Steel Ball Research Articles

Improving accuracy reconstruction of parts through a capability study: A methodology for X-ray Computed Tomography Robotic Cell

Aeronautical performance is enhanced by increasingly complex and lightweight composite parts. The improvement of their manufacturing must ensure the quality measured by Non-Destructive Testing. To evaluate the health of aeronautical parts that are a few meters long, we built a high dimensional robotic cell including two industrial robots positioned on 5-meter-tracks equipped with X-ray Computed Tomography devices. Our main objective is to reconstruct the interior of the parts and detect any anomaly that may have occurred during life cycle or manufacturing (such as porosity or inclusions). In this way, the objective is to present a methodology, firstly, to evaluate the raw process capability and secondly, to assess the improved process capability. The raw process capability uses geometrical identification and we demonstrate that without proper identification, some defects can remain hidden. Three strategies are then developed. The first one involves improving the robot behavior model, which takes into account a thermo-geometrical model, including backlash compensation. Due to possible repositioning problems and to ensure the correct knowledge of the source with respect to the detector, the second strategy involves a real-time test phantom located on the detector named the comb prototype. Finally, a large-sized steel balls phantom is designed to allow a calibration in the full workspace of the robots. This phantom is also used to accurately determine the axis of the rotary horizontal-axis support on which the large parts to be controlled are fixed. We demonstrate that such an architecture, for reconstructing a perfect sphere, leads to an initial mean radius error of 0.05 mm which we improve to 0.016-0.017 mm with our methodology.

Influence of Surface Finish on the Dry Sliding Wear and Electrochemical Corrosion Behaviour of 316L Stainless Steel

316L stainless steel is known for its high corrosion resistance and extensively being used for biomedical implants and for the fabrication of the parts in nuclear reactors, and fuel cells. In the current study, 316L stainless steel samples were grounded using different grades of surface grits (400, 1200, and mirror-finished) by mechanical polishing, and influence of surface finish on the wear and corrosion characteristics was studied. The dry sliding wear experiments were carried out on ball-on-plate setup against hardened steel ball and the corresponding friction curves were obtained and specific wear rates were measured. The wear mechanisms were identified by examining the worn-out surface using scanning electron microscope and Raman spectrometer. It was evident that the formation and removal of iron oxides is the dominant mechanism for material loss from the samples during wear tests. The higher wear resistance of the mirror-finished sample was attributed to the formation of stable chromium oxide layer on the wear track. Potentiodynamic polarization tests were performed on the samples and better corrosion resistance was observed for the mirror-finished sample.

Wear mechanisms of aluminum 5083/6061/7075 with and without T6 treatment

The application of hardened aluminum alloys on the drive elements must be safe and reliable, T6 treatment is often used to improve their mechanical properties and dimensional stability. However, the impact of T6 treatment on operating life is not easy to evaluate. Hence, the effects of T6 treatment on the wear of aluminum 5083/6061/7075 were studied by a steel ball on disk tester. The results showed that T6 treatment tended to reduce the values of the friction coefficient about 9%. Moreover, T6 treatment had no significant effect on the frequency of the change of the friction coefficient of 5083 and 6061, but significantly affected that of 7075. T6 treatment can also reduce the size of wear particles about 16%. Based on the results, the wear mechanisms of aluminum 5083/6061/7075 with and without T6 treatment are described in this paper.

PRODUCTION AND CHARACTERIZATION OF NANO-CACO3 FROM CLAMSHELL (GELOINA SP.) BY TOP-DOWN METHOD

The utilization of nano-CaCO3 is currently growing very fast in various fields. The research aims to produce and analyze the properties of nano-CaCO3 from clamshells (Geloina sp.). The production of nan-CaCO3 was done by the top-down process using high-energy milling. The clamshell (Geloina sp.) is the potential resource of nano-CaCO3. The nano-CaCO3 can be produced by the milling process. The main factor that affected the yield is the number of steel balls, while the speed of rotation and number of cycles have a negative effect. The EDX analysis shows that the nano-CaCO3 has high purity. The nano-CaCO3 from clamshell (Geloine sp.) can be applicated as a drug delivery system and catalyst.

Numerical simulation of linear reciprocating wear mechanism of hybrid aluminum metal matrix composite using finite element method

This work aims to analyze the wear properties of the hybrid aluminum metal matrix composites (HAMMCs) using finite element analysis (FEA). A dry sliding linear reciprocating wear mechanism is analyzed using ANSYS 19.1. Aluminum 7075 alloy and HAMMC reinforced with ZrB2 (1, 3, and 5 wt.%) and fly ash (2 wt.%) is taken as sample material. A steel ball (EN 52100) is utilized as a counterpart in the dry sliding wear properties study. The deformation of the steel ball during the wear process is assumed to be negligible. Under various circumstances, a 3D point-to-surface connection is built to analyze the dry sliding wear process. The wear depth, contact pressure, and wear volume are analyzed using FEA. The analytical results are compared with the experimental results with the help of ANSYS to analyze the process parameters. The ANOVA analysis is employed for optimization, which exhibits that the load had the most significant impact on the material’s wear rate, followed by the material’s composition and temperature. The wear depth, wear rate, and contact pressure at optimum input parameters for the HAMMCs are 0.47 μm, 11.31 × 10−6 mm3 Nm−1, and 0.33 MPa, respectively. The Simulated results support the experimental results, and the average error is 9.82%.

Tribological Properties of Groove-Textured Ti-6Al-4V Alloys with Solid Lubricants in Dry Sliding against GCr15 Steel Balls.

A nanosecond laser is used to fabricate groove-patterned textures on the upper surface of Ti-6Al-4V alloys, and then molybdic sulfide solid lubricants are filled into the grooves. The treated titanium alloy is subjected to friction and wear tests. The tribological performances of Ti-6Al-4V alloys are evaluated, and the wearing mechanism is analyzed. The combination of solid lubricants and surface texturing can effectively reduce the frictional coefficient and reduce the adhesion of Ti-6Al-4V materials on the steel balls for friction. The main wearing mechanism is the adhesive wear of the Ti-6Al-4V alloy and the adhesion of Ti-6Al-4V alloy materials on the surface of the steel balls. During the friction process, solid lubricants are squeezed from the grooves and coated at the friction interface to form a solid lubrication layer. This is the important reason why the combination of surface texturing and solid lubricants can improve the friction properties of titanium alloys effectively. The combination of solid lubricants and laser surface texturing provides an effective alternative way to improve the tribological properties of titanium alloy materials.

A Methodological Approach to Assessing the Tribological Properties of Lubricants Using a Four-Ball Tribometer

Based on the analysis of standards for the testing of lubricants, both liquid and plastic, on a four-ball tribometer, and the analysis of the parameters by which lubricants are evaluated, this paper proposes a methodology and an integral parameter for the estimation of tribological properties. The methodological approach proposed in this paper allows for the integration of a variety of parameters provided in the standards for the testing of lubricants into one indicator. Herein, we show that the developed technique is based on the energy approach and takes into account the specific wear work of the test material (steel balls) in the lubricating medium to be investigated. The results of laboratory tests of a wide range of lubricants are presented: hydraulic fluids, motor and transmission oils of various purposes and classifications. It is shown that the magnitude of the integral parameter can be used to assess the effectiveness of anti-wear and anti-scuff additives in base lubricants, as well as the ranges of their applications. This allows for differentiation and quantitative evaluation of the effectiveness of such additives. The obtained results allow us to state that all tests according to the developed method are reproducible and homogeneous, which is confirmed using the Cochran criterion. The coefficient of variation during testing does not exceed 18%. We show that the presented methodology and the integral parameter can be used in the first stage of the laboratory selection tests of new lubricants and additives of various origins, reducing the costs of their development and implementation.

Influencing Factors on the Fluting in an Axial Ball Bearing at DC Bearing Currents

The effect of variable DC bearing current amplitude, bearing current polarity, mechanical force, rotation speed, bearing temperature, and number of the balls on the fluting in an axial ball bearing type 51208 is investigated under DC currents. The results are obtained from two different test setups with two different lubricants (mineral-oil-based grease and polyglycol oil). The speed varies between 100 rpm and 2000 rpm, the axial bearing force between 200 N and 2400 N, the DC current amplitude between 0.5 A and 20 A, the bearing temperature between 29 °C and 80 °C, the number of steel balls per bearing between 3 and 15, and the test duration between 6 h and 168 h. The results show that with a higher bearing current density and/or a higher bearing speed, a lower bearing force and/or a lower bearing temperature, a bigger number of roller elements, but also at a negative polarity of a DC electric bearing current, the occurring of fluting is more probable and occurs at an earlier stage of operation.

Improved wear resistance of 440C steel ball via ultrasonic strengthening grinding process

The surface wear resistance of 440C steel balls is a critical factor in determining the operational reliability of their products. To address the challenges of enhancing the wear resistance of 440C steel balls, a method of ultrasonic strengthening grinding process (USGP) is introduced. The principle of this method employs ultrasonic waves to drive a mixture consisting of white corundum powder, strengthening liquid, and 440C steel balls. Subsequently, a multi-phase vibration, including steel balls, is generated and impacts a hard steel plate. Meanwhile, the evolutions of surface morphology, microhardness, microstructure, and residual stress of the treated 440C steel balls are revealed. The results demonstrate that the newly proposed USGP method is feasible. Then the deformation principle and microstructure evolution are studied in detail. Finally, the wear resistance of the 440C steel balls treated by USGP is tested. In comparison to the untreated samples, the friction coefficient and wear volumes of the USGP-treated samples were reduced by 38 % and 48.96 %, respectively. The present study highlights the potential of the proposed method for improving the wear resistance of various mechanical components, particularly steel balls.

Nanoparticle formulation for intra-articular treatment of osteoarthritic joints

Based on a proven concept of using nanoparticles to lubricate an articulating interface, we developed a set of formulations to demonstrate the feasibility of using polymeric nanoparticles as physical intervention for early stage osteoarthritis (OA). The biocompatible polymeric nanoparticles (NPs), namely polymethylmethacrylate (PMMA), polycaprolactone (PCL), and polylactic acid (PLA) were accompanied with hyaluronic acid (HA) and surface actives, of which the lubrication effect was examined between a steel ball and a silicone elastomer substrate to replicate the bone-cartilage contact. All three types of polymer nanoparticles were found to reduce the overall Coefficient of Friction (CoF), with PLA NPs being the most effective - providing a reduction up to 24.3%, which suggests that soft (low Young's modulus) nanoparticles are the most efficient frictional additives. Based on the data acquired, it is likely that surface deposited NPs could smooth the solid substrates, hyaluronic acid ensures bulk viscosity, and the surfactant enhances formulation stability. We suggest that surface adsorbed nanoparticles are beneficial in providing interfacial lubrication, which offers insight on the development of early stage intervention strategies for OA.

Microgel-Modified Bilayered Hydrogels Dramatically Boosting Load-Bearing and Lubrication.

Hydrogel-based articular cartilage replacement materials are promising candidates for their potential to provide both high load-bearing capacity and low friction performance, similar to natural cartilage. Nevertheless, the design of these materials presents a significant challenge in reconciling the conflicting demands of the load-bearing capacity and lubrication. Despite extensive research in this area, there is still room for improvement in the creation of hydrogel-based materials that effectively meet these demands. Herein, a facile strategy is provided to realize simultaneously high load-bearing and low friction properties on the proposed hydrogel by modifying the surface of mechanically strong annealled PVA-PAAc hydrogel with a high hydration potential PAAm-co-PAMPS microgel. Consequently, a bilayer hydrogel with a porous surface and a compact substrate has been obtained. Compressive experiments confirmed that the bilayer hydrogel exhibited excellent mechanical strength with a compressive strength of 32.23 MPa at 90% strain. A high load-bearing (applied load up to 30 N), extremely low friction coefficiency (0.01-0.05) and excellent wear resistance (COF low to 0.03 after a 4 h test at 10 N using a steel ball as the contact pair) are successfully achieved. These findings provide new perspectives for the design of articular cartilage materials.

The Impact of Heating Rate on the Kinetics of the Nitriding Process for 52100 Steel.

The aim of this study was to determine the impact of the heating rate of steel balls made of AISI 52100 alloy steel on the kinetics and efficiency of the gas nitriding process when carried out using a chemical reactor with precise thermo-gravimetric measurements, which allowed for changes in sample mass during heating and nitriding to be monitored with an accuracy of 50 µg. In the chemical reactor, the examined alloy steel was subjected to a heating process at the selected nitriding temperature of 590 °C. Two heating variants were used: the first variant relied on heating to the nitriding temperature with different rates-1 °C per minute, 2 °C per minute, 5 °C per minute and 10 °C per minute, respectively-whereas the second variant relied on the fast-25 °C per minute-heating of treated specimens to a temperature of 475 °C, at which, the nitrogenous potential of the atmosphere promotes faster nitrogen diffusion deep into the nitrided substrate, followed by reheating up to the nitriding temperature at different rates: 1 °C per minute, 2 °C per minute, 5 °C per minute, and 10 °C per minute, respectively. To evaluate the impact of heating rate kinetics and effectiveness during nitriding on the obtained surface layer quality, we investigated the phase composition, microhardness distribution, and thickness of the obtained diffusion layers. It was found that heating to a temperature of 475 °C in the nitriding process does not significantly affect the average mass gain of a sample. Above this temperature, within the range of nitriding temperatures, the extension of time increases the sample's mass gain. Simultaneously, it was found that the use of a constant heating rate allows for thicker nitrided layers and a greater sample hardness to be obtained. Dual-stage heating, in turn, is more effective in the context of sample mass gain per time unit.

Dynamic Response Study of Piezoresistive Ti3C2-MXene Sensor for Structural Impacts.

MXenes are a new family of two-dimensional (2D) nanomaterials. They are inorganic compounds of metal carbides/nitrides/carbonitrides. Titanium carbide MXene (Ti3C2-MXene) was the first 2D nanomaterial reported in the MXene family in 2011. Owing to the good physical properties of Ti3C2-MXenes (e.g., conductivity, hydrophilicity, film-forming ability, elasticity) various applications in wearable sensors, energy harvesters, supercapacitors, electronic devices, etc., have been demonstrated. This paper presents the development of a piezoresistive Ti3C2-MXene sensor followed by experimental investigations of its dynamic response behavior when subjected to structural impacts. For the experimental investigations, an inclined ball impact test setup is constructed. Stainless steel balls of different masses and radii are used to apply repeatable impacts on a vertical cantilever plate. The Ti3C2-MXene sensor is attached to this cantilever plate along with a commercial piezoceramic sensor, and their responses for the structural impacts are compared. It is observed from the experiments that the average response times of the Ti3C2-MXene sensor and piezoceramic sensor are 1.28±0.24μs and 31.19±24.61μs, respectively. The fast response time of the Ti3C2-MXene sensor makes it a promising candidate for monitoring structural impacts.

Preparation and Tribological Behavior of Nitrogen-Doped Carbon Nanotube/Ag Nanocomposites as Lubricant Additives

In this study, nitrogen-doped carbon nanotube/Ag nanocomposites (denoted as N-C/Ag) have been synthesized in a urea solution using a hydrothermal method. The carbon nanotubes, AgNO3 solution, urea and poly-dopamine (PDA) served as carbon, silver, nitrogen and carbon sources, respectively. The results show that the diameter of the carbon tubes was about 30 nm, and the Ag nanoparticles, with a diameter of ca. 10 nm, dispersed on the carbon tube surface. The Ag particle size decreased with a lower degree of crystallinity at a high temperature in the presence of urea. The friction and wear behavior of the oil acid (OA) modified N-C/Ag (OAN-C/Ag) as an additive in liquid paraffin (LP) were studied using a four-ball friction and wear tester. The results have shown that the coefficients of friction (COFs) and wear scar diameters (WSDs) of steel balls lubricated with LP-OAN-C/Ag decreased by 27.3% and 25.3%, respectively, relative to pure LP. Tribofilms containing Ag, carbon and nitride were formed on the worn steel ball surfaces. Details, the carbon, Fe2O3, azides and nitride, Ag and alloy and other compounds on the wear scars may improve tribological properties. The synergistic effect of carbon, Ag and urea plays a critical role during sliding.

Effect of natural aging on mechanical properties and corrosion behavior of 2219 aluminum alloy cold sprayed coatings

The study delves into examining how the natural aging (NA) process influences the mechanical properties and corrosion behavior of cold spray (CS) coatings. The results reveal several key insights: the consolidation behavior of auxiliary steel balls weakens, leading to a transition in the microhardness distribution of the coating from a “stepped” pattern to a more “uniform” pattern, with an average microhardness value fluctuating around 120 HV. Tensile strength experienced a reduction of 4.3 %, and elongation increased by 13.4 %. Electrochemical and peeling corrosion experiments revealed that, after aging, the coating still exhibited no signs of peeling. The corrosion resistance of the coating remains significantly superior to that of the base material (BM). Remarkably, the CS coating continues to provide effective protective functionality for joints even after undergoing 1825 days of NA.

Ultra-low wear in multifunctional Ti3C2Tx/PI composite films induced by tribo-chemistry mechanism

Ti3C2Tx MXene was cooperated with polyimide (PI) to improve the wear resistance of the PI matrix under complex working conditions. Compared to the pristine PI, the Ti3C2Tx/PI composites have excellent frictional properties, specifically, the coefficient of friction is 0.32 and the wear rate is 0.62 × 10−5 mm3/(N·m). The composites formed a transfer film on the contact surface during the friction process, and the transfer film prevents direct contact between tribo-couples. The results studied by Raman and XPS showed that the transfer film contains TiO2 that is derived from oxidized Ti3C2Tx. Moreover, the tribological mechanism has been summarized as two aspects: On one hand, the relative sliding of the Ti3C2Tx lamellae transfers the sliding stress. On the other hand, a transfer film is created between Ti3C2Tx/PI composites and steel ball during friction that prevents further wear of the material. All in all, two-dimensional MXene can effectively improve the wear resistance of the polymer matrix and has the potential to be used in friction-protective layers under complex working conditions.

Experiment and simulation analysis of tribological and dynamic characteristics in aeroengine hybrid ceramic bearing

Purpose This paper aims to research the tribological and dynamic characteristics of aeroengine hybrid ceramic bearings through wear experiments and simulation analysis. Design/methodology/approach First, the authors carried out wear experiments on Si3N4–GCr15 and GCr15–GCr15 friction pairs through the ball-disc wear test rig to explore the tribological properties of their materials. Second, using ANSYS/LS-DYNA simulation software, the dynamic simulation analysis of hybrid bearings was carried out under certain working conditions, and the dynamic contact stress of all-steel bearings of the same size was simulated and compared. Finally, the change of the maximum contact stress of the main bearing under the change of load and rotation speed was studied. Findings The results show that the Si3N4–GCr15 pair has better tribological performance. At the same time, under the conditions of high speed and heavy load, the simulation analysis shows that the contact stress between the ceramic ball and the raceway of the ring is smaller than the steel ball. That is, hybrid bearings have better transient mechanical properties than all-steel bearings. With the speed increasing to 12,000 r/min, the maximum stress point will shift in the inner and outer rings. Originality/value In this study, the tribological and transient mechanical properties of Si3N4 material were comprehensively analyzed through wear experiments and dynamic simulation analysis, which provided a reference for the design of hybrid bearings for next-generation aeroengines.

TRIBOLOGICAL WEAR ANALYSIS OF Ti-Al COMPOSITE COATINGS APPLIED WITH THE COLD SPRAY METHOD

The possibility of using the low-pressure cold gas spraying (LPCS) method to create composite coatings hasbeen known and used for a long time. This method makes it possible to create coatings from physically andchemically different powders and to regenerate components damaged during operation. Composite coatingsof titanium and aluminium at different weight concentrations were selected for the study. The research wasconducted to optimise the influence of the chemical composition of the composite coatings on their tribologicalproperties. This paper presents the results of tribological wear testing of composite coatings applied using thelow-pressure cold gas spray (LPCS) method. Wear resistance tests were performed using the ball-on-platemethod in reciprocating motion using a steel ball. Tribological testing of the coatings included determiningthe effect of contact force on wear and the value of the kinetic coefficient of friction of the friction pairs tested.The study determined the optimum chemical composition of the Ti-Al composite coatings to improve wearproperties.

Plasma Coatings Based on Self-Fluxing NiCrBSi Alloy with Improved Wear Resistance Properties

The structure and properties of plasma coatings sprayed with a composite material based on a self-fluxing NiCrBSi alloy (PG-10N-01 alloy) modified with a composite material obtained by self-propagating high-temperature synthesis were studied. Titanium powders, carbon black, aluminum, iron oxide, PT-NA-01 thermosetting powder and PGOSA-0 refractory clay were used as the initial components of modified with a composite material. Mixing and mechanical activation of the initial powders was carried out in a BM-1 ball mill for 15 minutes at 130 rpm in a ratio of 1 to 40 of the mass of the charge to the mass of the falling bodies (steel balls with a diameter of 6 mm). Initiation of the self-propagating high-temperature synthesis was carried out using a special device by introducing a heated nichrome spiral. The process of coatings spraying was performed on the MPN-004 microplasma spraying unit at a current of 45 A, a voltage of 30 V with a distance of 100 mm on samples made of 65G steel with a thickness of 3 mm. Argon was used as a plasma-forming and shielding gas. In order to substantiate the feasibility of the self-propagating high-temperature synthesis, a part of the samples was sprayed with a self-fluxing alloy PG-10N-01 with the addition of a mechanical mixture of starting powders. It was established that as a result of plasma spraying of the PG-10N-01 alloy and the composite material of the modified with a composite material + PG-10N-01 composition, coatings with a dense and multiphase structure are formed. The microstructure of the PG-10N-01 alloy coating consists of a solid solution based on nickel (γ-Ni) with inclusions of nickel borides Ni3B and chromium carbides Cr3C2. When adding modified with a composite material in a nickel-based solid solution, in addition to the phases indicated above, borides of titanium TiB2, carbides of titanium TiC and silicon SiC were detected. Their presence leads to an increase in the microhardness of such coatings and their greater wear resistance under conditions of abrasive wear in comparison with the spraying coating of the PG-10H-01 alloy.

Проектирование технологии обработки в гранулированных средах в условиях цифрового производства

The problem of mechanical technology design for machining parts in granulated media in the conditions of digital produc-tion is viewed. The peculiarities of part process in abrasive media and with steel balls (finish- machining and strengthening treatment techniques) are shown. Dependences for determining the parameters of a single interaction of a medium particle with the surface of a part during processing in granulated media are obtained. Dependences for depth maximizing in cases of particle penetration into the surface of the machined part, the parameters of a single trace, surface roughness, processing time are found. For finish- machining and strengthening treatment techniques for granulated working media, dependences for determining the depth of the hardened layer and the degree of deformation are also obtained. The obtained theoretical dependences have been tested for adequacy through drawing an analogy with the results of experimental studies. During the research, it was found that the developed system of models does not take into account the peculiarities of various processing methods and their dynamics, and shape of the particles of the medium. To account all these parameters, the Rocky DEM ap-plication software package is used. The package allows modeling the processing chamber, the dynamic parameters of the machining process, the number of particles in the working space according to their mass, the shape and dimensions of the particles, the mass and shape of the machined part and its location in the processing chamber, the material of the machined part, the ratio of the mass of the part and the mass of the abrasive medium, some physical properties of the material of the processed part, slip coefficient of the abrasive medium on the part surface, process liquid properties and other parameters. The package made it possible to refine theoretical models and obtain results closer to production conditions. Based on the research carried out and being aimed at their introduction into modern digital production, the design technique of techno-logical processes has been developed and a software product has been proposed allowing to select possible working meth-ods in granulated media (in order of preference) according to the characteristics of the part, and to determine the technolog-ical modes for each of them and characteristics of working environments.