Tribological Investigation Research Articles

Experimental research on friction and wear behavior of dissimilar steel composite structure developed by wire arc-DED process for an automobile brake rotor application

Recent applications of dissimilar composite structures produced through the wire arc-direct energy deposition process are indispensable across various industries due to their lightweight hybrid components and superior mechanical and tribological properties. This process enables a novel way to fabricate of custom-designed, high-performance composite structures that optimize friction, wear resistance, and mechanical characteristics. The present study focuses on developing a dissimilar steel composite structure using wire arc additive manufacturing process, with tribological and microstructural investigations conducted to understand the interfacial wear properties of the alloys. Standardized specimens were prepared to assess their friction and wear behavior through pin-on-disc wear test-rig. Experimental results show that the composite specimens exhibit enhanced wear resistance even under extreme sliding conditions (50 N applied load and 2400 m sliding distance), with tribolayer formation confirmed through FESEM micrographs and EDAX analysis. The highest specific wear rate (SWR) (3.87E-04 mm³/Nm) was observed at 50 N, 6.28 m/s, and 1600 m sliding distance, with a friction coefficient of 0.26. Adhesive wear was identified as the dominant wear mechanism between the specimen and the counterpart. Taguchi's multiresponse optimization indicated that sliding distance had the most significant effect on SWR and friction coefficient, followed by applied load and sliding velocity.

INFLUENCE OF CONTACT TIME WITH LUBRICANTON POLYMER-POLYMER SLIDING PAIR INTERACTION

This paper presents tribological investigations of pairs of same-type construction polymers: PET, PA6, andPOM, which for different durations were in contact with a lubricant. Hydraulic oil HLP 68, used for heavilyloaded drive systems, was the lubricant. Test samples were subjected to storage in this lubricating mediumfor different lengths of time: ranging from no storage to 2 weeks of storage. The static friction coefficient,which has a significant bearing on the startup of systems, was studied. Furthermore, investigations aimed atidentifying the phenomena involved in the interaction of the polymer-polymer sliding pair were carried out.The duration of the storage of the polymeric materials in the lubricating medium has been found to have avisible effect on static friction coefficient values and surface hardness and condition.

Tribological investigation of new self-fluxing nickel alloys for high temperature application: the effect of silicon distribution on glaze layer formation

The objective of this study is to investigate the tribological performance of new nickel-based self-fluxing alloys for replacing cobalt-based alloys in aircraft components. Two new NiCrSiFeB alloys, manufactured by gravity casting and laser metal deposition processes, having different microstructures, are submitted to fretting loadings and tested at temperatures ranging from ambient to 650 °C. Their wear behavior is compared to a reference Stellite 6 cobalt- based alloy. Although the two NiCrSiFeB alloys have the same chemical composition, the alloy having a coarse microstructure rich in silicates was able to form a protective glaze layer at high temperature as Stellite 6. On the other hand, the alloy having a fine microstructure underwent severe adhesive wear. This highlights the crucial effect of the microstructure and the silicon distribution in activating the formation of a protective glaze layer at high temperatures.

Investigation of tribology and life prediction of polymer coatings on 7N21 aluminum alloy under dry sliding wear

To improve the tribological properties of the 7N21 aluminum alloy under dry sliding wear conditions, three E44-PI-PAI composite coatings filled with varying contents of MoS2, h-BN and VN were designed. The mechanical and tribological performances of these coatings were evaluated using scratch experiments, nanoindentation, and sliding wear experiments. After identifying the optimal coating, the engineering constants of the coating were determined using tensile experiments. Finally, a simulation analysis of the reciprocating wear life was performed using ABAQUS and a custom-developed UMESHMOTION subroutine. The results indicate that the optimal ratio of MoS2, h-BN and VN in the designed polymer coating is 4:3:4. The coefficient of friction (CoF) and wear rate of the optimal coating are 0.189 and 0.444×10−14 m3/Nm, representing a 67 % reduction in CoF compared to the 7N21 aluminum alloy. The L2 coating demonstrates excellent compatibility, featuring a surface roughness (Ra) of 0.630 μm, a uniform thickness of 10±2 μm, an optimal bonding strength at level 0, and a nanohardness of 0.391 GPa, meeting the requirements for engine bearings. The maximum deviation between the simulated wear life prediction and experimental results is only 8.11 %.

Tribological Investigation and Statistical Optimization by Response Surface Methodology of Vegetable Oil-Based Ionanolubricants

Tribological Investigation and Statistical Optimization by Response Surface Methodology of Vegetable Oil-Based Ionanolubricants

Synthesis and Tribological Investigation of Cashew Nutshell Liquid Cardanol Oil Dispersed with Modified Cu–Zn Nanoparticles

Synthesis and Tribological Investigation of Cashew Nutshell Liquid Cardanol Oil Dispersed with Modified Cu–Zn Nanoparticles

Investigation of sliding wear, electrochemical corrosion, and biocompatibility of Ti-Nb alloys for biomedical applications

This research emphasizes the development of biocompatible Ti-xNb (0, 5, 10, 15, 20, and 25 wt.%) alloys through powder metallurgy to attain a lower elastic modulus, high strength, low wear, and high corrosion resistance appropriate for biomedical implants. The developed alloys were comprehensively analyzed through microstructural, physical, mechanical, electrochemical, biological, and tribological investigations to assess their suitability by comparing their properties with commercially pure titanium (cpTi). The outcomes demonstrate, powder metallurgy is an effective route for developing Ti-Nb alloys with several desirable properties. Incorporating niobium (Nb) into titanium (Ti) introduces the β phase within the alloys, which increases with Nb concentration and contributes to decreasing the elastic modulus to as low as 43.47 ± 4.9 GPa. All Ti-Nb alloys exhibits higher hardness and compressive strength than cpTi, with values of 403.23 ± 21.38 HV and 1322.45 ± 25.64 MPa obtained for the Ti-10Nb alloy. A lower concentration of Nb shows comparable corrosion resistance of the Ti-Nb alloys to cpTi, whereas a higher Nb concentration is unfavorable. Furthermore, the tribological findings demonstrate superior antifriction and antiwear properties in all Ti-Nb alloys compared to cpTi. Notably, Ti-10Nb displays outstanding wear resistance with a 41.82% lower friction coefficient in dry conditions and 31.11% in simulated body fluid (SBF), along with 81.08% reduction in wear volume in dry conditions and 63.11% in SBF compared to cpTi. Among all developed alloys, Ti-10Nb exhibits various desired properties, suggesting its potential as an alternative to cpTi for biomedical implant applications.

Biomass-Derived Carbons as Friction Reducing Additives for Lubricants: Tribological Properties of Biochars and Activated Carbons Obtained from Sugar Cane Bagasse

Activated carbons are commonly used for adsorption/depollution applications, but only a few studies are related to their lubricating properties. In order to investigate a new family of friction reducers, the tribological properties of biochars and derived activated carbons obtained from sugar cane bagasse are investigated. Activated carbons are obtained from either a physical (steam water) or chemical (with phosphoric acid) activation process. The tribological tests show that the activated carbons present very low friction coefficients, close to 0.08. The correlation of textural and tribological investigations shows that the specific surface area of the compounds as well as the microporous and mesoporous domain extensions are key parameters to optimize the friction reduction properties of activated carbons. The friction properties of the compounds are improved if the mesoporous domain extension is above 40% of the total porous volume. This study shows that local biomass waste valorization is possible and that sugar cane bagasse-derived activated carbons appear as interesting new friction reduction additives for lubricants.

Tribological investigation of the new combustion chamber with wall-guided fuel injection in a diesel engine

Tribological investigation of the new combustion chamber with wall-guided fuel injection in a diesel engine

Nano-Diamond Decorated Reduced Graphene Oxide: Improvement to Tribological Property of Polyimide and Its Molecular Dynamic Simulation

In this paper, the nano-diamond decorated reduced graphene oxide (Diamond-RGO) and its polyimide (PI) composite, by using in situ polymerization method, are synthesized, respectively. The tribological study of Diamond-RGO/PI composite exhibits super anti-wear properties under dry sliding and high load condition: the lowest wear rate of 4.9 × 10−8mm3N−1m−1, which is extraordinarily lower than that of pure PI and RGO/PI composite, is obtained under load 100 N. The tribological mechanism investigation shows that Diamond-RGO composite has a strong synergistic effect in the tribological process which contributes to form a uniform transfer film on the counterpart ring and thus significantly decrease the composite’s wear rate. Through molecular simulation, the shear behavior of the composite material indicates that the presence of the Diamond-RGO composite will obviously weaken the influence of the iron wall on the PI bulk phase molecular chain in the shear process. This confirms that the synergistic effect between nano-Diamond and RGO will improve its PI composite’s tribological performance on atomic level.

Tribological Investigation on WC/C Coatings Applied on Bearings Subjected to Fretting Wear

Tribological Investigation on WC/C Coatings Applied on Bearings Subjected to Fretting Wear

Improvement in Tribological Properties with Addition of Hexagonal Boron Nitride (h-BN) and Molybdenum Disulfide (MoS2) Nanoparticles in Aerospace Lubricants

In the aircraft mounted accessory gearbox and gas turbine engine gearbox, a significant rise in temperature of lubricant was consistently observed due to the high coefficient of friction (COF) between the moving parts. This phenomenon limits the speed and power transmission of the gearbox. To resolve this, the current study recommends adding specific nanoparticles (NP) as an additive to the military (MIL) grade lubricant to reduce frictional resistance between the gears. Surfactants were also added to hexagonal boron nitride (h-BN) and molybdenum disulfide (MoS2) nanolubricants (NL) to improve NP suspension. Tribological investigations were conducted with a four-ball tester, a shear stability tester, and a Reichert tester to examine the lubricants. During the four-ball test, the wear scar diameter (WSD) on the specimen decreased by 16.73% and 12.3% with h-BN and MoS2 NL, respectively, compared to the results obtained using the base lubricant (BL). In the shear stability test, h-BN NL demonstrated 93%, and MoS2 NL demonstrated 67% more shear stability than the BL, while the COF was reduced by 13% in both h-BN and MoS2 NLs during the Reichert test. These test results prove that h-BN and MoS2 NPs, when added to a MIL standard BL, can demonstrate improved tribological capabilities even at extreme operational conditions.

Tribological investigations on fibre-reinforced composites: a comprehensive review considering variable velocity and load scenarios

Tribological investigations on fibre-reinforced composites: a comprehensive review considering variable velocity and load scenarios

A Tribological investigation of fly ash particulate‐loaded E‐glass fiber reinforced interpenetrating polymer network composites

AbstractEnvironmentally‐friendly materials are increasingly sought in use of both structural and non‐structural applications. Most of the prominent places, particulates and fibers are exclusively utilized to reinforce polymeric composites, aiming to enhance their strength and provide effective protection against wear. Currently, one of the most pressing issues encountered in current industries are wear and tear, mostly happens during manufacturing and agricultural operations. To overcome this issue, the current study examines into exploring the effects of different weight ratios (0%, 1%, 3%, 5%, 7%, 9% by wt.%) of fly ash (FA) loading on the abrasive characteristics of Interpenetrating Polymer Networks (IPNs) composites strengthened with E‐Glass fibers. Abrasion tests, conducted in accordance with ASTM D99 standard which involves five control parameters: load, FA content, speed, sliding distance, and surface roughness. Experimental design utilized Taguchi's orthogonal array (L25), with opts ANOVA to identify significant control factors. Results indicate that the addition of FA substantially enhances the wear resistance of particulate‐loaded E‐Glass fiber reinforced IPN composites. Moreover, the specific wear rate is significantly influenced by the applied load and FA content. However experimental data suggests that optimal wear behavior for IPN composites occurs under the conditions of 50 N load, 3% FA content, 300 rpm speed, 4000 m sliding distance, and 0.3 μm disc roughness. Further, scanning electron microscopy was also employed to examine microstructural details to better know the micro‐mechanism behavior happens between the particulates with fiber and matrix reinforcement.Highlights Utilization of fly ash significantly enhances composite strength. IPN laminates fabricated with 0%–7% particulate loads. IPN laminates thoroughly evaluated through wear testing. DOE guided experimental design using L25 orthogonal array. SEM analysis reveals superior quality of fly ash‐loaded IPN.

A robust method for assessing the macroscale tribological behaviour of solid lubricant nanoparticles

Reducing friction and wear is crucial for efficiency and longevity in tribological systems. Solid lubricant nanoparticles show great potential in this context but lack deposition control methods and tribological performance investigations under conditions closer to real systems. The present study used drop-casting to deposit multi-layer graphene (MLG) and carbide-derived carbon (CDC) nanoparticles on AISI1020 steel substrates. Tribological performance was evaluated using a ball on flat tests with an incremental load increase in a reciprocating motion. Results indicate a minimum coverage threshold for effective lubrication and highlight substrate topography's critical role. This research enhances understanding of nanoparticle deposition process optimization and control, showing an excellent tribological performance of MLG and CDC nanoparticles in solid lubricated systems.

A comparison of heat treatment effect on structural and tribological properties of tungsten rich Ni-W and Ni-W-P alloy coatings

In this paper, thick, metallic bright electrodeposited tungsten rich Ni–W–P alloy coatings with two different compositions Ni-36.3wt%W-3.3wt%P (designated as Ni–W–LP) and Ni-19.5wt%W-7.7wt%P (designated as Ni–W–HP) were chosen for comparison of heat-treatment dependent evolution of crystal structure, grain growth, nanohardness and tribological properties with respect to Ni-50.7wt%W coating. The systematic temperature dependent evolution of crystal structure and phases from as-deposited amorphous alloys were mapped using in-situ high temperature GIXRD investigation and peak-broadening analysis. Subsequent variation of nanohardness/microhardess was measured. Detailed tribological investigation of both as-deposited and heat-treated coatings was done by ball-on-plate dry sliding experiment and the observed coefficient of friction and wear data were correlated with measured nanohardness, H/E and H3/E2 ratio and a wear mechanism was proposed based on detailed FESEM investigation of wear scars.

Tribological investigation into nickel-coated graphite polytetrafluoroethylene composites

The friction and wear resistance of polytetrafluoroethylene (PTFE) composites can be enhanced by incorporating nickel-coated graphite. An electroless coating method employing Gin plates (418A, 418B) is utilized to produce nickel-coated graphite. X-ray diffractometer analysis reveals the presence of nickel and graphite peaks in the coated graphite powders at 44° and 26.4°, respectively. Scanning electron microscopy images confirm the presence of nickel coating on graphite particles. Tribological tests using a pin-on-disc tribometer (L9) demonstrate that composites filled with 20 wt.% Nickel-coated graphite exhibits the lowest wear rate of 220 µm, compared to 1166 µm for pure PTFE specimens. The notable improvement in wear resistance is attributed to enhanced bonding strength between the filler and matrix material. Pure PTFE exhibits varying coefficient of friction (CoF) at different parameters, with the highest and lowest CoF observed at 200 rpm, 20N and 180 rpm, 10 N, respectively. Optimal parameters for minimizing wear rate and CoF, determined through analysis of means, include a 20 wt.% filler concentration, disc speed of 180 rpm, and 10N load. Analysis of variance identifies composition and speed as primary factors affecting wear and CoF.

Tribological investigation of ceramic incorporated novel compositionally graded multilayer tungsten alloys

In this study, novel compositionally graded tungsten alloys incorporating ceramics were prepared using mechanical alloying and pressure-assisted vacuum hot press (VHP) sintering. Three distinct tungsten compositions (W1, W2, and W3) were developed with varying alloying elements and reinforcements, were stacked layer-wise, and then sintered using VHP. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were employed to analyze the morphology and microstructural features of synthesized alloys. The effect of alloying elements and reinforcements on mechanical properties and wear behavior was examined. The results showed improvement in mechanical characteristics and enhanced wear resistance of the compositionally graded tungsten alloys. The hardness was increased due to the formation of carbide phases during milling and sintering. The W1 side exhibited a hardness of 8.4 GPa, while the W3 side reached a hardness of 13.3 GPa. Additionally, the wear behavior of both sides (W1 and W3) was also investigated under different applied loads. At a load of 10 N, the W1 surface exhibited a minimum specific wear rate of 3 × 10−6 mm3/Nm, attributed to the presence of MWCNTs and WC phase. However, the W3 surface reinforced with TiC and cBN showed a minimum specific wear rate of 9 × 10−7 mm3/Nm at a higher load of 20 N. This indicates that the W3 side possessed superior hardness and wear resistance ability as compared to the W1 side of compositionally graded tungsten alloys. The novel compositionally graded approach is useful for developing tungsten alloys with tailored mechanical properties for wear resistance applications.

Tribological Investigations on Additively Manufactured Inconel 718 Features with Silicon Carbide Ball: Role of the Tribo-Oxide Layer

Tribological Investigations on Additively Manufactured Inconel 718 Features with Silicon Carbide Ball: Role of the Tribo-Oxide Layer

Tribological investigations of water-based lubricants for application in the deep drawing process

This paper describes the tribological investigation of water-based lubricants in the context of a deep drawing process. Therefore, different methods were conducted in order to determinate the suitability of these lubricants for a deep drawing process. Three lubricant manufacturers each provided their lubricants as part of this work. The sheet materials investigated are an aluminum material (AA6014) and two steel materials (DC04, DP800), each with a thickness of 1.5 mm. All sheet materials were examined in the as-delivered condition as part of this work. The hypothesis for this research proposal is that it is possible to achieve comparable tribological properties in sheet metal forming using water-based lubricants as when using mineral oil-based lubricants. The aim is to optimize a tribological system for water-based lubricants when used as additional lubrication in order to replace mineral oil-based lubricants and, as a result, to shorten the representative process chain by one process step (cleaning). In the course of this work, topographical measurements of the sheet materials were carried out in order to investigate the lubricant holding capacity of the sheet materials. Furthermore, strip drawing tests were performed to determine the friction coefficients of the different lubricant-sheet combinations. The final step was to conduct deep-drawing tests to determine the limits of use of the water-based lubricants by continuously increasing the holding-down force.