Antifriction Performance Research Articles

Comparative Study on the Tribological Performances of Barium Perrhenate, Molybdenum Disulfide, and Calcium Carbonate as Lubricant Additives in a Wide Temperature Range

ABSTRACTBarium perrhenate [Ba(ReO4)2], a compound used as an oil additive, was synthesized via the aqua-solution method. Its tribological properties were examined using the four-ball test and ball-on-disc tribotester in a wide temperature range and compared with those of oil that contained the additive molybdenum disulfide (MoS2) and calcium carbonate (CaCO3) compound. X-ray diffraction analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and differential thermal analysis/thermogravimetry were performed to determine the possible mechanism of the antifriction behavior of the lubricants. Results of the four-ball test showed that all of the additives can improve the extreme pressure property of the base oil and decrease the wear scar diameters of low-carbon steel balls. The results of the ball-on-disc test suggested that the MoS2 additive exhibited better lubrication property than the Ba(ReO4)2 and CaCO3 additives at below 450°C. The CaCO3 additive displayed moderate performance in friction reducing in the high-temperature period. The Ba(ReO4)2 additive exhibited preferable comprehensive antifriction performance in a wide temperature range because of its intrinsic shear-susceptible property and crystalline change with varied temperatures, which could form a protective layer with some native oxides of the disc sample and thus effectively prevented direct contact between rubbing parts. The detailed friction-reducing mechanism of the three additives is also discussed.

Preparation, mechanical and anti-friction performance of MXene/polymer composites

In this study, a Ti3C2 nanomaterial and Ti3C2/UHMWPE (ultrahigh molecular weight polyethylene) nanocomposites were prepared. The morphology, structure and properties of the Ti3C2/UHMWPE nanocomposites were investigated. The results indicate that Ti3C2 nanoparticle can improve the thermal and mechanical properties of UHMWPE. The crystallinity and hardness of the Ti3C2/UHMWPE nanocomposite increase with the content of Ti3C2. The tensile and breaking strengths of the nanocomposites are enhanced with increasing Ti3C2 content and reach maximum values at a mass fraction of 0.75wt.%. The creep performance is enhanced after the addition of Ti3C2 to the matrix. The frictional properties of the Ti3C2/UHMWPE composites were investigated using a pin-on-disc tester. The Ti3C2/UHMWPE composites exhibited a better friction-reducing performance compared with pure UHMWPE. The addition of Ti3C2 can reduce the adhesive wear and plow friction, which results in the worn surfaces of the Ti3C2/UHMWPE composite being smoother than those of pure UHMWPE.

Tribological performance of raw and formulated RBD palm kernel with ZDDP additive

This study compares tribological performance of refined, bleached and deodorized (RBD) palm kernel (PK) as an alternative lubricant. An analysis was made for chemically modified RBD PK with zinc dialkyl dithiophosphate (ZDDP) additive to determine its tribological performance using modified pin-on-disc tribotester. Commercial mineral oil (SAE 40) was used as the benchmark in this study. The conditions for this experiment are sliding speed at 1.5 m/s, a normal load at 9.81 N, weight percentage of ZDDP for 0, 3 and 5%, lubricant quantity of 2.5 ml and test duration of 60 min. The findings revealed that RBD PK oil exhibits better anti-friction and anti-wear performance compared to commercial mineral oil (SAE 40). Besides, coefficient of friction is less dependent on ZDDP concentration, but anti-wear ability is dependent on the ZDDP additive concentration. ZDDP additive acts as a good anti-wear and antioxidant additive in RBD palm kernel.

On a novel solid lubricant technique: A study on the tribological characteristics under dry slide condition

The purpose of this study is to investigate the friction and wear behavior of novel electrostatic micro-solid lubricant (EMSL) bonded molybdenum disulfide (MoS2) coatings on cemented carbide tools under dry slide condition. Pin-on-disc tribological tests between titanium alloy Ti–6Al–4 V and uncoated/coated cemented tungsten carbide–cobalt alloy (WC–Co) were carried out over a range of experimental domain of sliding speeds and normal loads. Specimen wear rate and friction coefficient were investigated. Tribological tests demonstrate that EMSL bonded MoS2 coatings provide excellent anti-friction and reasonable wear performances. The mechanism of enhanced friction and wear behavior with the MoS2 coatings is discussed. This study explores the feasibility of using EMSL coatings onto tribological components and opens a new way to implement bonded MoS2 solid lubricant coatings as a new candidate for tribological operations.

Antifriction performance of Ti-6Al-4V alloy-colored surface by using WEDM-HS press

In this paper, the technology of high-speed wire electrical discharge machining (WEDM-HS) is used for coloring the surface of Ti-6Al-4V alloy, and the antifriction properties of Ti-6Al-4V alloy-colored surface are analyzed. For this paper, we have prepared six kinds of tone by adjusting the electrical discharge processing parameters on the surface of Ti-6Al-4V alloy. Using laser confocal microscopy that observed the microstructure morphology of reaction film after the 1000-h sunlight and water immersion aimed at the coloring mechanism of Ti-6Al-4V alloy surface. RETC micro-friction and wear tester were used to analyze the friction properties of the colored surface with dry friction conditions. The experimental results show that the colored surface after WEDM-HS processing has good stability and durability. Moreover, the average friction coefficient is reduced by 200 % compared with the unprocessed surface, showing excellent antifriction performance.

Enhanced tribological behavior of anodic films containing SiC and PTFE nanoparticles on Ti6Al4V alloy

Abstract Anodic films containing SiC and polytetrafluoroethylene (PTFE) nanoparticles were successfully fabricated on Ti6Al4V alloy by using anodic oxidation method in an environmental friendly electrolyte. The morphology, structure and composition of the films were studied with the scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The results showed that the film contained a layered structure and have a surface full of petaloid bulges, which was totally different from the common anodic oxide film of the porous kind. The tribological properties of the films were investigated with dry friction tests in terms of the friction coefficient, wear rate and the morphology of worn surfaces. The results indicated that the SiC/PTFE composite film exhibited much better anti-wear and anti-friction performances than that of the SiC composite film, the PTFE composite film and the ordinary film without nanoparticles. The SiC/PTFE composite film has friction coefficient of 0.1 and wear rate of 20.133 mg/m, which was decreased respectively by 80% and 44.5% compared with that of the ordinary film. The lubricating mechanisms of the composite film containing SiC and PTFE nanoparticles were discussed. PTFE nanoparticles could lead to the formation of lubricating layer while SiC nanoparticles inside the lubricating layer turned sliding friction to rolling friction.

Fabrication of nano serpentine-potassium acetate intercalation compound and its effect as additive on tribological properties of the fabric self-lubricating liner

The nano Serpentine-Potassium Acetate (Ser-KAc) organic intercalation compound was prepared by treating the nano-serpentine particles with potassium acetate through ultrasonication vibration. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry–thermogravimetry (DSC–TG), and X-ray diffractometry (XRD) were performed to study the effects of the ultrasonication power, ultrasonication time and intercalation temperature on the interlaminar spacing and intercalation rate of the compound. Remarkable intercalation effects were achieved under certain ultrasonication condition. Comparative studies on the tribological properties of the fabric self-lubricating liners with different concentrations of the nano-serpentine or nano Ser-KAc compound additives were conducted. It showed that addition of nano-serpentine or nano Ser-KAc compound improves the wear resistance of the liners to varying degrees but slightly decreases their antifriction performance in an applicative range. In this paper, a model of the unworn fabric self-lubricating liner modified with Ser-KAc compound were developed according to the experimental results. It was found that the liner with 2wt% nano Ser-KAc compound additive exhibited excellent tribological performances.

Preparation and investigation of nano-AlN lubricant with high performance

A new kind of macromolecular coupling agent (LMW-a-PP-g-MAH) of maleic anhydride (MAH) onto low-molecular-weight atactic polypropylene (LMW-a-PP) was synthesized according to molecular design and was used as modifier for surface modification of nano-Aluminum nitride (AlN) by a high-pressure homogenization (HPH) process. IR was conducted to confirm the chemical structure of the step products of LMW-a-PP-g-MAH. The availability as a modifier for surface modification of nano-AlN was distinguished by Fourier transform infrared spectroscopy (FTIR), particle size analysis, transmission electron microscope (TEM), thermogravimetric analysis (TGA), contact angle experiments and the dispersion stability in dimethylbenzene and Greatwall lubrication oil. It can be inferred that the optimal loading is 10 wt. %–12 wt. % of LMW-a-PP-g-MAH to modify nano-AlN particles. Nano-AlN lubricating composite materials (LMW-a-PP-g-MAH-AlN) was used to improve the antifriction performance and the load capability of Greatwall lubrication oil, and maximum non-seizure load (PB) can increase highly from 1000 N to 1490 N when the loading is 0.3 wt. %.

Study of Friction Lubrication Characteristics Research for CVT Fluids in Field Test

By the field test, we carried on the physicochemical tests, the lubrication performance test, the ferrographic analysis and ICP tests for different mileage of CVTF, we also ran the electron microscope analysis of the key components of steel belt of CVT’s friction pair and bevel pulley. The transformation law of CVTF’ lubrication, the inoxidizability, the friction durability friction, the antifriction performance, the attenuation characteristics of functional elements and the abrasion mechanism of Cone wheel and steel belt are investigated.The result showed that there was the presence of extreme pressure film on the surface of friction pair, the physicochemical parameters of CVTF changed very small, the wear metal elements in petrol within 3000km increased slowly.

Research on Graphene Preparation by Liquid Phase Ultrasonic Exfoliation and Antifriction Performance in Water

The different layers of graphene were prepared by liquid ultrasonic direct exfoliation. The dispersion stability of graphene in water under different ultrasonic time, the antifriction Performance, and the elements and morphology of the wear surface are investigated. The wear mechanism of graphene solution was preliminarily discussed. The results indicate that graphene with thickness of 10nm-150nm can be produced by ultrasonic peeling expanded graphite and the dispersion stability of graphene aqueous is best when sonicating for 3h. The antifriction property and wear mechanism of graphene aqueous vary with the graphene content. When graphene content is 0.01wt%, the antifriction performance of graphene aqueous was optimum and its wear mechanism was abrasive wear.

Structure and Mechanical Properties of Titanium-Based Composites and Secondary Films Synthesized during Friction

The structural state and mechanical characteristics of titanium-based composites and secondary lubricating films synthesized on their surface during dry friction are studied. It is found that secondary lubricating films with microheterogeneous and nanocrystalline (grain size <100 nm) structure are synthesized on the materials whose friction coefficient varies between 0.3–0.36 and wear between 1.91–68.3 mg/km at a high slip velocity (15 m/sec) and low pressure (0.8 MPa). These films determine the antifriction properties and performance of the materials. The mechanical characteristics of secondary lubricating films are higher than those of the composites. The antifriction properties can be evaluated from the ratio of the mechanical characteristics of the secondary lubricating films and the starting material: the smaller the ratio, the higher the antifriction properties of the composite.

Study of Anti-Friction Performance of Spherical FeS Nanoparticle

Using face-to-face mode, the antifriction performance of FeS nanoparticle was studied, which prepared by biotechnology as lubricant additive. The results showed that the size about 30-50nm FeS nanoparticle with amorphous state could effectively decrease the friction coefficient of base fluid and the value of friction coefficient reached minimum value when the FeS content was 1%. Moreover, the anti-friction mechanism of FeS nanoparticle was also discussed based on the SEM and EDS results.

Preparation and tribological properties of inclusion complex of β-cyclodextrin/dialkyl pentasulfide as additive in PEG-600 aqueous solution

The inclusion complex of β-cyclodextrin (β-CD) and dialkyl pentasulfide (DPS), in which DPS was incorporated into β-CD cavities, was prepared by a co-precipitation method. The tribological properties of the complex used as lubricant additive in PEG 600 aqueous solution were investigated by a four-ball tester. The complex exhibited better tribological properties than β-CD under different loads, and also showed better anti-friction performance than DPS in the latter half of the test duration. The tribological action mechanism of the complex on a steel surface was studied according to the X-ray photoelectron spectroscopy (XPS) analyses. The β-CD molecules of the complexes were decomposed into various molecular fragments and the DPS molecules were released under the friction condition. It revealed that thiolate and ferrous sulfide (FeS) films formed by DPS played a major role, and iron alkoxide and carbon deposition films formed by the friction fragments of β-CD mainly exhibited anti-friction property on FeS-to-FeS interface. The interactions among different films led to the formation of a mixed boundary lubrication film.

Study on Anti-Friction Performance of Water-Based Flexographic Ink

In order to improve the anti-friction performance of water-based flexographic ink, we made up different kinds of water-base flexographic ink by changing the kinds of film-forming resin or adding different kinds of friction resistant additives, and then evaluated the friction resistant performance of the ink by the rate of density decay. According to analysis the influencing factors of the anti-friction performance of ink, aiming at improving the cohesion of molecular systems and smooth degree of membrane surface, and reducing the friction coefficient as well. The result shows that different molecular structure of film-forming resin ink will cause different cohesion of molecules system in ink, which impacts the ink friction performance. Adding appropriate anti-friction performance additives can improve ink cohesion of molecular system, and improve the ink anti-friction performance as well.

Water-Based Lubrication Preventing Side Grinding Demonstration in Medium-High Water Cut Wells

In order to extend the pump inspection cycle of the seriously-eccentric-wear well, FU-4 water-based lubricant, which can lubricate the boundary and form chemical reaction film and chemical adsorption film on the tubing and pump sucker rods surface, is synthesized by using water-based lubrication theory for reference which has been widely applied in the fields of cutting, grinding and others fields. The chemical reaction film and chemical adsorption film formed by the response activity of phosphorus, nitrogen and fatty acid molecules in the system for the carrier function have good abrasion resistance and anti-friction performance as well as good biodegradability. Adding water-based lubricant of 0.025% to 0.05% in the wells routine maintenance may extend the pump inspection cycle of eccentric-wear side grinding wells. It provides referable technique for managing side grinding wells.

Synthesis and characterizations of graphene–copper nanocomposites and their antifriction application

In this work, a facile one-pot reduction method was used to prepare graphene–copper nanocomposites using graphite oxide and copper sulfate. The nanocomposites were characterized by transmission electron microscope, X-ray diffraction, Raman spectrum, thermal gravimetric analysis, UV–vis analysis and Fourier transform infrared spectrum. It was found that the as-synthesized graphene sheets have few layers and less defects with oxygen functional group on it. The copper nanoparticles with an average diameter of 20nm were uniformly deposited on the graphene sheets. The aggregation of the copper nanoparticles was effectively prevented. The nanocomposites can evenly disperse in base oil. The antifriction performance of the base oil added with GNS–Cu was firstly investigated. It was found that the GNS–Cu nanocomposites as additive in proper ratio showed better antifriction properties with an improvement of the load-carrying capacity by 50%.

A Simulation Study on the Effect of Micro-Textured Tools during Orthogonal Cutting of Titanium Alloy Ti-6Al-4V

The cutting force, cutting temperature and mechanisms are studied by Finite Element Method during the orthogonal metal cutting of Ti-6Al-4V with micro-textured cutting tools. The relation between the texture’s antifriction effect and the parameter of the textures is analyzed. The Derivative-Cutting phenomenon is found when cutting Ti-6Al-4V using textured tools. The mechanisms about how the micro-textured tools change the frictional behavior in the chip-tool interface are explained using Derivative-Cutting characteristic. The antifriction performance of micro-textured cutting tools in the metal cutting process is discussed. The cutting force and cutting temperature is decreased effectively in the cutting simulation with the micro-textured tools manufactured in reasonable parameters.

Tribological properties of magnetic surface lubricated by ferrofluids

In this study, arrayed magnetic films were fabricated on the surface of 45# steel (magnetic). The magnetic field distribution of the micro-magnet arrayed surface was studied. Magnetically controlled suspension – ferrofluids was used as lubricant, which can be adsorbed by magnet. The tribological performance of the arrayed surface affected by the factors of micro-magnet, i.e., area ratio (r), thickness of each magnetic film (t) and magnetized or not, was evaluated using a pin-on-disk test rig. The results suggest that the specimen with 5% area ratio of arrayed magnet is the best of tried ones for low friction at the load-speed conditions. Compared with unmagnetized one, the arrayed surface after magnetizing mainly presents obvious anti-friction properties. The higher magnetic intensity of the surface is, the better anti-friction performance it shows at higher sliding speed condition (0.062–0.188 m/s).

The Antifriction Properties of Ultra-Fine Serpentine Powders as Lube Oil Additive on Iron-Based Friction Pair

X-ray diffraction (XRD) and differential thermal analysis (DTA) as well as heat treating method etc have used to study the material characteristics of ultra-fine serpentine powder and analyze its material science bases for the improvement of tribological intervention behaviors of friction pair surface. The ultra-fine serpentine powders are taken as lube oil additive in present experiment. The friction coefficient is tested on the four-ball and ring-on-block friction pairs under different working conditions, and the surface topography of friction pair are observed and measured with scanning electron microscopy (SEM) and three dimensional white light interfering profilometer. The results indicate that the ultra-fine serpentine powders as lube oil additive can significantly improve the antifriction properties of the lube oil. The content of the added ultra-fine serpentine powders can affect on the antifriction performance of the lube oil.

Study on the Lubrication and Antifriction Mechanism of Low Frictional Self-Lubricating Wear-Resisting Coating

This paper is about the lubricating wear-resisting coating KF301/WS2 and round pit texturing modified coating KF301/WS2 which are prepared by supersonic plasma spraying, laser remelting and surface texturing technology, tribological characteristics of two kinds of coatings are studied under room temperature, according to this, it is discussed for lubrication antifriction mechanism. The research shows: round pit texture has a certain influence on friction factor of coating’s surface and abrasion loss. Friction coefficient of untextured surface is about 0.0138 in the initial stages, while friction coefficient of round pit texture is about 0.01, compared with the former, the latter decreases 27%; when wear time reaches to 1 hour, abrasion loss of untextured surface is 0.0026mg, while abrasion loss of round pit texture is about 0.013mg, compared with the former, the latter decreases 50%. The lubricant antifriction performance of round pit texture is higher than untextured surface, this is because friction coefficient of coating is decreased as the change of the third-body bed, and round pit micro moulding can collect abrasive particle, decreasing the influence of abrasive particle.