraživanjima

Detecting the engine failures of the continuous track military vehicles is challenging because their engines are always built-in narrow places covered with armored plates. In the case of the older engines, modern computer diagnostics cannot be used for failure analysis; the solution for these tasks is the visual analysis with the engine disassembly. A possible cost-effective failure analysis method can be the tribological and chemical analysis of the used oil from the engine, which can eliminate the engine disassembly work and as the results of the chemical oil analysis can also provide information about possible fuel or cooling water dilution or the increased wear of engine components. The main goal of this article is to present the failure analysis method through the tribological investigation of the engines of two PTSZ-M type medium-tracked amphibious military transport vehicles.

Consequences of variation in oxygen partial pressure on zirconium oxide thin films

RF magnetron sputtering was used to deposit zirconium oxide thin films with oxygen as the reactive gas and argon as the inert gas. The effect of increasing the oxygen partial pressure from 17.0 to 50.0% on the structural, optical, wettability, and tribological properties of deposited films was examined. X-ray diffraction was used to characterize the structure of ZrO2 thin films, confirming the presence of a (1 1 1) peak whose intensity increases as the oxygen partial pressure decreases. Atomic force microscopy results indicate increase in surface smoothness values with decrease in oxygen partial pressure. Within the wavelength range of 300 nm to 700 nm, average transmittance values of roughly 80% were reported, demonstrating that zirconium oxide thin films are transparent. When utilizing a contact angle goniometer to measure contact angles for water and formamide liquids, the results show that the films are hydrophobic. The highest contact angle observed on zirconium oxide thin films are 102.6° and 101.3° for water and formamide liquids respectively. Tribological investigation shows that zirconium oxide thin films coated pins had a reduction of wear when compared to the uncoated pins.

Tribological investigation of HVOF sprayed Ni-based coatings on SS 316L in water-cooled nuclear reactor

The sodium and water-cooled nuclear reactors play a significant role in energy producing sectors. However, the maintenance of these reactors is more challenging. A 316L austenitic stainless steel are a major construction material used in nuclear reactors due to its high corrosion resistance. However, these components are subjected to wear due to its low hardness. The cobalt-based coatings were employed in some reactors for improving the wear properties. However, it has been observed that these coatings lead to the formation of Co-60 isotopes in the reactor and emits gamma rays, which are harmful to the maintenance personnel. Nickel based coating can be used as a substitute to the Co-based coating on SS 316L to avoid the risk involved. This paper presents the characterization of the HVOF sprayed Ni-based coating over SS 316L substrate and the wear and friction behavior of SS 316L and coating against silicon nitride at nuclear environment condition. The coating properties were obtained and presented. The friction and unidirectional sliding wear tests have been carried out using a pin on disc tribometer. The estimated mass wear rate for the coating has been found as 4.15 × 10-5g/Nm. The coating offers high wear resistance as compared to SS 316L material and hence recommended for the components of the water-cooled nuclear reactor.

Tribological investigation of chromium nitride coatings against stainless steel at elevated temperature

Chromium nitride coatings (CrN) are comprehensively utilized in medical fields because of their excellent wear properties as well as mechanical properties. The erosion properties of CrN coatings are better than other coatings. In this article, our main objective is to analyse the wear mechanisms and microstructure of nitride coated 316L steel at elevated temperature. Here, the stainless steel was coated by a hard Chromium Nitride using Cathodic Arc Deposition (CAD) technique. The wear test of coated surface was conducted with help of Pin on disc tribo meter at various loading conditions. During the wear test, the maximum number of debris produced due to oxidation peeling of the coatings were compacted to form a thick transfer film, resulting in badly adhesive wear. The wear mechanisms were adhesive and oxidation wear accompanied with abrasive wear at elevated temperature (400 °C).

Tribological and Rheological Investigations of MWCNT/PMMA Polymeric Composites and Hybrid Compounds

The Nano scale self-lubricating compounds were prepared by in-situ free radical polymerization with the dispersion of MWCNT ultrasonic molecules embedded in the polymer matrix to enhance the tribological mechanical properties as well as the production of hybrid compounds to detect the tibial changes on the polymer surface, dry friction under the conditions of slip was studied, the friction coefficient was found For hybrid compounds slightly lower than the coefficient of friction of Nano composites under multiple loads and constant velocities, enhancements of Nano composites in rheological behavior were investigated and the influencing factors were determined: shear stress, shear viscosity, as well as shear rates. By using visual inspection, tracking of the behavior of compounds during extrusion was carried out and obtaining the shapes of the threads resulting from extrusion, which are usually important matters whose results depend on many industries.

Comparative tribology II–Measurable biphasic tissue properties have predictable impacts on cartilage rehydration and lubricity

Healthy articular cartilage supports load bearing and frictional properties unmatched among biological tissues and man-made bearing materials. Balancing fluid exudation and recovery under loaded and articulated conditions is essential to the tissue's biological and mechanical longevity. Our prior tribological investigations, which leveraged the convergent stationary contact area (cSCA) configuration, revealed that sliding alone can modulate cartilage interstitial fluid pressurization and the recovery and maintenance of lubrication under load through a mechanism termed ‘tribological rehydration.’ Our recent comparative assessment of tribological rehydration revealed remarkably consistent sliding speed-dependent fluid recovery and lubrication behaviors across femoral condyle cartilage from five mammalian species (equine/horse, bovine/cow, porcine/pig, ovine/sheep, and caprine/goat). In the present study, we identified and characterized key predictive relationships among tissue properties, sliding-induced tribological rehydration, and the modulation/recovery of lubrication within healthy articular cartilage. Using correlational analysis, we linked observed speed-dependent tribological rehydration behaviors to cartilage's geometry and biphasic properties (tensile and compressive moduli, and permeability). Together, these findings demonstrate that easily measurable biphasic tissue characteristics (e.g., bulk tissue material properties, compressive strain magnitude, and strain rates) can be used to predict cartilage's rehydration and lubricating abilities, and ultimately its function in vivo. Statement of significanceIn healthy cartilage, articulation recovers fluid lost to static loading thereby sustaining tissue lubricity. Osteoarthritis causes changes to cartilage composition, stiffness, and permeability associated with faster fluid exudation and presumably poorer frictional outcomes. Yet, the relationship between mechanical properties and fluid recovery during articulation/sliding remains unclear. Through innovative, high-speed benchtop sliding and indentation experiments, we found that cartilage's tissue properties regulate its exudation/hydration under slow sliding speeds but have minimal effect at high sliding speeds. In fact, cartilage rehydration appears insensitive to permeability and stiffness under high fluid load support conditions. This new understanding of the balance of cartilage exudation and rehydration during activity, based upon comparative tribology studies, may improve prevention and rehabilitation strategies for joint injuries and osteoarthritis.

A Review of Preparation and Tribological Applications of Pickering Emulsion

Abstract Pickering emulsion is a new type of stable emulsion made by ultrafine solid particles instead of traditional surfactants as stabilizers, which has received widespread attention in recent years. The preparation methods of stator-rotor homogenization, high-pressure homogenization, and ultrasonic emulsification were compared with others in this work. The main factors affecting the stability of Pickering emulsion are the surface humidity of the solid particles, the polarity of the oil phase, and the oil–water ratio. These factors could affect the nature of the solid particles, the preparation process of Pickering emulsion, and the external environment. Consequently, the long-term stability of Pickering emulsion is still a challenge. The tribological investigations of Pickering emulsion were summarized, and the multifunctional Pickering emulsion shows superior prospects for tribological applications. Moreover, the latest development of Pickering emulsion offers a new strategy for smart lubrication in the near future.

Tribological investigation on aluminum alloy 6082 reinforced with zirconium silicate/titanium carbide by Taguchi technique

In this research work, the aluminum metal matrix composites were prepared by stircasting method. Al6082 is a base metal which reinforced with zirconium silicate and titanium carbide. Wear characteristic were analysed with help of pin on disc apparatus. totally nine samples were produced by changing reinforcement percentage to conduct the test. optimization parameters of wear rate are examined by taguchi’s technique (L9 orthogonal array). With usage of MINITAB-18 software ,SN ratio, analysis of variance and regression equation for wear parameters such as load, sliding speed and reinforemnet weight percent are determined. the results reveled that load is primary optimal factor around 59.8% ,followed by wt % of reinforcement (38.42%) as second optimal value and sliding speed (1.78%) as a least parameter.

Tribological characteristics of mahua oil with graphene nanoplatelets as anti-wear and extreme pressure additive

The tribological investigation was performed to seek the role of graphene nanoplatelets (GNPs) in enhancing the physico-tribological properties of mahua oil. The flashpoint, fire point, viscosity, wear preventive characteristics (WPC) and extreme pressure characteristics (EPC) were conducted following the governing standards. A substantial decrement of 17% in the coefficient of friction, 15.15% in wear scar diameter was observed upon blending the 0.25 wt.% GNPs with mahua oil. The WPC morphology on the steel balls portrayed the micro tracks. The EPC investigation presented 1 wt.% GNPs blended mahua oil with the augmented outcome of 7.7% and this was portrayed to be the best GNPs loading in weld load perspective. However, at 0.1 wt.% of GNPs loading was identified as the best loading with a wear point of view. The morphology of EPC revealed severe abrasion and steel balls were exposed to very high temperatures and have undergone metal squeeze out from the contact surface. This article also discusses the different wear regimes and corresponding wear phenomena in four-ball tribology testing with the aid of micrographs.

Tribological investigation of quality of the industrial speed reducer synthetic lube oil used in material handling industry

Industrial gear reducers regulate the speed of conveyors, cranes and hoist systems as well as mixing and other equipment. Optimal operating conditions must be defined in order to ensure efficient operation and minimize downtime due to any problems. Processes that need regulated torque output range from complex to simple, depending on their complexity. The objective of experimental investigation is to perceive the deterioration interaction of Industrial Reducer oil and inspect the effect & impact of debasement on the overall quality of synthetic oils utilized in mechanical reducers. An experimental test rig having mechanical reducer driven through AC motor (25 HP) is utilized for this assessment. Unused Industrial gearbox lubricating oil (IOCL Servo Gear HP 140) is utilized for overall performance assessment evaluation in mechanical reducer. The synthetic oil test was collected at various time intervals from test arrangement. The performance of utilized synthetic oil was evaluated based on oil properties. The viscosity was reported to be decreasing due to friction, while the total acid number was reported to be increasing due to lubricating oil oxidation.

Insight into the Lubrication and Adhesion Properties of Hyaluronan for Ocular Drug Delivery.

Hyaluronan (HA) is widely used for eye drops as lubricant to counteract dry eye disease. High and low molecular weight HA are currently used in ophthalmology. However, a large portion of the current literature on friction and lubrication addresses articular (joint) cartilage. Therefore, eye drops compositions based on HA and its derivatized forms are extensively characterized providing data on the tribological and mucoadhesive properties. The physiochemical properties are investigated in buffers used commonly in eye drops formulations. The tribological investigation reveals that amphiphilic HA-C12 decreases the friction coefficient. At the same time, the combination of trehalose/HA or HAC12 enhances up to eighty-fold the mucoadhesiveness. Thus, it is predicted a prolonged residence time on the surface of the eye. The incorporation of trehalose enhances the protection of human keratinocytes (HaCaT) cells, as demonstrated in an in-vitro cell-desiccation model. The presence of trehalose increases the friction coefficient. Medium molecular weight HA shows significantly lower friction coefficient than high molecular weight HA. This research represents a first, wide array of features of diverse HA forms for eye drops contributing to increase the knowledge of these preparations. The results here presented also provide valuable information for the design of highly performing HA-formulations addressing specific needs before preclinic.

Tribological investigations into pin-on-disc tribometer under dry sliding conditions at various temperature ranges

In this research work, the interaction of aluminum alloy (6061) and EN-31 steel is examined, and interaction is studied on the basis of tribological outcomes under dry sliding conditions at various ranges of temperature. The extrusion process is actually an intricate process, which depends on environmental temperature, sliding velocity with respect to the mating part, the type of external shape, wear and coefficient of friction. Here, variables which directly or indirectly influence the interactions are designed for this system in such a manner that the results can be co-related with another system that has equivalent working condition as there in hot forming and cold forming (up to 250°C) of material interactions. The current work is done on a pin which slides on a disc of aluminium alloy 6061 and EN-31 steel set-up. Experiments are carried out under different conditions by using the design of experiments (DoE) for each case. In the first case (Case-I), the disc is steel and the aluminum alloy works as a pin. In the second case (Case-II), the disc is aluminum alloy and steel works as a pin. Henceforth, frictional coefficient and difference in the weight or wear (volume loss) before and after experiment is achieved. Finally, experiments are designed with the help of design tool to optimize the results and execute the different parameters by involving the analysis of variance . Lower wear volume loss is observed in a steel disc compared to the aluminium alloy pin at room temperature.

Tribological investigations of trimethylolpropane trioleate bio-based lubricants

PurposeThe screening of lube oil performance prior to field trials is the most significant for the formulation of novel lubricants. This paper aims to investigate the efficacy of trimethylolpropane trioleate oil (TMPTO) based lubricants with different additives.Design/methodology/approachIn this endeavor, initially five lubricating blends along-with TMPTO based oil with variable additives were evaluated for their tribological performances using ASTM standards. Out of these, the top three best-performing oils were further investigated for possible physical or chemical synergies among lube oils, additives and ball surface using SEM. The molecule structures of TMPTO based lube oils were confirmed using Fourier transform infrared spectroscopy (FTIR).FindingsThe wear preventive and extreme pressure characteristics of different TMPTO based samples were evaluated and compared for compatibility and synergy of additives. Morphological analysis of SEM images was used to understand the wear behavior of the worn surfaces.Practical implicationsFurther investigation of TMPTO oil on its oxidation stability at high temperature and pressure to make it technologically competitive and commercially viable metal-working lubricant is suggested.Originality/valueThis paper highlights the tribo-effects of TMPTO to be rendered as a suitable lubricant for metal-cutting operations. The surface morphology of the worn-out surface significantly demonstrates the effect of loading conditions.