High Abrasive Wear Resistance Research Articles

Tribological study of fourth-stage crusher coatings applied in an iron ore processing plant

In the present work, a tribological study was carried out on concave and mantle linings of cone crushers used in the fourth-stage crushing process of an iron ore processing plant. Initially, an analysis of the characteristics over the lifetime of the applied coatings was carried out, and samples of the parts that suffered the most critical wear were selected to carry out the tribological study. Investigation of the wear mechanism and deformation was performed via microhardness analysis, optical microscopy (OM), and scanning electron microscopy (SEM) measurements. The mantle and concave were composed of the same alloy, austenitic manganese steel with 12% Mn. Abrasion tests in the rubber wheel configuration were performed on the mantle and concave samples, and the results were compared with those of two other commercial alloys of manganese steel (one with 18% Mn and one with 18% Mn and 2.5% Cr). It was observed that concave wear occurs differently from mantle wear. While the concave suffers more indentation, the mantle has a more abrasion-dominant profile. This analysis is of paramount importance for conducting a review of the maintenance strategy. The mantle presented less work hardening and a higher wear rate than the concave. The predominant wear mechanism is abrasion. Austenitic manganese steel with 18% Mn and 2.5% Cr presented high abrasive wear resistance, with a wear rate 18% lower than that of the alloy used in the manufacture of cone crusher linings. Higher hardness values result in a lower wear rate, and the use of austenitic manganese steel with 18% Mn and 2.5% Cr represents an opportunity to increase the useful life of cone crusher linings.

Surface roughness analysis in finishing end milling of Hardox® 450 steel using multilayer graphene-based nanofluid

Hardox® 450 is a structural steel commonly used in the mining and agricultural sectors due to its hardness and toughness combined with high abrasion wear resistance. It is widely known that good surface quality minimizes the occurrence of cracks generating higher fatigue resistance. However, the characteristics of this steel make it difficult to cut, resulting in greater complexity in the choice of process parameters. Additionally, the general industry concern for clean machining encourages the use of lubricooling conditions with less environmental impact. In order to address these difficulties, the paper aims to investigate the performance of multilayer graphene-based nanofluid applied in reduced quantity (NF-RQL) on surface roughness generated by finishing end milling of Hardox® 450 when compared to dry and flood machining. The cutting parameters at three levels were combined, randomized and analyzed via Box–Behnken design. The experimental results showed that the lowest roughness on average values was obtained with NF-RQL (Ra = 0.207 μm), followed by flood machining (Ra = 0.326 μm). The Abbott–Firestone and amplitude probability distribution statistical analysis indicated a greater uniformity of peaks and valleys in the roughness profile obtained by NF-RQL milling than in the other lubricooling environments. All prediction models demonstrated an excellent ability to estimate the roughness values (R-squared > 85%). After the multivariate optimization, NF-RQL and flood conditions generated similar average roughness values (respectively, 0.106 μm and 0.115 μm). However, the material removal rate with NF-RQL (2315 mm3/min) is about 83% higher than flood (1266 mm3/min), justifying its better performance.

Intensification of Restoration of Hydraulic Equipment Components by Iron Plating in the Flow of Electrolyte

The influence of electrolysis conditions and the composition of electrolyte for iron plating in the flow of electrolyte on the adhesion strength, microhardness and wear resistance of coatings were studied. The optimal composition of electrolyte for iron plating and the structure of coatings that provide the highest abrasive wear resistance were determined. Advisability of using iron plating in the flow of electrolyte for restoration of spools for hydraulic control valves was demonstrated.

Properties of Microplasma Coating on AZ91 Magnesium Alloy Prepared from Electrolyte with and without the Borax Addition.

Magnesium alloys, due to their unique properties, low density and high strength properties, are becoming more frequently used in industrial applications. However, a limitation of their use may be the need to ensure high abrasive wear resistance and corrosion resistance. Therefore, magnesium alloys are often protected by applying protective coatings. The paper presents the influence of the modification of the electrolyte composition, with or without the addition of borax, on the morphology (observed by SEM method) and phase composition (analyzed by EDS and XRD) of the formed layers on the AZ91 magnesium alloy, and their abrasive wear (determined with Ball-on-Disc method) and corrosion resistance (evaluated using the immersion method and by electrochemical tests), especially in chloride solutions. It has been clearly demonstrated that the modification of the electrolyte composition significantly impacts the final properties of the protective coatings on the AZ91 alloy formed by the plasma electrolytic oxidation (PEO) process. On the basis of the results, it was found that the new type of PEO coatings with the borax addition, compared to base PEO coatings, showed significantly higher abrasion resistance and an order of magnitude lower corrosion rate.

Electron Beam Surface Hardening

The surface hardening of steel components makes it possible to achieve high abrasive wear resistance without the necessity of hardening the entire cross-section of a given element. As a result, lower stress are introduced and the cost of the process can be reduced. Because of very high heating rates (of up to 10⁹ K/s) as well as the ease of dynamic deflection and focusing, the use of the electron beam to harden component surfaces enables the obtainment of surface layers characterised by required properties. This article constitutes an overview of publications concerning electron beam-based surface hardening.

Influence of Niobium Adding on the Microstructure and Abrasive Wear Resistance of a Heat-Treated High-Chromium Near-Eutectic Cast Iron Alloy

High chromium cast iron (HCCI) with levels around 26% Cr - 2.9% C according to ASTM A 532 IIIA is widely used in systems where high abrasive wear resistance is required. To evaluate the niobium influence, HCCI with 0.5% Nb and 1% Nb additions were melted, besides one without niobium addition of for comparison. For characterization, X-ray diffractometry, scanning electron microscopy (SEM), Vickers microhardness tests, Rockwell C hardness, carbide quantifications, quantification of the retained austenite by Mössbauer spectroscopy, and rubber wheel abrasion test according to procedure A of ASTM G-65 were performed. The results indicated a reduction in the average size, average perimeter, and carbides volumetric fraction (CVF) due to the addition of niobium, also changing the microstructure of the HCCI from eutectic to hypoeutectic. In some regions, NbC0.75 carbides formed a coating around M7C3 carbides. The 0.5% Nb alloy showed the best performance in the rubber wheel abrasive wear test, with a 37% average volume loss reduction as compared to the sample without niobium addition with a 130N load and 34% with a 45N load. The 0.5% Nb alloy also had the highest content of retained austenite among the investigated alloys.

Increasing the Abrasion Resistance of Aluminum Foundry Alloys AL-SI AK9 and AK12 Plasma-electrolytic Treatment

Aluminum casting alloys are used in machine-building, automobile, aviation, electrical and textile enterprises. However, aluminum alloys have low abrasive wear resistance, which significantly hinders their use in technological environments where abrasive particles are present. However, aluminum alloys have low abrasive wear resistance, which significantly hinders their use in technological environments where abrasive particles are present. The method of plasma electrolytic oxidation of plasma electrolyte treatment on aluminum alloys provides high hardness up to 2000 HV, low friction coefficient, high adhesion to the metal base, high environmental friendliness. However, this method does not allow the synthesis of oxide layers with high abrasive wear resistance on cast alloys - silumin. Plasma electrolyte treatment layers synthesized on the most widely used Al-Si foundry alloys have significant disadvantages: low rate of synthesis of the oxoceramic layer - 0.5 - 1 μm / min., Low thickness - up to 140 μm, low microhardness (700-1000 HV) and low abrasion resistance. Plasma electrolyte treatment layers were synthesized on the surface of 30x30 mm plates with a thickness of 4 mm from aluminum casting alloys AK-9 (9% Si) and AK-12 (12% Si) in electrolyte - 3 g / l KOH + 2 g / l Na2SiO3 (aqueous solution of liquid glass) without and with the addition to the electrolyte of 3 g / l of hydrogen peroxide H2O2, pulsed current at a frequency of 50 Hz in the cathode-anode mode at a ratio of currents (Ik / Ia) = 1 and a current density of 20 A / dm2. The thickness of the coatings after synthesis for 120 min was 120 -130 µm .. [4]. Metallographic studies were performed on a scanning electron microscope ZEISS EVO 40XVP with X-ray microanalysis system INCA Energy. The phase composition of the surface layers was investigated using a DRON-3M diffractometer in Cu-K radiation. Conclusions: 1. Plasma-electrolyte treatment of silumins AK-9 and AK-12 increases their microhardness up to 1000… 1300 HV, which causes an increase in their abrasive wear resistance by 14 ... 57 times. 2. Addition to the electrolyte of hydrogen peroxide H2O2 in the amount of 3% of the mass. increases the abrasive wear resistance of silumins after plasma electrolyte treatment by another 30 ... 70%. This is due to the increase in the content of oxide phases αAl2O3, γAl2O3 and the decrease in the content of the silicate phase of sillimanite - Al2O3 • SiO2 in the coating structure.

Hard Chrome Replacement with Cirrus Doped Electroless Nickel Coatings

The intrinsic hardness, high abrasive wear resistance, and corrosion properties of hard chrome coatings have resulted in their wide industrial application. However, chrome plating involves hazards associated with chrome 6+ which affect human health and drive the need to identify viable alternatives. This study investigated the addition of Cirrus alumina Dopant™ to a low phosphorus electroless nickel bath to evaluate the performance of the resulting nanocomposite coating as a potential replacement for hard chrome. A comprehensive comparison for the performance of coatings for alumina doped electroless nickel and a pure low electroless nickel coating were investigated. Results showed that Cirrus doped electroless nickel possessed a minimum hardness of 850HV0.1, high corrosion resistance, excellent abrasive wear resistance, and a Taber Wear Index of 2.25mg/1000 cycles. These attributes suggest Cirrus Dopant™ for electroless nickel may offer an outstanding candidate to replace hard chrome coatings in many applications.

Changes in Abrasive Wear Resistance during Miller Test of High-Manganese Cast Steel with Niobium Carbides Formed in the Alloy Matrix

High-manganese Hadfield cast steel is commonly used for machine components operating under dynamic load conditions. The high fracture toughness and abrasive wear resistance of this steel are the result of an austenitic structure, which—while being ductile—at the same time tends to surface harden under the effect of cold work. Absence of dynamic loads (e.g., in the case of sand abrasion) causes rapid and premature wear of parts. To improve the abrasive wear resistance of high-manganese cast steel for operation under the conditions free from dynamic loads, primary niobium carbides are produced in this cast steel during the melting process to obtain in castings, after melt solidification, the microstructure consisting of an austenitic matrix and primary niobium carbides uniformly distributed in this matrix. The measured hardness of the tested samples as cast and after solution heat treatment is 260–290 HV and is about 30–60 HV higher than the hardness of common Hadfield cast steel, which is 230 HV. Compared to common Hadfield cast steel, the abrasive wear resistance of the tested high-manganese cast steel measured in the Miller test is at least three times higher at the niobium content of 3.5 wt%. Increasing the niobium content to 4.5 wt%. in the tested samples increases this wear resistance even more.

Microstructure and Abrasive Wear Resistance of Metal Matrix Composite Coatings Deposited on Steel Grade AISI 4715 by Powder Plasma Transferred Arc Welding Part 1. Mechanical and Structural Properties of a Cobalt-Based Alloy Surface Layer Reinforced with Particles of Titanium Carbide and Synthetic Metal-Diamond Composite.

The article discusses test results concerning an innovative surface layer obtained using the cladding with powder plasma transferred arc welding (PPTAW) method. The above-named layer, being a metal matrix composite (MCM), is characterised by high abrasive wear resistance, resistance to pressure and impact loads, and the possibility of operation at elevated temperatures. The layer was made using powder in the form of a cobalt alloy-based composite reinforced with monocarbide TiC particles and superhard spherical particles of synthetic metal–diamond composite provided with tungsten coating. The surface layer was deposited on a sheet made of low-alloy structural steel grade AISI 4715. The layer is intended for surfaces of inserts of drilling tools used in the extraction industry. The results showed the lack of the thermal and structural decomposition of the hard layer reinforcing the matrix during the cladding process, its very high resistance to metal-mineral abrasive wear and its resistance to moderate impact loads. The abrasive wear resistance of the deposited layer with particles of TiC and synthetic metal–diamond composite was about than 140 times higher than the abrasive wear resistance of abrasion resistant heat-treated steel having a nominal hardness of 400 HBW. The use of diamond as a metal matrix reinforcement in order to increase the abrasive resistance of the PPTAW overlay layer is a new and innovative area of inquiry. There is no information related to tests concerning metal matrix surface layers reinforced with synthetic metal–diamond composite and obtained using PPTAW method.

High abrasive wear resistance polyethylene blends: an adapted Ratner–Lancaster correlation

Ultra-high molecular weight polyethylene (UHMWPE) is one of the polymers with the best abrasive wear performance that exists, being used in engineering applications where this property is required. Despite its excellent property, UHMWPE still performs poorly in many applications. Therefore, the development of new materials with better properties is always very desirable. In this study, it is presented for the first time that it is possible to obtain polyethylene blends with better wear performance than UHMWPE. Linear polyethylenes, high-density polyethylene (HDPE), high molecular weight polyethylene (HMWPE) and UHMWPE, and blends, HMWPE-UHMWPE (10, 20 and 40 wt%), and HDPE-UHMWPE (20 and 40 wt%), have been studied here. The study was developed based on the correlation between the tensile test and the wear test of these materials. In 1968, Lancaster suggested that the abrasive wear resistance of polymers is strongly related to the product between the stress and strain at breaking obtained from the tensile test. This correlation is known as the Ratner–Lancaster correlation. Although this correlation is suitable for many polymers, it is not suitable for all. HDPE, HMWPE, and UHMWPE are examples of polymers where this correlation is not suitable. With the knowledge that the amorphous phase of polymers is responsible for wear resistance and ultimate tensile properties, a new and more suitable correlation for linear polyethylenes is suggested in this study. This correlation shows that the hardening modulus must be included as a factor to predict the abrasive wear resistance. The blends of HMWPE containing 10 and 20 wt% of UHMWPE showed volumetric loss after the wear test of 47.0 and 45.2 mm3, respectively, while UHMWPE presented a higher volumetric loss, of 55.7 mm3. The excellent performance of the blends was possibly due to a better understanding of the correlation between the tensile and abrasive tests proposed in this study.

High-carbon steel: microstructure and abrasive wear resistance of heat affected zone after welding with fast cooling

The goal of this work is to estimate the abrasive wear resistance of heat affected zone (HAZ) after welding high-carbon low-alloy steel 120Mn3Si2 with fast cooling. The following benchmark data were used: microstructures of HAZ of 120Mn3Si2 steel after welding with cooling in water; abrasive wear resistance of different microstructure constituents of 120Mn3Si2 steel in two-body abrasive wear conditions. It is shown that high abrasive wear resistance of material in HAZ is provided in the vicinity of fusion line. The reason is unstable retained austenite which appears in HAZ as a result of quenching at fast cooling right after welding. The wear resistance of material in HAZ is altered by microstructural changes from austenite to austenite+martensite and finally martensite. The martensitic zone is about 0.5 mm wide and it is followed by zone of tempering of initial structure of steel. Zone of tempering is 1.5-2.0 mm wide and is the only zone of low abrasive wear resistance in HAZ of 120Mn3Si2 steel welded with fast cooling. Welding of 120Mn3Si2 steel with fast cooling in water results in welding joints which have as high wear resistant as the base material or even higher. This enables manufacturing flat welded elements with high wear-resistance and large surface area

Verification of electric steel punching simulation results using microhardness

One of the most dominant manufacturing methods in the production of electromechanical devices from sheet metal is punching. In punching, the material undergoes plastic deformation and finally fracture. Punching of an electrical steel sheet causes plastic deformation on the edges of the part, which affects the magnetic properties of the material, i.e., increases iron losses in the material, which in turn has a negative effect on the performance of the electromagnetic devices in the final product. Therefore, punching-induced iron losses decrease the energy efficiency of the device. FEM simulations of punching have shown significantly increased plastic deformation on the workpiece edges with increasing tool wear. In order to identify the critical tool wear, after which the iron losses have increased beyond acceptable limits, the simulation results must be verified with experimental methods. The acceptable limits are pushed further in the standards by the International Electrotechnical Commission (IEC). The new standard (IEC TS 60034-30-2:2016) has much stricter limits regarding the energy efficiency of electromechanical machines, with an IE5 class efficiency that exceeds the previous IE4 class (IEC 60034-30-1:2014) requirements by 30%. The simulations are done using Scientific Forming Technologies Corporation Deform, a finite element software for material processing simulations. The electrical steel used is M400-50A, and the tool material is Vanadis 23, a powder-based high-speed steel. Vanadis 23 is a high alloyed powder metallurgical high-speed steel with a high abrasive wear resistance and a high compressive strength. It is suitable for cold work processing like punching. In the existing literature, FEM simulations and experimental methods have been incorporated for investigating the edge deformation properties of sheared surfaces, but there is a research gap in verifying the simulation results with the experimental methods. In this paper, FEM simulation of the punching process is verified using an electrical steel sheet from real production environment and measuring the deformation of the edges using microhardness measurements. The simulations show high plastic deformation 50 μm into the workpiece edge, a result that is shown to be in good agreement with the experimental results.

Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings

Multi-element material coating systems have received much attention for improving the mechanical performance in industry. However, they are still focused on ternary systems and seldom beyond quaternary ones. High entropy alloy (HEA) bulk material and thin films are systems that are each comprised of at least five principal metal elements in equally matched proportions, and some of them are found possessing much higher strength than traditional alloys. In this study, CrVTiNbZr high entropy alloy and nitrogen contained CrVTiNbZr(N) nitride coatings were synthesized using high ionization cathodic-arc deposition. A chromium-vanadium alloy target, a titanium-niobium alloy target and a pure zirconium target were used for the deposition. By controlling the nitrogen content and cathode current, the CrNbTiVZr(N) coating with gradient or multilayered composition control possessed different microstructures and mechanical properties. The effect of the nitrogen content on the chemical composition, microstructure and mechanical properties of the CrVTiNbZr(N) coatings was investigated. Compact columnar microstructure was obtained for the synthesized CrVTiNbZr(N) coatings. The CrVTiNbZrN coating (HEAN-N165), which was deposited with nitrogen flow rate of 165 standard cubic centimeters per minute (sccm), exhibited slightly blurred columnar and multilayered structures containing CrVN, TiNbN and ZrN. The design of multilayered CrVTiNbZrN coatings showed good adhesion strength. Improvement of adhesion strength was obtained with composition-gradient interlayers. The CrVTiNbZrN coating with nitrogen content higher than 50 at.% possessed the highest hardness (25.2 GPa) and the resistance to plastic deformation H3/E*2 (0.2 GPa) value, and therefore the lowest wear rate was obtained because of high abrasion wear resistance.

Phase composition and wear resistance of compacts and coatings based on carbides fabricated in W-Fe-C system by wet mechanical alloying

The paper reports on phase composition, microhardness and wear resistance of compacts and coatings based on η-carbides (Fe,W)6C and (Fe,W)12C produced by mechanical alloying of tungsten and iron powders in petroleum ether. The compacts have been prepared by magnetic-pulse compacting, and the coatings being formed on iron substrate by the selective laser sintering. The compacts exhibit microhardness up to 9.6 GPa and high abrasive wear resistance. Friction coefficients are 0.27-0.6 and 0.33-0.53 in frictional pairs with a steel disc and a ball made of WC-Co alloy, respectively, and wear not exceeding 10 µm in the tribo-pairs. The coatings have a microhardness of 16 GPa and friction coefficients of 0.28 and 0.2 for friction with balls made of steel and WC-Co, respectively, with no wear being practically observed in tribo-pairs. Combining the mechanosynthesis and selective laser sintering is shown to be very efficient to fabricate coatings based on η-carbides (Fe,W)6C and (Fe,W)12C possessing high values of hardness and wear resistance.

Effect of High-Temperature Quenching on the Phase Composition, Structure, and Wear Resistance of Ni-Hard Chromium-Nickel Cast Iron

Metallographic, micro-X-ray spectral and X-ray structural analyses have been carried out. The quenching temperature increase from 900 to 1150 °C leads to high abrasive wear resistance in Ni-hard chromium-nickel cast iron. The initial hardness decreased before the test from 60 to 35 HRC due to the fact that the phase composition of the metal base before the wear test changes during quenching from medium-carbon martensite with secondary cementite to retained metastable austenite. It contributes to increase the crack resistance of cast iron. Austenite turns into dispersed friction martensite on the working surface in the process of wear testing or operation, as a result of the impact of abrasive particles. This martensite together with a part of cementite provides a high level of hardening and operability of the cast iron secondary microstructure.

Comparison of Properties of Hardfaced Layers Made by a Metal-Core-Covered Tubular Electrode with a Special Chemical Composition.

In this article, the results of research on the metal-mineral-type abrasive wear of a wear-resistant plate made by a tubular electrode with a metallic core and an innovative chemical composition using the manual metal arc hardfacing process were presented. The properties of the new layer were compared to the results of eleven wear plates manufactured by global suppliers, including flux-cored arc welding gas-shielded (FCAW-GS, Deposition Process Reference Number: 138), flux-cored arc welding self-shielded (FCAW-SS, Deposition Process Reference Number: 114), automated hardfacing, and manual metal arc welding (MMAW, Deposition Process Reference Number: 111) hardfacing T Fe15 and T Fe16 alloys, according to EN 14700:2014. Characterization of the hardfaced layers was achieved by using hardness tests, optical microscopy, confocal microscopy, scanning electron microscopy, and EDS (Energy Dispersive Spectroscopy) and X-ray diffraction analyses. Based on wear resistance tests in laboratory conditions, in accordance with ASTM G65-00: Procedure A, and surface layer hardness tests, in accordance with PN-EN ISO 6508-1, the wear plates most suitable for use in metal-mineral conditions were chosen. The results demonstrated the high metal-mineral abrasive wear resistance of the deposit weld metal produced by the new covered tubular electrode. The tubular electrode demonstrated a high linear correlation between the surface wear resistance and the hardness of the metal matrix of the tested abrasive wear plates. In addition to hardness, size, shape, the dispersion of strengthening phases, and the base metal content, depending on hardfacing technology and technological parameters, impact wear resistance is represented by volumetric loss caused by effect-free or constrained dry abrasive medium contact. The presented results can be used in machine part material selection and wear planning for applications in inspection, conservation, and regeneration interval determination. The obtained results will be applied in a real-time wear rate prediction system based on the measurement of the working parameters.

Wet abrasive wear behavior of WC-based cermet coatings prepared by HVOF spraying

In this study, three kinds of WC-based cermet coatings including WC–CoCr coating, WC–Ni coating and WC–Cr3C2–Ni coating were prepared by the high-velocity oxygen-fuel (HVOF) spraying process. Scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and Vickers hardness tester were used to analyze the microstructure and mechanical properties of these coatings. The WC–CoCr coating presented the highest average microhardness of 1205 HV0.3, and then followed by the WC–Cr3C2–Ni coating (1188 HV0.3) and the WC–Ni coating (1105 HV0.3). The abrasive wear behavior of the WC-based coatings under the conditions of different applied loads and sediment concentrations were studied by a wet sand-rubber wheel tester. The results indicated that the abrasive wear loss rates of all the coatings increased with the increment of applied load or sediment concentration. In addition, the coatings with higher microhardness appeared to have higher abrasive wear resistance. The abrasive wear resistance of the WC-based coatings was 4–90 times higher than that of AISI 304 stainless steel under the same testing condition. The abrasive wear mechanism of the WC-based coatings was deduced to be the extrusion and removal of binder phases, as well as the fragmentation and peel-off of hard phases.

BÖHLER K107

Abstract Böhler K107 is a high-carbon (2.1%), 12% chromium. 0.7 % tungsten, alloy cold-work tool steel that is used in applications where a very high abrasive wear resistance is needed, but where demands on chipping resistance are small. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming and heat treating. Filing Code: TS-799. Producer or source: voestalpine Böhler Edelstahl GmbH&Co KG.

ROLE OF FRICTION ENERGY AND TRIBO-REDUCTION IN ABRASIVE WEAR OF ALUMINA–TITANIA COATINGS

This paper addresses friction energy-induced reduction of TiO2 during abrasive wear and friction of alumina–titania coatings with different TiO2 content. Alumina–13% titania and alumina–40% titania coatings were deposited by atmospheric plasma spray technique. An improvement in fracture toughness and better densification of coatings was observed with an increase in titania content. Alumina–40% titania coating showed lower friction coefficient and higher abrasive wear resistance than alumina–13% titania coating. An increase in friction energy was associated with enhanced reduction of TiO2 to Ti2O3 and an increase in the extent of gamma alumina to alpha alumina phase conversion. These observations along with structural and mechanical properties of coatings could explain differences in tribological response of these coatings. Friction energy parameter (FEP) was used to identify different regimes of wear and degradation mode of coatings.