Wear Track Profiles Research Articles

Tribocorrosion behavior of martensitic stainless cutlery steel in pressed Shanghai Bok Choy

The martensitic stainless cutlery steel is frequently exposed to conditions where there were both wear and corrosion in the daily usage of kitchen cutlery. To understand the degradation mechanism of the cutlery steel under practical application environments, tribocorrosion tests were performed on 60Cr16MoMA martensitic stainless steel (MSS) in 3.5 wt% NaCl solution and pressed Shanghai Bok Choy (pSBC). The results revealed that compared with 3.5 wt% NaCl solution, the 60Cr16MoMA steel exhibited better tribocorrosion resistance in pSBC during sliding. Through analysis of cross-sectional wear track profiles, it was found that the 60Cr16MoMA steel had the least volume loss when tested in pSBC. High performance liquid chromatography-mass spectrometry results showed that flavonoids and ascorbic acid were present in pSBC, which may act as corrosion inhibitors and stabilize the passive film through physisorption or chemisorption. X-ray photoelectron spectrometer results further confirmed that the passive film formed in pSBC was more stable due to higher Fe2+/Fe3+ and Cr2O3/Cr(OH)3 ratios. These findings further confirm the MSS are subjected to the hazards of wear, corrosion and tribocorrosion, and provide important empirical and theoretical support for evaluating cutlery steel volume loss in practical application environments in the future.

Investigating the Wear Behaviors of Silane Coated Silica Filled Glass/Epoxy Nanocomposites

Wear behaviors of silane coated silica (SiO2) nanoparticle-filled glass fiber reinforced polymer composites were investigated depending on the type of silane coating (KH550: -Aminopropyl-triethoxy-silane and KH570: -Methacryloxypropyl-trimethoxy-silane) and nanoparticle percentages within the polymer matrix. Unlike the cases given in most research studies, the silanized silica nanoparticles were used as received. Therefore, the synergistic effects of silanization and nanoparticle reinforcement were successfully applied since the silanization process was eliminated. The matrix modification with the nanoparticles was carried out using an ultrasound homogenizer, and then the modified matrix was reinforced with glass fibers. Scanned electron microscopy revealed the disperse ability of silanized silica nanoparticles within the glass/epoxy composites. The wear behaviors of the developed composites were investigated via a ball-on-disc tribology device. Wear track profiles were obtained depending on the width and depth of the wear. The length of wear track and wear mechanisms were determined by a stereomicroscope. The findings have shown that both types of silane coating and silica nanofiller percentages significantly affected the wear rate of the composite structures.

Microstructure and mechanical properties of FeCoCrNiAl0.1N high entropy alloy nitride coatings synthesized by cathodic arc ion plating using alloy target

To promote the industrial application of high entropy alloy nitride (HEAN) coatings, the cathodic arc ion plating deposition process was explored to deposit FeCoCrNiAl0.1 N using casting HEA alloy targets. We investigated the impacts of nitrogen pressure and bias voltage on the microstructure, mechanical characteristics, and friction behaviors. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to analyze the microstructures. It was found that compositions for all coatings were uniformly and the coatings mainly consisted of FCC-HEA, CrN, AlN, and FeN phases. The nano hardness and plastic deformation resistance, characterized by nano-indentation, both increased with the nitrogen pressure and certain bias voltage (<150 V). Coating deposited with 2.0 Pa and 150 V presented the maximum hardness of 32.9 GPa and the highest H3/E2 value of 0.1 GPa. The hardening mechanism was focused. Coatings deposited with low nitrogen pressure presented better crack resistance under scratch load. The friction behaviors were presented based on the combined studies of friction curves, wear track profiles, and morphologies. FeCoCrNiAl0.1 N coatings revealed excellent wear resistance with relatively lower COF (ranging from 0.43 to 0.51).

Effects of cubic boron nitride (c-BN) nanoparticle addition on the wear properties of carbon FRP composites

Abstract Boron nitride (BN) nanostructures are a relatively new type of filler and highly convenient for aerospace applications due to its high strength, excellent thermal resistance, and acting as radiation shielding. Cubic BN (c-BN) nanoparticle is a structural form in crystalline shape and offers outstanding characteristics because it can provide additional improvements through the thickness of laminated composites. This study investigates the effects of c-BN nanoparticle addition on the wear properties of carbon fiber-reinforced polymer (CFRP) composites. The polymer matrix was modified with c-BN nanoparticles at weight ratios of 1, 2, 3, and 4%, respectively, and then reinforced with carbon fibers. The Vickers microhardness measurements showed that dispersion of c-BN nanoparticles into the matrix dramatically enhanced the surface hardness of the composite structures. Additionally, tribological examination revealed that friction coefficient values of the composites were extraordinarily reduced due to the presence of c-BN nanoparticles. The improved wear resistance was also exhibited with wear track profiles. Scanned electron microscopy images have confirmed the experimental findings. The c-BN nanoparticles can be used as secondary reinforcement for CFRP composites, and these hybrid systems could be strong material candidates for several industries like aviation, aerospace, and electronics due to their excellent wear properties.

The Effects of Reinforcement with TaC on the Microstructure and Wear Properties of Lamellar Graphite Cast Irons

Lamellar graphite cast irons are prevalently used in several industrial applications, especially the automotive industry, due to their high compressive strength, high thermal conductivity, high castability, vibration damping ability, good mechanical strength, friction and wear resistance, better machinability than other cast irons, and good mold filling. In this study, changes in the wear volumes, wear rates, wear track profiles, and friction coefficients of lamellar graphite cast irons in which Tantalum Carbide (TaC) was added at different reinforcement ratios (A (0.025 wt.%), B (0.155 wt.%), C (0.285 wt.%), and K (unreinforced, 0 wt.%)) were investigated. Additionally, by examining the wear surfaces of the samples using a scanning electron microscope (SEM), their wear mechanisms were determined. As a result of the analyses, it was determined that different reinforcement ratios did not have a noticeable effect on wear track profiles under a load of 1 N. On the other hand, different reinforcement ratios showed an effect on wear track profiles under loads of 3 N and 5 N. The most perceptible wear track profile was formed in Sample C under 5 N. It was observed that increased load values resulted in increased wear volumes, but the increases in the wear rates of the samples were not significant, and the numerical values were close to each other. The highest wear volumes were determined in the reinforced C sample and the unreinforced K sample under 5 N load. As the magnitude of the load that was applied increased, the friction coefficients of Samples B and C decreased, but the friction coefficients of Samples K and A increased.

Tribologically induced crystal rotation kinematics revealed by electron backscatter diffraction

Tribological loading of metals induces microstructural changes by dislocation-mediated plastic deformation. During continued sliding, combined shear and lattice rotation result in the formation of crystallographic textures which influence friction and wear at the sliding interface. In order to elucidate the fundamental lattice rotation kinematics involved in this process during the early stages of sliding, we conducted unlubricated, linear single pass sliding experiments on a copper bicrystal using sapphire spheres. Electron backscatter diffraction (EBSD) performed directly on the bulk surface of the wear tracks in the vicinity of the grain boundary reveals crystal lattice rotations by approximately up to 35°. Predominantly, the tribologically induced crystal rotations appear to be kinematically constrained to rotations around the transverse direction (TD) and occur in both grains, irrespective of load (2 to 8 N). We demonstrate that inverting the sliding direction (SD) inverts the sense of crystal rotation, but does not change the principal nature of rotation for the majority of indexed EBSD data. A lower proportion of the crystal lattice rotates much farther around TD (roughly up to 90°), accompanied by a superimposed crystal rotation around ±SD. Analysis reveals that sliding direction and grain orientation exert a systematic influence of how crystal rotations are accommodated. This is rationalized in terms of geometry, anisotropic wear track profiles and slip traces. Under specific conditions, combined crystal rotation and twinning are observed. These detailed insights into the fundamental nature of tribologically induced lattice rotation kinematics provide important guidance for applied research targeting materials with superior tribological properties.

On the wear behavior and damage mechanism of bonded interface: Ceramic vs resin composite inlays

Advances in adhesive technologies have increased indications for the use of inlays. Decrease in the bonded interface integrity due to wear has been cited as the main cause of its failure. However, this process of interface degradation and the influence of inlay material on damage mechanism appear to be poorly understood. Thus, we aimed to compare the wear behavior and interface damage between ceramic and resin composite inlays bonded to enamel under sliding contact and use the experimental findings to support recommendation of the appropriate inlay material. Bonded interface specimens involving tooth enamel and either ceramic or resin composite inlays were prepared and subjected to reciprocating wear tests up to 5×104 cycles. The wear track profiles and morphologies were characterized after increments of cyclic sliding contact using white light interferometry and scanning electron microscopy, respectively. Optical microscopy was used to evaluate sub-surface cracks and their propagation within the samples. A finite element analysis was used to analyze the stress distributions of the bonded interfaces. Composite inlays showed higher wear depth than the ceramic in the early stage (N ≤ 5×102 cycles), while no significant difference was found at the later stage. For ceramic inlay a greater portion of the contact load was concentrated in the ceramic structure, which facilitated cracks and chipping of the ceramic inlay, with rather minimal damage in the adjacent interface and enamel. In contrast, for the resin composite inlay there was larger stress concentrated in the adjacent enamel, which caused the development of cracks and their propagation to the inner enamel. The restoration material could contribute to the stress distribution and extent of damage within enamel-inlay bonded interfaces. A tough ceramic appears to be more effective at protecting the residual dental tissue.

Experimental Investigation on Friction and Wear Behavior of the Vertical Spindle and V-belt of a Cotton Picker.

This study deals with the friction and wear behavior of the vertical spindle and V-belt to improve the reliability, operation and to extend the service life of a cotton picker. The vertical spindle made of low-carbon steel (ST3) was treated by the ultrasonic nanocrystal surface modification (UNSM) technique to control the friction and wear behavior. It was found that the UNSM technique reduced surface roughness and increased surface hardness of the vertical spindle. The friction and wear behavior of the vertical spindle and V-belt was assessed by carrying out tribological tests and the results showed that the UNSM-treated vertical spindle generated a higher friction coefficient compared to the untreated one due to having less slip. In case of wear resistance, unmeasurable wear occurred on the surface of the vertical spindle due to its significant high hardness compared to the hardness of the V-belt that came into contact with the vertical spindle in relative motion. Hence, the wear behavior and mechanisms of the V-belts were systematically investigated and also discussed based on the wear track profiles and micrographs. It can be concluded that the application of the UNSM technique to the vertical spindle may contribute to improve the performance of cotton pickers by reducing the slip and prolonging the service life.

Dry sliding wear research on C45 carbon steel, 41Cr4 alloyed steel and X3CrNi13-4 martensitic stainless steel

In this paper, the experimental research refers to the dry sliding wear behaviour of three type of steels namely carbon steel (C45), alloyed steel (41Cr4) and martensitic stainless steel (X3CrNi13-4). From the X3CrNi13-4 martensitic stainless steel, three different batches with varying percentages of chromium and nickel were analyzed. For all the steels, the research was made using a tribometer (CSM Tribometer) through to the pin-on-disk method (POD), where the friction coefficient and wear rate were determined. All these tests were made according to the ASTM G99 standard, with the same working conditions for all five samples, only for the two batches of the X3CrNi13-4 steel, the motor speed was varied. The obtained results were presented through characteristic graphs for the friction coefficient and through images acquired with a digital and a laser microscope respectively with a specialized software regarding the wear track profiles. It can be concluded that the C45 carbon steel showed the good tribological behaviour with the highest dry sliding wear resistance.

Evaluation of tribological performance of carbon fibre reinforced epoxy composites loaded with graphite platelets under reciprocating linear motion

The objective of this work was to evaluate the effect of graphite platelets used as matrix epoxy polymer reinforcement in the sliding reciprocating wear performance of carbon fibre composites. First, epoxy reinforced composites with different amounts of graphite in weight were produced (0, 7.5, 11.5 and 30 wt %) to ascertain the optimal composition regarding wear resistance. Additionally, carbon fibre reinforced polymer composites were produced, with and without the addition of 7.5 wt% graphite platelets to the polymer matrix, and its wear resistance was also evaluated. The laminated carbon fibre reinforced polymer composites were produced through vacuum assisted hand lay-up method. Reciprocating sphere-on-plate wear tests, using Ø 6 mm spheres of AISI52100 steel as counter-body, were performed during 6 h at room temperature. The tests were carried out using an applied normal load of 4 N, 2 Hz of frequency and 8 mm stroke per cycle. At the end of the tests, the wear losses were estimated through integration of cross-section wear track profiles and the worn surfaces were examined by scanning electron microscopy. The coefficient of friction was accessed during testing. The results showed that the lowest specific wear rate of the polymer composites without carbon fibre was obtained with the insertion of 7.5 wt% of graphite platelets (9.7 × 10−8 mm3/N m) and that increase in the graphite fraction leads to higher material loss as a result of increased fatigue surface. Furthermore, the addition of 7.5 wt% graphite platelets to the epoxy matrix of carbon fibre reinforced polymer composites leads to enhance its wear resistance. The reinforced matrix supports and protects the fibres reducing fibre failure and, consequently, wear.

Comparative Study on Dry Sliding Wear Resistance of Carbon Steel, Alloyed Steel and Cast Iron

The aim of this paper is to study and compare the dry sliding wear resistance of carbon steel, alloyed steel and cast iron, knowing that the sliding wear is a type of deterioration that appears in various practical applications. Experimental research of this study was mainly performed using a tribometer (CSM Tribometer) according to the pin-on-disk method (POD), aiming to determine the coefficient of friction (by graphic representation) and wear rate (by analytical calculation). The tested materials were some iron alloys, namely carbon steels (C25, C45), alloyed steel (34CrNiMo6) and cast iron (EN-GJS-400-15) respectively. The tests were performed complying with ASTM G99 Standard, keeping the same working conditions for all the investigated materials. The results obtained in this study were presented through tables with values, graphs and through characteristic images acquired with a digital microscope and a 3D laser scanning microscope, as well as with the aid of a specialized software (MultiFileAnalyzer) concerning the wear track profiles of the counterbody and tested specimens. The investigations revealed a lower friction coefficient for the cast iron, correlated with a reduced wear rate of the material, which leads to the fact that this type of material has a better resistance to sliding wear resistance compared with the other analysed materials.

Effect of deposition material and heat treatment on wear and rolling contact fatigue of laser cladded rails

To develop a laser cladding technique for repairing rail surface damages due to rolling contact, wear and rolling contact fatigue characteristics of a set of laser cladded rails were investigated using a roller-on-disc test machine. Three deposition materials 410L, SS420 and Stellite 6, were chosen to clad a premium hypereutectoid steel rail under two different heat treatment processes. In the first heat treatment, only preheating at 350 °C was conducted and in the second heat treatment, preheating at 350 °C, post-heating at 350 °C (1 h) then slow-cooling to room temperature was conducted. Preheating the substrate was insufficient to prevent martensite formation resulting from the rapid cooling rate, whereas post heat treatment was beneficial for refining the lamellar spacing and eliminating martensite formation in the clad layer and heat affected zone. Following the roller-on-disc tests, wear loss was calculated from wear track profiles using a laser optical profilometer. The level of surface degradation, surface cracking and spalling was investigated using an optical microscope. Experimental results revealed that SS420 cladding had the highest wear resistant behaviour but severe surface cracks and spalling were found in the worn area. Stellite 6 cladding showed similar wear resistance as the parent substrate rail and the best fatigue resistance behaviour among the three cladded rail samples. Based on this research, Stellite 6 is the most promising deposition material for repairing rails by laser cladding.

On the risks associated with wear quantification using profilometers equipped with skid tracers

Abstract In this study a wear track was generated on aluminium by rubbing it against a hard steel ball. The generated wear track has a typical depth of 50 μm and exhibits marked ridges on its borders. The cross section profiles were measured using two different stylus profilometers equipped either with skidless or skid probes and compared to a skidless reference instrument. It was found that the use of a skid probe can introduce significant distortion of the measured wear track profiles and thus errors in wear quantification. The reason for that is attributed to the presence of the ridges that, by elevating the skid, alter artificially the reference height used for profile measurement.

Characteristic Scales of Wear Track Profiles Generated by Pin-on-Disk Wear Tests

Wear track profiles generated by pin-on disk wear tests under various test conditions were subjected to wavelet analysis and shown to have similar profile characteristics regardless of test conditions and materials. Specifically, the streaks in all wear tracks for both pins and disks showed similar characteristic scales of width and depth, thus making the appearance of individual wear tracks indistinguishable. These results suggest that there must be particular driving mechanisms of generating such characteristic scales of roughness.

2103 線条摩耗痕断面形状の特性について(OS2-1 トライボロジーとその応用(1))

This study investigated the characteristics in the undulation shapes of wear track profiles. Pin-on-disk tests involving boundary lubrication with certain materials and under specific conditions were conducted, with undulation profiles in the resulting wear tracks with many streaks therein being measured. An analysis of wavelets for these profiles showed that all profiles had similar characteristics (i.e., similar major undulation width or height/width ratio, regardless of materials or test conditions).

Shape recovery and stress-induced martensite in TiNi following indentation and wear loading

We present initial findings that are suggestive of the potential for shape-memory and superelastic NiTi alloys to function as useful tribological materials. For example, surface-deformation made with a spherical indenter is found to be almost completely recoverable by the shape-memory effect. A similar form of strain recovery is shown to be possible in thin films and in wear-track profiles. When a martensitic material is subjected to pin-on-disk loading, a substantial fraction of the wear track cross-section can be recovered by heating. It is also shown that the martensite phase can be stress-induced in response to complex loading associated either indentation or pin-on-disk wear tests, indicating that transformational superelasticity may be able to ameliorate wear degradation in the same way that it can limit low-cycle fatigue damage accumulation. Since NiTi can readily be deployed as a sputtered thin film coating, it may be possible to confer these beneficial effects to base metal substrates such as aluminum.

Nanotribological studies of thin CrNx, CrOx and CNx overcoats for magnetic recording applications

This work presents systematic nanotribological studies of thin CrNx, CrOx and CNx overcoats for magnetic recording applications over a wide range of N and O concentrations. Composition and crystal structure were determined by x-ray diffraction and x-ray photoelectron spectroscopy. The nanohardness and modulus of the thin films were measured with a Hysitron nanomechanical testing system. Nanoscratch tests were made using a Nano Indenter II system and used to assess the wear resistance and adhesion of the thin films. AFM was used to evaluate the surface morphology and the details of the wear track profiles. The hardness, modulus, tribological properties (wear resistance, elastic recovery, adhesion, friction coefficient) and surface roughness of CrNx, CrOx and CNx have been compared. The hardness and adhesion of CrNx is comparable to CNx, and the roughness of CrNx is lower than CNx. With a very thin Cr underlayer, CrNx appears to have the potential for magnetic recording applications.

On the running-in behaviour of diamond-like carbon coatings under the ball-on-disk contact geometry

The running-in behaviour of a diamond-like carbon (DLC) coating deposited on M42 tool steel substrate has been investigated on a ball-on-disk wear rig in dry air. During sliding, a classical running-in wear curve with a transition in wear rate from a high initial rate to a low rate with sliding was observed. Variations in friction coefficient with sliding distance were not related with this transition in wear rate. A transfer film was rapidly developed on the uncoated ball surface and wear of the ball was negligible. According to Talysurf measurements and optical observations, the width of the wear track on the disk specimen kept almost invariant with increase in sliding distance after the very initial sliding stages. Major change to the wear track cross-section profiles with sliding was the deepening of the wear track. A simulation model for the variation in wear volume and wear track profiles as a function of sliding distance is presented based on the assumption that there are two different dominant wear regimes with respectively a high wear rate and a low wear rate at contact pressures above and below some critical contact pressure, p c. The model has been assessed using the Hertzian elastic contact analysis and the elastic foundation contact model respectively to analyse contact pressures between the rubbing surfaces. It is shown that the running-in feature of wear results mainly from the presence of this transition in wear rate at different contact pressures. Linear increase in wear volume is expected if the Archard's specific wear rate is assumed to be the same at any contact pressure. Reasonably good agreement between the simulated results and experimental observations has been obtained. The elastic foundation model can be applied to simulating wear processes under any contact conditions.

Characterization of wear damage in coatings by optical profilometry

The accurate determination of the volume loss of plasma- sprayed coatings submitted to abrasive and erosive wear and the visualization of wear track or crater profiles are of major concern when ranking coatings, developing wear- resistant coatings, or identifying the mechanism responsible for failure. The determination of the volume loss by liquid displacement measurements is impractical when the size of coated pieces is large and the volume loss is small. For evaluating coating damage and directly measuring the volume loss, a three- dimensional surface mapping method is proposed. The three- dimensional image of the worn surface is obtained by a laser triangulation method. The experimental setup is basically composed of an illuminating source and a detecting device. The light source is focused on the sample surface, and the reflected light is then collected on a network of charge couple detectors linked to a computer. Because the spot location on the network is a direct function of the measured height, a three- dimensional image can be obtained after scanning the entire damaged surface so that the volume loss can be calculated easily. Intensity- coded depth images of the worn surface and computerized cross sections of the damaged area can also be obtained. Inspection of coatings damaged by abrasion wear or slurry erosion by optical profilometry reveals that the volume loss measurements by this technique are very accurate as opposed to the volume measured by liquid displacement methods or calculated from weight loss measurements. Moreover, intensity- coded depth images of worn surfaces and computerized cross sections of damaged areas provide relevant information about the coating performance or defects resulting from the deposition process.

Effect of Silicon Carbide Whisker and Titanium Carbide Particulate Additions on the Friction and Wear Behavior of Silicon Nitride

A Si3N4/TiC composite was previously demonstrated to exhibit improved wear resistance compared to a monolithic Si3N4 because of the formation of a lubricious oxide film containing Ti and Si at 900°C. Further improvements of the composite have been made in this study through additions of SiC whiskers and improved processing. Four materials—Si3N4, Si3N4/TiC, Si3N4/SiCwh, and Si3N4/TiC/SiCwh— were processed to further optimize the wear resistance of Si3N4 through improvements in strength, hardness, fracture toughness, and the coefficient of friction. Oscillatory pin on flat wear tests showed a decrease in the coefficient of friction from ∼0.7 (Si3N4) to ∼0.4 with the addition of TiC at temperatures reaching 900°C. Wear track profiles illustrated the absence of appreciable wear on the TiC‐containing composites at temperatures above 700°C. Microscopic (SEM) and chemical (AES) characterization of the wear tracks is also included to deduce respective wear and lubricating mechanisms.