Steel Ball Research Articles

An Evaluation of the Wear Resistance of Electroplated Nickel Coatings Composited with 2,2,6,6-Tetramethylpiperidine 1-oxyl-Oxidized Cellulose Nanofibers.

In this study, the wear resistance of nickel (Ni)-cellulose nanofiber (CNF) composite electroplated films on steel plates (JIS SPCC, cold-rolled steel) was evaluated, including their surface and microstructural properties. In the CNF sample, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-oxidized CNF was used. As a result of the ball-on-disk abrasion test, in which steel (SUJ2) balls were used as the counterpart material, the plated film obtained with the addition of 1 g/L of CNF to the plating solution showed the highest wear resistance in this study. Compared to the conventional Ni-plated film without CNF, the abrasion loss volume on the plated side was reduced by approximately 79%, and that on the ball side was reduced remarkably by 94%. A microstructural analysis of the abrasion scars showed areas where co-deposited CNFs were stretched in the direction of abrasion, suggesting that the wear reduction effect was caused by sliding between the individual CNFs within the aggregates. Moreover, the hardness of the plated film increased when the Ni crystallite size became finer. It was confirmed that the co-deposition of fine CNFs is effective in improving hardness, whereas the co-deposition of a certain degree of aggregated CNFs is effective in exhibiting the wear reduction effect.

Monitoring Lubrication and Wear in-situ by triboelectrification Under Vacuum Conditions

Maintaining the condition of the friction pair is an important measure to reduce mechanical failure. This paper integrates a vacuum elastohydrodynamic oil film measurement device and a current amplifier to simultaneously observe the optical interference image, friction coefficient and triboelectric signal during the friction process. In a high vacuum environment, the discharge phenomenon of steel balls corresponds to the time when the friction pair wears. Changes in the friction state in high vacuum environments have a significant impact on triboelectricity. Based on the relationship between the two, a sensor for real-time monitoring of the friction and wear status of the friction pair is designed, which provides a reliable real-time monitoring method for friction pair monitoring in vacuum machinery.

Evaluation of tribological efficacy and EP lubricity properties of gear oil (EP90) energized with molybdenum disulfide (MoS2) nano-additives

The practice of employing efficient lubricants involving functional additives has become imperative in order to enhance engine efficiency, to say the least. The span of an engine’s life can be greatly enhanced by gear oil’s tribological and thermo-physical properties. Addressing the tribological management of gearbox components within the mechanical sector is a dire necessity. In a quest for exceptional nanolubricants with improved serviceability, present manuscript deals with the dispersion of metallic-sulphide nano dispersants in gear oil lubricant. Nanolubricants were prepared by dispersing molybdenum disulfide nanoparticles (MoS2 Nps) in gear oil with varying concentrations of 0.1%, 0.3%, and 0.5% by volume (v/v). Then nanolubricants’ thermo-physical properties were assessed and contrasted with those of plain gear oil. This was followed by the measurement of the tribological and extreme pressure properties of the nanolubricant samples on a four-ball tester. According to the findings, as compared to gear oil, the prepared nanolubricant yielded a maximum reduction of 9.21% and 9.38% in coefficient of friction and an average wear scar diameter, respectively. A maximum augmentation of 12% in weld load was obtained with 0.3% nanolubricant sample. The wear scar on the steel balls was examined using field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscope (EDS). The investigations revealed the presence of ball bearing and surface polishing effects as dominant lubricating mechanisms, which potentially contribute to the enhanced tribological properties of the oil. Hence, adding MoS2 Nps in gear oil may solve many engineering problems related to the lubricity of the base oil.

TiO2 and CeO2 nanoparticles as lithium complex grease additives for enhanced lubricity

PurposeThis paper aims to improve the tribological properties of lithium complex greases using nanoparticles to investigate the tribological behavior of single additives (nano-TiO2 or nano-CeO2) and composite additives (nano-TiO2–CeO2) in lithium complex greases and to analyze the mechanism of their influence using a variety of characterization tools.Design/methodology/approachThe morphology and microstructure of the nanoparticles were characterized by scanning electron microscopy and an X-ray diffractometer. The tribological properties of different nanoparticles, as well as compounded nanoparticles as greases, were evaluated. Average friction coefficients and wear diameters were analyzed. Scanning electron microscopy and three-dimensional topography were used to analyze the surface topography of worn steel balls. The elements present on the worn steel balls’ surface were analyzed using energy-dispersive spectroscopy and X-ray photoelectron spectroscopy.FindingsThe results showed that the coefficient of friction (COF) of grease with all three nanoparticles added was low. The grease-containing composite nanoparticles exhibited a lower COF and superior anti-wear properties. The sample displayed its optimal tribological performance when the ratio of TiO2 to CeO2 was 6:4, resulting in a 30.5% reduction in the COF and a 29.2% decrease in wear spot diameter compared to the original grease. Additionally, the roughness of the worn spot surface and the maximum depth of the wear mark were significantly reduced.Originality/valueThe main innovation of this study is the first mixing of nano-TiO2 and nano-CeO2 with different sizes and properties as compound lithium grease additives to significantly enhance the anti-wear and friction reduction properties of this grease. The results of friction experiments with a single additive are used as a basis to explore the synergistic lubrication mechanism of the compounded nanoparticles. This innovative approach provides a new reference and direction for future research and development of grease additives.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2023-0291/

Corrosion resistance and tribological behavior of FeCoCrNi@GO/Ni high entropy alloy-based composite coatings prepared by electrodeposition

The preparation of high entropy alloy (HEA) coatings onto a stainless-steel substrate is crucial to pursue improved corrosion and wear resistance but are still challenging. Herein, FeCoCrNi@GO/Ni coatings are innovatively cross-integrated with stainless steel by introducing a nickel transition layer to break through the “bottleneck” of stainless steel. Meanwhile, variation of the coating corrosion resistance in 3.5 wt% NaCl solution and tribological behavior against GCr15 steel balls was also deeply explored. The addition of graphene oxide (GO) delayed the movement of corrosive medium and improved the corrosion resistance. Interestingly, the coatings with low GO content and high GO content show different wear mechanisms respectively, and the lower GO content is conducive to the formation of oxidized lubrication layer, thus protecting the substrate from severe friction and wear. However, the high content of GO coating will cause damage and spalling of oxide layer and GO, and the wear mechanism changes from oxidative wear to the co-wear of oxidative wear and abrasive wear. This work will provide a novel idea for the development of HEA coatings in the future.

Numerical and experimental study for process improvement of cross-wedge rolling of bearing steel balls

The uniaxial compression experiments were conducted on GCr15 bearing steel to obtain the flow stress curves under hot deformation conditions. Based on the results of uniaxial compression experiments, finite element modeling was conducted on the cross wedge rolling (CWR) of GCr15 bearing steel balls, and numerical simulation was conducted using Simufact Forming 16.0. The results show that the distribution of effective strain of existing CWR steel balls is uneven, which may lead to uneven quality of steel balls. In addition, the three principal stresses at the center of the steel balls are all tensile stresses, and the effective stress at the center of the middle ball is relatively large, which can easily induce central defects. Moreover, different diameter billets were used for steel balls rolling experiments. It can be seen that when the die cavity is underfilled with billet, the rolled steel balls have no central defects. When the die cavity is fulfilled with billet, there is central piercing appearing at the middle ball, while the side balls have no obvious central defects. Finally, the paper proposes the method of even numbered ball rolling (ENBR) which starts from the middle connector to improve the CWR process of steel balls.

Vertical magnification correction in vertical dual-exposure panoramic radiography.

To clarify the magnification error caused by the degree of tilt of the incisor and the elevation of the X-ray focus position, and the verification effect of magnification correction when performing vertical dual-exposure panoramic radiography. Panoramic radiographic images of a phantom embedding 26 steel balls were taken at different heights (0, 5, 10, 15, and 20 mm) and tilt angles (0°, 10°, 20°, and 30°) to evaluate vertical magnification in each condition. Error and correlation coefficients in the vertical magnifications were calculated between the measured and theoretical magnification values. The more the steel ball phantom was tilted, the more the images of the uppermost steel balls were laterally stretched. In the vertical direction, image magnification also influenced the tilt angle of the object in the incisal region. The range of error in vertical magnification was -0.35-0.30%. The Spearman's rank correlation coefficient between the measured and theoretical magnification value was 0.983. Vertical magnification correction has the potential to improve image quality when merging panoramic radiographs in vertical dual-exposure panoramic radiography.

Experimental study on thermal and mechanical properties of concrete block of phase change pile foundation and simulation study on performance of phase change energy pile

Phase change materials are incorporated into concrete to create phase change pile storage concrete, significantly enhancing the heat transfer efficiency of energy piles. However, adding these aggregates reduces concrete strength. This research examines how different proportions of steel balls, silicon carbide powder, and steel fibers affect the thermal and mechanical properties of pile foundation concrete. An orthogonal test under compressive design strength shows that a mix of 9% silicon carbide powder, 0.7% steel fiber, and 15% steel balls increases thermal conductivity by 25.3%. Numerical simulations with this optimized ratio indicate a 21% increase in heat transfer per unit depth compared to standard energy piles. The phase change energy pile notably lessens thermal effects on soil; within 30 days of operation, its thermal influence radius decreased by 11.9%. Furthermore, maximum reductions in side friction, pile side stress, and displacement were recorded at 95.9%, 59.1%, and 80.3%, respectively- demonstrating excellent structural stability.

Functionality integration in stereolithography 3D printed microfluidics using a "print-pause-print" strategy.

Stereolithography 3D printing, although an increasingly used fabrication method for microfluidic chips, has the main disadvantage of producing monolithic chips in a single material. We propose to incorporate during printing various objects using a "print-pause-print" strategy. Here, we demonstrate that this novel approach can be used to incorporate glass slides, hydrosoluble films, paper pads, steel balls, elastic or nanoporous membranes and silicon-based microdevices, in order to add microfluidic functionalities as diverse as valves, fluidic diodes, shallow chambers, imaging windows for bacteria tracking, storage of reagents, blue energy harvesting or filters for cell capture and culture.

CHARACTERISTICS OF FLOW REGIMES IN SPIRAL PACKED BEDS WITH SPHERES

Packed beds are used in many fields such as heat exchangers, cooling systems, filtration, and reactors. Porous media can be used in order to enhance the heat transfer between the solid and the fluid, but it also creates higher pressure drops for the same flow rate. The flow regime significantly affects the heat transfer and pumping power of the fluid. It is known that when the channel is either curved or packed separately, the pressure drop increases. There are many studies on pressure drop and flow regimes in porous media or curvilinear channels. However, there are not many studies on pressure drop and flow regimes in a curvilinear packed bed. In this work, the pressure drops and flow regimes were determined when the channel is both curved and porous media. The packed beds were formed with two different radii of curvature, 71 and 171 mm in diameter, and were filled from steel balls with different particle diameters of 2.00, 2.38, and 3.17 mm. The pressure drop in these spiral packed beds was measured experimentally and flow regimes were determined for each test chamber and ball diameter. In each flow regime, permeabilities, Forchheimer coefficients, and the coefficients corresponding to Ergun constants were calculated. The effect of the curvature ratio was interpreted as the difference from the straight packed beds. Determining the flow regime ranges of curved packed beds can help to better interpret the heat transfer and pumping power of the fluid in these regimes.

Network interactions simultaneously enhance stiffness and lubricity of triple-network hydrogels.

Synthetic hydrogels displaying cartilage-mimetic bulk and surface properties may serve as cartilage substitutes. Multi-network, electrostatic hydrogels that leverage intra- and inter-network repulsive and attractive forces represent a promising approach. Herein, triple network (TN) hydrogels were prepared to obtain a combination of desired characteristics (i.e., hydration, stiffness, shear stress, and friction properties). The TN hydrogels were comprised of a negatively charged 1st network and a neutral 2nd network possessing hydrophobic associations. Presumed to significantly influence surface properties, the 3rd network charge was systematically varied as cationic, anionic, and zwitterionic. A double-network (DN) hydrogel, comprised of the same 1st and 2nd network as for the TN hydrogels, was included as a control as well as native cartilage specimens. Micro-indentation was performed with a steel ball, yielding stiffness values as well as the contact area during sliding. The lubrication in both deionized (DI) water and fetal bovine serum (FBS) was evaluated with the micro-indenter wherein the stage reciprocated in a range of speeds. All the TN hydrogels exhibited greater Youngs modulus than the DN hydrogel control. The TN bearing a cationic 3rd network exhibited an exceptionally high Youngs modulus of ≈1.4 MPa, which was even higher than that of the cartilage samples. In both DI water and FBS, for most testing speeds, the TN hydrogels exhibited lower friction coefficient (COF) values and lower shear stresses than DN hydrogel as well as the native cartilage specimens.

Демонстрационный эксперимент при изучении распределения Больцмана

We offer a technique and methodology for using a lecture experiment to measure the dependence of particle concentration on height. Steel balls in a vertical cell with glass walls play the role of particles participating in the chaotic movement, which is initiated by the vibrating bottom of the cuvette. Video recording of the cuvette with moving balls is carried out using a standard web camera. The developed real-time image processing program determines the vertical coordinates of particles, performs averaging over several frames, and plots graphs of the measured dependence of the average particle concentration on height and functions that approximate the experimental curves.

Research on the Tribological Properties of Layered Kaolin Lubricant Additives

Lubricant additives are the main means to improve the performance of lubricants. In this article, green and inexpensive layered kaolin were selected as lubricant additives, and the effects of the type of modifier, concentration, particle size of kaolin additives, and working temperatures on the tribological performance of lubricants were investigated. The results showed that the Span80 modifier can effectively improve the dispersibility and friction reduction effects of kaolin oil samples. Compared with kaolin oil samples without the modifier, the modified kaolin oil can reduce the friction coefficient by 40.9% and the wear spot diameter of the steel balls by 43.8%. The layered kaolin additive can significantly reduce the friction coefficient and wear of steel balls in lubrication, and the friction coefficient showed a trend of decreasing and then increasing with increasing kaolin additive concentration and particle size. The optimal added concentration and particle size of kaolin are 5 wt% and 2 μm, respectively, which can reduce the friction coefficient by 41.9% and 65.63% and the wear spot diameter by 12.31% and 50.72%, respectively, compared with the base oil. At five temperatures, compared with the base oil, the kaolin oil samples all showed better friction reduction and anti-wear properties. The micro and nano size of the kaolin additive, the layered structure, and the chemically reactive film generated on the surface are the main reasons for its good lubrication performance.

EXPERIMENTAL AND THEORETICAL STUDY OF SPACE DEBRIS IMPACTS ON SHIELDED TARGETS

A comprehensive study is reported on highand hypervelocity impacts of a steel ball simulating a space debris particle on shielded targets. Experimental studies of high-velocity impact of a steel ball were performed in the velocity range up to 2500 m/s. The obtained data were used to verify the mathematical model and numerical algorithm. Numerical modeling of space debris impact on a shielded target was carried out in the impact velocity range of 1400-7000 m/s using the finite element method implemented in the original EFES software package. The proposed failure algorithm can describe the fragmentation of the material and the formation of new contact boundaries without computational mesh distortion. The specific features of shock wave processes and the destruction of the target and impactor at different impact velocities were investigated.

Numerical study of effect porous media on heat transfer in a horizontal annular tube

In the current study, to enhance the characteristics and forced convection performance in the horizontal annular in the case of the presence of porous material and without porous material, energy analyses were performed. Many types of porous material, porosities, and diameters were used. Computational fluid dynamics was used to simulate an annuli tube in case of the presence of porous material and without porous material by utilization of ANSYS FLUENT software 17.2. The working fluid utilized was water with Reynolds number from 100-500 and constant wall heat flux at 150 kW/m2. Two types of porous media glass and steel balls, two different porosities (0.6 and 0.7), and two different porous material diameters (12 and 24mm) were utilized. Investigations occurred under the study state for studying heat transfer properties and flow of fluid in the annuli tube. The energy analysis outcomes showed that there is a relationship between Nu and Reynolds number. The highest enhancement of Nu number happened at 12mm diameter and 0.6 porosity for bolls of glass and 0.7 for bolls of steel. The pressure drop rising occurs with the rising of Re for all cases and the diameter of 12mm gives the maximum pressure drop for both steel and glass pellets and the uppermost pressure drop occurs at a porosity of 0.6. As compared with those in the annulus in the absence of a glass sphere as porous material at the same ball volumes.

Wear Scar Characteristics of Thermal Power Plant Waste Reinforced Nickel Matrix Composite Coatings

This research delves into the distinct wear scar properties exhibited by pure nickel and nickel composite coatings with varying concentrations of fly ash when sliding against a stainless steel ball on an aluminium alloy 6061 (AA6061) substrate. The composite coatings were formulated from a modified nickel Watt's bath using an electrodeposition technique, involving a 1-hour process at 40°C and a current density of 5 A/dm². Through experimentation utilizing a high-frequency reciprocating rig (HFRR) tester, the resulting composite coatings underwent assessment, capturing the features of the scar surfaces. Notably, the Ni-FA (nickel-fly ash) composite coating, comprising 90 g/l of fly ash, demonstrated notably enhanced wear resistance in contrast to both the pure nickel coating and the Ni-FA composite coatings with lower fly ash concentrations. The disparities in morphology between the pure nickel and Ni-FA composite coatings were discernible through scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS), and analysis of surface roughness on the wear scars. These distinctions can be attributed to the varying impacts of fly ash concentration on the wear scar characteristics.

The Influence of the Geometry of Movement during the Friction Process on the Change in the Tribological Properties of 30CrNiMo8 Steel in Contact with a G40 Steel Ball.

Experiments with changes in motion geometry can provide valuable data for engineering and development purposes, allowing a better understanding of the influence of tribological factors on the performance and service life of joints. The presented subject article focused on the experimental investigation of the influence of the geometry of the movement of the friction process on the change in the tribological properties of 30CrNiMo8 steel. The friction process was carried out without the use of a lubricant in contact with a steel ball of G40 material with a diameter of 4.76 mm. The steel ball performed two types of movement on the surface of the experimental material. The first method used was ball on disc, in which the ball moved reciprocally in an oval direction at an angle of 180° on a circumferential length of 35 mm at a speed of 5 mm/s. The second method consists of the same input parameters of the measurement, with the difference that the path along which the ball moved had a linear character. The load during the experiment was set at a constant value of 50 N with 1000 repetitions. The results show that with the ball on disc method, there was an increase in wear by 147% compared to the linear test method, which was approximately a coefficient of increase in wear of 2.468. EDS analysis pointed to the occurrence of oxidative wear that affected the resulting COF values, which were lower by 8% when using the ball on disc method due to a more uniform distribution of O and C on the surface of the friction groove where these elements acted as solid microlubricants. With the ball on disc method, defects in the form of microcracks occurred, which affected the reduction in the values of the depth of the affected area of microhardness.

The Analysis of Vibration Resistance of the Shape and Braided Laminated Manufactured Structure Using Taguchi Method

In this study, the L934 orthogonal table of the Taguchi method is used as a systematic parameter analysis. A rapid prototyping machine (RPM, manufactured by the research team) and fused deposition modeling (FDM) are used to make anti-vibration test specimens and to analyze the effect of different process parameters, such as weaving and shaping, on vibration resistance. Hopefully, various application fields will be extended via the deposition method. The impact test is executed by dropping a steel ball onto each test piece which is connected to an accelerometer and a PW700 spectrometer for extracting the frequency response during the impact. The vibration performance under different process parameters is analyzed. Several parameters that may affect anti-vibration performance are selected under the existing process, namely weaving method (A), deposition thickness (B), weaving density (C) and cross weaving per n-layer (D). The policy is to evaluate the required time period to restore to the steady state after impact. Hence, the shorter the convergence time is, the better the specimen resists the vibration. The experimental results show that the build-up layer thickness and the weaving density are the main control factors that affect the anti-vibration ability most. The process parameter A3B1C1D2 obtains the best vibration resistance performance.

Structure and tribological properties of multiphase carbon coatings fabricated by multi-arc ion plating

Carbon coating with excellent wear resistance will play a significant role in protecting metal materials, especially in piston rings. In this work, a series of multiphase carbon coatings were fabricated by multi-arc ion plating under different bias voltages ranging from 0 to 160 V. The microstructures were investigated by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Raman Spectroscopy and X-ray Photoelectron Spectrometry (XPS). The mechanical properties and tribological performances were measured by nanoindentation, scratching tester and reciprocating tribometer. The results demonstrated that the multiphase carbon coatings mainly compose different phases, including amorphous carbon, fullerene-like carbon, nanographite, nanodiamond and C60. The sp2 hybrid bond existed in the form of multi-bent carbon rings and increased from 46.82 % to 52.01 % with the increase of bias voltage. The content of seven-membered carbon rings (7A1) increased first and then decreased, with the highest value of 18.05 %. The hardness values of the coatings ranged from 18.33 ± 3.55 GPa to 33.88 ± 2.26 GPa. When Vickers indenter was pressed into the coating under high load, the coating exhibited good load strength and toughness. Under the load of 10 N, the friction coefficient between the coating and Φ3 mm 316 stainless steel (SS) balls in fresh 5 W-30 oil was about 0.13. In the degraded oil, the highest friction coefficient was 0.20, and the lowest was 0.11. The grinding ball's surface looked to have sustained severe damage, but there was no visible damage to the coating structure at the worn tracks. There was no significant difference in the coating surface profile curves before and after rubbing exhibiting super wear resistance of coatings.

Glycerol aqueous solutions for the enhanced tribological behaviour of polymer composites sliding against steel

In this study the potential benefits of using glycerol solutions containing 20%, 40%, 60%, or 80% water as environmentally adapted lubricants (EALs) on the tribological properties of polyoxymethylene (POM) and polyetheretherketone (PEEK) polymer composites was examined. For comparative purposes, pure glycerol and water were used. The friction and wear mechanisms of three different polymer composites were analysed: PEEK CF30 (PEEK reinforced with 30% carbon fibre), PEEK MOD (PEEK reinforced with 10% carbon fibre, 10% graphite and 10% polytetrafluoroethylene), and POM CF30 (POM with 30% carbon fibre). The tribological measurements were performed under reciprocating sliding conditions with a steel ball on a polymer plate. For all the composites in glycerol and in glycerol with up to 40% water the coefficient of friction was low (∼ 0.02). The specific wear rate was also low and about the same for all polymers, of the order of 10−8 mm3/(Nm). However, at higher water contents (80% of water and pure water) both the coefficient of friction and the specific wear rate increased and a transfer film formed on the steel counterparts. In the lubricant with a higher water content the PEEK CF30 showed the lowest specific wear-rate increase (24 times in the lubricant with 80% water), followed by the POM CF30 (52 times in the lubricant with 80% water). At higher water contents the POM CF30 showed the smallest increase in the coefficient of friction (3.6 times in the lubricant with 80% water), an increase up to two times less than for the PEEK polymers.