Wear Test Rig Research Articles

The Exposure Height of Silicon Particle with Round Edges Effect on the Tribological Property of Al-Si Alloy Cylinder Liner

In order to improve the wear resistance of Al-Si alloy cylinder liners, surface treatment is usually used. The Al-Si alloy cylinder liner samples were prepared by mechanical grinding and laser finishing. The mechanical grinding samples were carried out by the independent design and development of a grinding machine. The laser finishing samples were laser-heated by a CO2 continuous transverse-flow laser. Both of the two surface treatments could provide the surfaces of protruding silicon particles with round edges to improve the wear resistance. However, in the exposure height of silicon particles with round edges, the study was lacking. The exposure height of silicon particles is important to the tribological properties of the Al-Si alloy cylinder liner, and should be analyzed in detail. The wear tests were completed by a contraposition reciprocating wear test rig under lubrication. It was found that when the silicon particles were exposed on the surface of the Al-Si alloy cylinder liner sample by 1.2 μm, the mechanical grinding samples and laser finishing samples all exhibited minimum friction coefficients and weight losses. This paper confirms that a suitable exposure height of silicon particles would reduce the probability of adhesion wear and abrasive wear of Al-Si alloy cylinder liners and increase the lubrication. It presents an excellent tribological property. However, when the exposure height of silicon particles is too high, the silicon particle is easily prone to plastic deformation or even falls off during the friction process due to the high stress and larger plastic contact index.

Analysis of abrasive impact wear of the Mn8/SS400 bimetal composite using a newly designed wear testing rig

In this study, the abrasive impact wear behaviour of a bimetal composite made of medium manganese steels (MMSs) and low carbon steels (LCSs), i.e., the Mn8/SS400 bimetal composite, was investigated using a newly designed wear-testing rig. The need for a new rig arose from the difficulty in replicating real-world wear conditions. Our rig allows for precise control and measurement of wear, simulating harsh environments more accurately than other wear-testing rigs. The bimetal composite Mn8/SS400 demonstrated superior wear resistance, showing an improvement of up to 2.8 times compared to benchmark steels, attributed to its enhanced work hardening sensitivity. Scanning electron microscopy (SEM), X-ray diffractometer (XRD), and electron backscatter diffraction (EBSD) analyses were employed to elucidate the wear mechanisms. After 300 h of abrasive impact wear, the subsurface microhardness of Mn8 reached 601.31 HV, significantly higher than that of the matrix hardness of 292.24 HV, indicating a substantial work hardening effect. The wear mechanism of the Mn8/SS400 bimetal composite was found to be a synergistic effect of grain refinement strengthening, dislocation strengthening, and twin strengthening. Initially, twin strengthening was the dominant mechanism up to 200 h of wear testing. However, after 300 h, contributions from all three mechanisms became increasingly significant, enhancing the overall wear resistance of the composite.

Development of a Cost-Effective Twin-Disc Test Rig for Railway Wear Simulation

Maintenance due to the replacement of damaged wheels and rails due to rolling contact fatigue (RCF) and wear has been found to be the major problem to rail operating companies. This problem tends to lead to unavailability of railway networks. To solve this problem, costly wear simulators are developed to predict the wear behaviour of the rails and wheels to improve the preventive maintenance in pursuit of operational efficiency. Therefore, more studies that simulate a combination of rolling and sliding wear, together with RCF, are required, specifically for the Southern African, where good and cost-effective rail wear simulators are not readily available. The problem with wear and RCF simulators is high production costs, so this work aims to solve this problem by developing a cost-effective wear test rig that is capable of simulating RCF, sliding and rolling wear as experienced by the train wheel while moving along railway tracks. For this work, it was decided that twin-disc concept would be used, since literature clearly shown that the method was able to simulate the three damage mechanisms mentioned. The developed twin-disc wear simulator was able to simulate both rolling and sliding wear and parameters including contact load and slip ratio could be changed with ease so to simulate the actual contact conditions between the wheel and rail. Outputs such as coefficient of friction and wheel disc temperature were obtained. The results showed that the severity of wear is heavily dependent on slip ratio i.e., increased with slip ratio, with both coefficient of friction and wear rate increasing with slip ratio.

A Frequency Domain PID Control Strategy for an In-House Friction and Wear Test Rig

The contact behavior greatly influences the damping performance of frictional interfaces. Numerous experimental studies on friction and fretting wear have investigated the evolution of contact parameters. An in-house friction and wear test rig has been developed to obtain hysteresis loops at certain normal forces. However, the test rig lacks load control and is thus unable to ensure precise stabilization at a preset normal force, which affected the hysteresis behavior. In this paper, we developed a frequency-domain PID controller to ensure the stable application of a target normal force with constant (0–300 N) and harmonic (0–50 N) components. Compared to the commonly used time-domain strategy, the control signal error is reduced from 6.30% to 0.54% at 50 Hz. With a 3% error as the standard, the controller enables stabilized control of signals with frequencies up to 300 Hz. Friction experiments on various typical materials are conducted using this improved test rig. The results indicate a general tendency for contact stiffness to increase with a rising normal force, while the relationship between the friction coefficient and the normal force does not exhibit a clear pattern. The contact stiffness is not sensitive to the relative displacement or vibration frequency.

Wear and thermal coupled comparative analysis of additively manufactured and machined polymer gears

This study investigates the potential use of additive manufacturing (AM)-produced gears in the polymer gear industry as an alternative to conventionally manufactured gears. The focus is on comparing the wear and thermal properties of polyamide 6 (PA6) gears, the most commonly used in industry, with those of polyetherimide (PEI) gears manufactured via AM. The research aims to determine whether AM offers any advantages over conventional methods, particularly with regard to wear resistance and thermal performance. The wear behaviour of both types of gears is examined under various operating conditions, with particular attention being paid to the initial wear rates and how they evolve. PEI and PA6 test gears were evaluated using a custom-built gear wear test rig. Throughout the wear test, polymer test gears were subjected to wear by running against a metal gear. The gears were tested at various rotational speeds for up to 1 million cycles. During this process, measurements were taken to determine surface roughness changes, operational noise levels, microstructure analyses using scanning electron microscopy (SEM), and chemical structure analyses using Fourier transform infrared spectroscopy (FTIR). Additionally, thermal properties such as temperature generation and stability are monitored with a thermal camera and infrared thermometer to understand the suitability of each gear material for different applications. PA6 gears demonstrate better wear resistance at low and medium rotational speeds, while PEI gears show superior performance at high speeds. Furthermore, PEI gears display enhanced thermal properties, with lower temperature increases during operation compared to PA6 gears; this can be attributed to the porous structure inherent in AM, which allows for better heat dissipation. The findings suggest that AM-produced PEI gears hold promise as an important alternative in high-speed applications due to their superior wear resistance and thermal performance compared to conventionally manufactured PA6 gears.

Significance of addition of carbon nanotubes and fly ash on the wear and frictional performance of aluminum metal matrix composites

AbstractIn order to improve the wear and frictional behavior of the aluminum metal matrix composites, carbon nanotube, and fly ash were added as reinforcements. Powder metallurgy technique was used to fabricate the hybrid metal matrix composites. Experimentations were carried out using pin on disc type wear test rig. The analyzed experimental results showed that, in comparison to the pure aluminum and mono reinforcement combination, the wear loss and coefficient of friction of hybrid metal matrix composites were greatly reduced. It was noted that compared to pure aluminum wear loss was decreased to 89.58%, 86.97%, 83.3% by adding 0.25, 0.5, 0.75 wt% carbon nanotube (CNT), respectively. By the addition of 4, 8 and 16 wt% FA to pure Al wear loss was decreased to 83.85%, 89.58%, and 78.12%, respectively. It was also noted that compared to Al/8 wt% FA mono reinforced composites, wear loss was decreased to 77%, 71.26%, and 53.22% with the addition of 0.25, 0.5, 0.75 wt% CNT, respectively. With the addition of 4, 8, 16 wt% FA, wear loss decreased to 81%, 88%, and 75% over Al/0.25 wt% CNT composites, respectively. The microstructural study of the worn‐out surfaces revealed low abrasive and adhesive wear by the presence of carbon nanotubes and fly ash in aluminum metal matrix. The reinforcing mechanisms of the wear and frictional properties were also discussed.

Microstructural effects on impact-sliding wear mechanisms in D2 steels: The roles of matrix hardness and carbide characteristics

This study investigates the wear micromechanisms of D2 steels under impact-sliding conditions, offering insights into their performance when used in applications such as trimming dies for high-strength steel sheets where they undergo plastic deformation and chipping. Two D2 steel samples, both with a bulk hardness of 59.7 HRC but different matrix hardnesses and carbide distributions, are tested by using an impact-sliding wear test rig at Hertzian contact pressures exceeding 2 GPa. The sample with a softer matrix exhibits wear primarily through delamination caused by plastic deformation. This initiates cracks at the matrix/primary carbide interface, leading to material loss in the form of large chips. In contrast, the steel with a harder matrix shows reduced wear due to its resistance to plastic deformation. Initially, wear occurs through the fracture of primary carbides. However, with prolonged loading, the matrix begins to soften, adopting a wear mechanism similar to the D2 steel with softer matrix. Notably, smaller primary carbides are associated with improved wear resistance by limiting the initiation sites for cracks, especially at the matrix/primary carbide interface. This understanding enables the selection and design of heat treatments to optimize D2 steel microstructure, thus improving resistance to impact-sliding wear damages observed in processes like trimming.

Comparative evaluation of wear resistance between lithium disilicates and polymer infiltrated ceramics manufactured by computer aided design (CAD) computer aided manufacturing (CAM) against natural tooth enamel

Advances in CAD/CAM technology led to development of monolithic all ceramic restorations with superior esthetics like Lithium disilicate. But the major concern of ceramic materials was its wear towards the opposing enamel. Polymer infiltrated ceramics were developed by incorporating resin polymer in ceramics to produce esthetic stability of ceramics and low abrasive nature of composites and very few studies were done on this material. A total of 30 disc specimens were fabricated by CAD/CAM .15 discs of CAD/CAM lithium disilicate (IPS E.max CAD) and 15 discs of Polymer infiltrated ceramics of dimensions 10mmx3mm. They were named as group 1 (CAD/CAM Lithium disilicate) and group 2(Polymer infiltrated ceramics). 30 tooth specimens were mounted on auto polymerising acrylic resin blocks. Tooth specimens were placed on the upper member of the two body wear testing machine (Pin on disc wear and friction test rig, Magnum) and Lithium disilicate and polymer infiltrated ceramic disc specimens were positioned on disc of wear testing apparatus under constant load of 5kg (49N). The specimens were made to rub against one another in a rotating cycle to simulate oral wear cycle. The test was run for total of 10,000 wear cycles at 30rpm on wear machine for each sample. Wear of group 1 and group 2 and enamel wear of group 1 and group 2 was measured before and after wear test by profile projector.Wilcoxon test was done to compare the groups. Results showed that wear was greater in group 1 (Polymer infiltrated ceramics) compared to group 2 (CAD/CAM Lithium disilicate) and enamel wear of group 1 was greater than enamel wear of group 2. Advances in CAD/CAM technology led to development of aesthetic all ceramic restorations with superior mechanical properties such as CAD/CAM Lithium disilicate. But the major concern of ceramic materials is wear towards the opposing enamel. To meet the above requirements polymer infiltrated ceramics are developed by incorporating resin polymer in ceramics to produce esthetic stability of ceramics and low abrasive nature of composites. The restorative materials should not cause wear to opposing enamel and also should possess wear resistance similar to enamel for its success and longevity. This study was performed to evaluate the wear resistance of CAD/CAM lithium disilicate and Polymer infiltrated ceramics against natural teeth enamel.

Study on the influence of surface roughness on the erosion characteristics of compressor blades

An aluminum alloy erosion wear test rig was built in this study. The wear rates of the target materials at different surface roughness were measured. An improved Finnie model was developed to predict the wear rate for aluminum alloy plates at different surface roughness. The optimized model was used to analyze the effects of different surface roughness on the erosion wear of the main and splitter blades of the compressor. The study shows that as the surface roughness increases from 1 μm to 60 μm, the size of wear concentration areas of the pressure surfaces of the main and splitter blades spread from the blade height of 80% to 30% and 50%, respectively.

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.

Effect of Stroke Length on the Abrasive Wear Characteristics of A-356 (0–10 wt%) SiCp Composite in Reciprocating Sliding Conditions

In this study, abrasive wear behavior of A356/(0–10)wt.% SiCp composites are reported using an in house designed and developed pin-on-reciprocating plate abrasive wear and friction test rig confirming to ASTM G133-05 standards. A356 alloy and A356/10 wt.% SiCp composite are prepared through stir casting method adopting standard foundry practices. The hardness of heat treated A356/10 wt.% SiCp composite is found to be 22.56% higher than A356 alloy. This study primarily focused on the effect of variation of stroke length from 65 mm to 100 mm on the abrasive wear characteristics of A356 alloy and it’s composite at different loads (5, 7.5, 10, and 12.5 N) by keeping a constant sliding velocity of 0.2 m/s slid through 25 m. The abrasive wear is found to be higher for the alloy than the composite. It is also revealed from the experimental investigation that as the stroke length is reduced from 100 mm to 65 mm, the abrasive wear loss of A356 alloy and its composites are found to increase. The reason for increase in wear is attributed to high frequency of oscillation and less energy dissipation per cycle at lower stroke length (65 mm) compared to that at higher stroke length (100 mm). Coefficient of friction (CoF) of tribo pairs tested is found to increase with load at the two different stroke lengths studied.

Investigation on Microstructure, Hardness, Wear behavior and Fracture Surface Analysis of Strontium (Sr) and Calcium (Ca) Content A357 Modified Alloy by Statistical Technique

The aluminum alloy are extensively used in several industrial applications. Stir casting is one of the most frequently accepted methods. In the present investigation, how the microstructure, mechanical and wear mechanics of A357 alloy were impacted by the presence of Sr/Ca was investigated. The outcomes revealed that addition of elements (Sr/Ca) enhance the microstructural features. Uniform dispersal of particulates (Sr/ Ca) in Al357 alloy and also the modified structure of silicon (Si) were observed. Hardness of modified alloy was evaluated by using hardness tester. A result reveals that hardness of modified alloy was improved by increasing in the Sr/Ca content. The wear rate of modified alloy was evaluated by using Pin and Disc wear test rig. Test trials were conducted according to Taguchi technique. L27 array was implemented for evaluation of data. The effect of varying parameters (factors) on wear loss and COF were analyzed using ANOVA (Analysis of Variance) method. ANOVA outcomes shown that, the Sr/Ca content has a better significant impact on wear behavior and COF of the modified alloy. A wear fractography result shows the internal fracture structure of a wornout surface which was studied by SEM analysis.

Influence of the Distribution of Pits on the Friction and Wear Performance of Textured Rolling Bearings under Starved Lubrication

Most of the published documents on the friction and wear properties of textured contact surfaces with partially distributed units (e.g., dots, grooves) are focused on sliding tribo-pairs or journal bearings. To study the friction and wear performance of rolling bearings with different distributions of pits, several patterns were introduced: OS-1/4 (Outside, 1/4 of raceway), OS-1/2 (Outside, 1/2 of raceway), OS-3/4 (Outside, 3/4 of raceway), IS-1/4 (Inside, 1/4 of raceway), IS-1/2 (Inside, 1/2 of raceway), IS-3/4 (Inside, 3/4 of raceway), TS (Two sides, 2/3 of raceway), FT (fully textured) and SR (Smooth reference), with two circumferential interval angles (CFIAs, 1.5° and 2.0°). The dimensions of the pits are the same in all patterns (diameter of 300 μm and depth of 15 μm), which were only prepared on the raceways of the shaft washers of 81107 bearings (nylon cages) using the laser marking method. All bearings were tested under 4000 N, 250 RPM and starved lubrication using a vertical universal wear test rig. Their mass losses and worn raceways were measured and observed. Their surface equivalent stresses were also analyzed and compared. The obtained results show that the influence of different distributions of pits on the tribological properties of rolling bearings is significant. The friction-reducing and anti-wear performance of TS is acceptable, whether the CFIA is 1.5° or 2.0°. A fully textured pattern cannot provide the best tribological properties and its behavior even becomes worse when the CFIA is 2.0°. In this work, when the CFIA is 1.5°, the friction-reducing and anti-wear performance of OS-1/4 is the best among all patterns. Using a smooth reference as a benchmark for comparison, its friction-reducing and anti-wear performance can be enhanced by 60.46% and 16.05%, respectively. The results of this work will be an important reference for the optimal design of the “washers-cage-rollers” contact system for rolling bearings.

Optimization of Coating Parameters on Dry Sliding Wear Behaviour of Ni-Al2O3 Composite Coatings using Taguchi Method

Recent advancements in the field of coating have shown that the Ni-Al2O3 electrodeposited coatings are of excellent wear-resistant, corrosion-resistant. In this study, Ni-Al2O3 composite coating is produced by electrodeposition process by using standard watts bath due to the advantage over other coating techniques. Al2O3 nanoparticles are co-deposited on AA6061 with Nickel. There are many parameters that influence the coating characteristics, however, in this study temperature, current density and percentage of nanoparticle loading are considered as significant parameters. Optimization of the coating parameters is examined by using the Taguchi method. The coating morphology and microstructure are studied using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). The dry sliding wear behaviour of composite coatings is tested on a pin-on-disc wear test rig.

Effects of Single/Compound Pit Texture on the Friction-induced Vibration and Noise of Thrust Cylindrical Roller Bearings

To improve the reliability and service life of thrust cylindrical roller bearings (TCRBs), the effects of single/compound pit texture on tribological properties and on friction-induced vibration and noise were studied. Laser marking equipment was used to create compound pit texture on a shaft washer. A universal friction and wear test rig was used to measure the friction force, vibration acceleration, and noise signals of TCRBs. The differences between the single/composite pit-textured and non-textured surfaces were studied in terms of the friction, wear, and vibration noise properties. The results revealed that the friction force and wear loss of the single/composite pit-textured surface were markedly lower than those of the non-textured surface. Compared to non-textured surface bearings, the friction force and wear loss for textured surface bearings were reduced by 39.6 % and 59.6 %, respectively, when the diameter, depth, and area density of the pit were 300 μm, 10 μm, and 10 %, respectively. The single/composite pit-textured surface exhibited good potential for vibration absorption and noise suppression. It could effectively interfere with the self-excited vibration of the TCRBs friction pair system, thereby reducing the degree of vibration noise of the TCRBs.

Research on the Tribological Behavior of Textured Cylindrical Roller Thrust Bearings with Different Distributions of Pits and Nylon Cages under Dry Condition

Differing from the published documents on the effect of texture distributions of sliding tribo-pairs on their friction and wear properties, this study introduced eight patterns to reveal the influence of different distributions of pits on the tribological behavior of textured rolling element bearings with nylon cages under dry condition, namely: Outside-1/4 (OS1/4), Outside-1/2 (OS1/2), Outside-3/4 (OS3/4), Inside-1/4 (IS1/4), Inside-1/2 (IS1/2), Inside-3/4 (IS3/4), Bothside-1/3 (BS) and full (FP). A fiber laser marking system was used to prepare them on the raceways of the shaft washers of cylindrical roller thrust bearings (81107TN). A vertical universal wear test rig was used to obtain their coefficients of friction under an axial load of 2600 N and a rotating speed of 250 RPM, without any lubricant provided. Their wear losses and worn surfaces were characterized. The influence mechanism of different distributions on the tribological properties was also discussed. The results show that the self-lubricating performance of nylon cages can ensure the continuous operation (≥5 h) of cylindrical roller thrust bearings under dry condition. The influence of outside-distributed patterns on the friction and wear properties of bearings is significant. The friction-reducing effect and wear resistance of full textured group is improved but not the best. The friction-reducing and anti-wear behavior of OS1/2 is similar to that of FP. In this work, OS3/4 can provide the best tribological performance under self-lubricating conditions. Compared with the data of smooth bearings, its average coefficient of friction and wear loss can be reduced by 37.68% and 38.85%, respectively. This work would provide a valuable reference for the raceway design and reliability optimization of rolling element bearings.

Effect of compound pit textures on the friction and wear of thrust cylindrical roller bearings under starved lubrication

PurposeThis study aims to investigate the effect of compound pit textures on the tribological properties of thrust cylindrical roller bearings (TCRBs) using several parameters, such as compound type, pit diameter, pit depth and pit area density.Design/methodology/approachThe surface texture parameters of the shaft washer (WS) raceway include pit diameter (D; 100, 300 and 500 µm), pit depth (H; 10 and 20 µm) and pit area density (S; 10%, 13% and 18%). Pits were produced on the WS of the TCRBs using laser marking equipment. The friction and wear performances of compound pit-textured TCRBs under starved lubrication conditions are studied using a friction and wear test rig. The influence mechanisms of the compound pit texture on the friction and wear properties of TCRBs are discussed through real tests and discussions.FindingsCompared with nontextured bearings, the average coefficient of friction (ACOFs) and wear loss of TCRBs with single/compound pit textures are reduced when rotating under starved lubrication. D has the greatest effect on the COFs curve. When D = 300 µm, H = 10 µm and S = 10%, the ACOF and wear loss are the lowest, that is, 0.0207 and 3.38 mg, respectively. Under the same lubrication conditions, compared with the nontextured bearing group, the COF and wear loss are reduced by 41.4 and 59.6%, respectively.Originality/valueThis study provides a useful reference for the raceways of textured TCRBs.

Investigation of physical, mechanical, thermal, and tribological characterization of tricalcium phosphate and zirconia particulate reinforced dental resin composite materials

The proposed study aimed to fabricate and investigate the effect of nano tri-calcium phosphate and zirconia on the physico-mechanical, thermal, and tribological properties of hybrid dental resin composites. The organic matrix bisphenol a glycidyl methacrylate and triethylene glycol dimethacrylate (50/50 wt%) reinforced with yttria-stabilized zirconia (20 wt%) and tricalcium phosphate fillers (0–4 wt%) produced five dental composite series TZC0, TZC1, TZC2, TZC3, and TZC4. The density and water solubility gradually increased by adding fillers to the dental composite. The maximum water sorption (14.09 ± 3.04 μg/mm3) and water solubility (1.9 ± 0.02 μg/mm3) were indicated by TZC4. The maximum depth of cure was 3.50 ± 0.12 mm for TZC0. The maximum compressive strength exhibited by TZC4 was 41% more than TZC1. The hardness was proportional to the filler loading. The fourier transformed infrared spectra indicated the peak’s nano zirconia and tricalcium phosphate filler shifting at different wave numbers. The specific wear rate was measured on the Pin-on-disc wear test rig. The design of the experiment was performed using Taguchi L25 orthogonal array with four factors: normal load, filler wt%, sliding velocity, and time. The novel hybrid dental resin composite significantly affects mechanical, thermal, and viscoelastic properties.

Mechanical and dry sliding wear analysis of porcelain reinforced SAE660 bronze bearing alloy composite fabricated by stir casting method

In today's competitive global market, the conventional engineering materials need to be replaced with novel materials. The present research aims to investigate the mechanical and tribological performance of the porcelain reinforced conventional bronze bearing alloy (SAE660) composite made by liquid metallurgy stir casting process. The mechanical characterizations of the composites were carried out by means of a Vickers microhardness tester and universal testing machine. A pin-on-disc wear test rig was employed to examine the wear behavior of matrix alloys and composites under atmospheric conditions. After the sliding wear test, the worn surfaces were analyzed with a scanning electron microscope (SEM). The test results revealed that the addition of porcelain as a reinforcement (3, 6 and 9 wt%) significantly enhanced the mechanical and tribological performance of the SAE660 bronze bearing alloy. The composite containing 6 wt% of porcelain exhibited better mechanical properties whereas 9 wt% porcelain reinforced composite exhibited maximum wear resistance. The wear mechanisms such as delamination, ploughing, and abrasion wear were identified as the main wear mechanisms for material removal during the sliding wear test.

Tribological behavior and mechanical properties of transmission wire rope bending over sheaves under different sliding conditions

Wear leads to performance degradation of the wire rope and seriously threatens its service reliability. This paper explored the tribological behavior of a transmission wire rope by a homemade rope-sheave sliding friction and wear test rig. Then, the strength and fatigue performance of the wire rope with different surface wear were investigated using customized test apparatuses. The results show that the friction coefficient (COF) is affected by the rope structure, contact angle and sliding velocity, which decreases from approximately 0.65 to 0.32 with increasing sliding velocity. The friction temperature rise is obviously influenced by the sliding velocity. It increases nonlinearly from approximately 51 °C to approximately 102 °C. The wear characteristics are mainly spalling, furrows and plastic deformation. The wear mechanisms are adhesive wear and abrasive wear. Additionally, with a decrease in sliding velocity, the breaking force decreases from approximately 48.7 kN–41.2 kN, and the bending fatigue life reduces nonlinearly. The maximum bending fatigue times decrease from approximately 9.9 k to 3.2 k. Furthermore, the surface wear accelerates the crack propagation rate of the service wire rope. The fracture mechanism of the wire rope is mainly ductile fracture under tensile loading and brittle fracture under fatigue loading.