Erosive Wear Conditions Research Articles

Study of erosion wear by solid particle of a PMMA/SiO2 hybrid coating with graphene oxide applied on a composite laminate

This study reports the tribological performance of a family of PMMA/SiO2 hybrid coatings with graphene oxide applied on composite laminate substrates. The transformation from graphite to graphene oxide was carried out using a high-energy mill for 90 minutes. The composite laminates of epoxy resin matrix and layers of bidirectional carbon fiber were obtained through the vacuum infusion process. The coatings were applied on the composite laminates using the dip-coating method. To disperse the graphene oxide in the hybrid solutions, an ultrasonic bath (40 kHz) was used during the immersion of the substrate. Tribological tests of erosive wear by solid particle impact (beach sand) were performed on a horizontal erosion test platform under conditions of pressure of 45 psi, impact velocity of 6 m/s, distance between nozzle and specimen of 10 mm and impact angle of 90°. The results showed that coatings with graphene oxide increase their protection against erosion by 50 (9-PMMA/1-SiO2-2GO) to 54% (9-PMMA/1-SiO2-1GO) more than the coating without graphene oxide. The results obtained could be considered for using this type of coating as an alternative protection on the leading edge of wind turbine blades that are exposed to conditions of erosion wear by solid particle impact.

Erosion Wear Analysis on Valve Cage of Cage-Typed Sleeve Control Valve for Coal Liquefaction

Abstract Cage-typed sleeve control valve (CSCV) is the key basic equipment in direct coal liquefaction projects. The working condition of CSCV has the characteristics of high-pressure difference, high velocity, and high solid content. There is a general issue of liquid–solid two-phase erosion wear in CSCV, which can easily lead to the failure of the internal structure in the valve cage. Therefore, it is necessary to study erosion wear characteristics of internal structures in the valve cage. Considering the real conditions of erosion wear in the valve cage, a simplified T-shaped flow path is designed, and the precision of both the liquid–solid two-phase flow model and the erosion prediction model is validated. The flow characteristics and erosion wear characteristics in the T-shaped flow path under different working conditions are studied. Based on the simulation results of different structural parameters and boundary conditions, the erosion wear of the T-shaped flow path is predicted and calculated by the response surface method. Subsequently, the prediction formula for the maximum erosion rate is derived. The formula enables the swift determination of optimal structural parameters for the flow path, aiming to mitigate damage to the valve caused by erosion wear. This work can quickly predict the erosion wear rate of the key areas in the valve cage, which can provide a certain reference value for the life prediction and structural optimization of CSCV, and it can also benefit the safety and maintenance of the coal liquefaction system.

Effect of seawater aging on the erosive wear response of aramid fiber reinforced composites

This study presents the effect caused by the saline environment (artificial seawater) on the physical and tribological properties of laminated composite materials reinforced with aramid fibers when they are subjected to erosive wear by sand particles. Composite materials made by epoxy resin and reinforced with glass fiber, carbon fiber and hybrid fiber (aramid with carbon) were studied. The laminates were superficially reinforced with layers of Kevlar fiber and prepared by the vacuum-assisted resin infusion process. The samples were subjected to a seawater accelerated aging process at 70°C for 1122 h. To reproduce erosive wear conditions of marine structural components, sea sand was used as solid particle under conditions of 4.5 bar of pressure, impact speed of 4.7 m/s and impact angle of 90°. The results showed that aged materials absorb more impact energy with respect to unaged counterparts, causing less material loss and a less depth in the wear track. The information generated by this research work may serve for the design and durability analysis of marine structures such as tidal turbine blades.

ADRC-PID cascade control method for a vehicle mounted and unbalanced barrel pitching system under the conditions of bumpy road and erosion wear

ADRC-PID cascade control method for a vehicle mounted and unbalanced barrel pitching system under the conditions of bumpy road and erosion wear

Erosion Modelling of Structural Materials in the Working Space of Multistage Convective Dryers

The application of different structural materials to manufacture basic parts of drying units of various types was analyzed. It has been established that surface erosion of materials resulting from solid par-ticles' impact is a serious problem for many industrial equipment types using multiphase flow. It is shown that the value of the erosion rate depends on the local particle impact velocity and the impact angle and can be calculated using the software Ansys Fluent 18. The basic principles and criteria for selecting materials for the manufacture of chemical equipment were substantiated. The behavior of steel and polymer material for shelf contact of the convective dryer in the conditions of erosion wear was modeled, the comparative characteristic was made, further research was planned.

Tribological behavior of HVAF-sprayed WC-based coatings with alternative binders

The tribological performance of High Velocity Air-Fuel (HVAF) sprayed WC-based cermet coatings with binders containing no or very limited amount of cobalt was evaluated under dry sliding, erosion, and abrasion wear conditions. The wear and corrosion behaviors of WC-NiMoCrFeCo, WC-FeNiCrMoCu and WC-FeCrAl HVAF sprayed coatings were investigated and compared to standard WC-CoCr coatings as benchmark. Microstructure characterization along with XRD analysis was conducted on all powders as well as the corresponding coatings. Comprehensive post wear analysis was conducted on all coatings subjected to ball-on-disk, gas jet erosion and dry sand-rubber wheel abrasion tests. Moreover, all coatings were exposed to 3.5% (wt./vol.) NaCl aqueous solution to evaluate their corrosion performance through electrochemical testing. XRD results showed negligible phase transformation between the powders and the deposited coatings. The WC-NiMoCrFeCo coating exhibited the best sliding wear and electrochemical corrosion performance, with an average specific wear rate value of 3.1 × 10−8 (mm3·N−1·m−1) and a corrosion current density of 1.9 μA/cm2. This coating also showed comparable abrasive wear resistance to the WC-CoCr coating. Under erosive wear conditions, too, the WC-FeNiCrMoCu and WC-FeCrAl coatings showed a comparable performance to the benchmark. Dominant wear mechanisms for the reference WC-CoCr coating, under sliding wear conditions, were abrasion (deep grooving) and surface fatigue (crack propagation and pitting). On the contrary, no pitting was observed in WC-NiMoCrFeCo and WC-FeCrAl coatings during the sliding wear test. No considerable difference was identified in the wear mechanisms of the different coatings under abrasion and erosion wear conditions. The results highlight the promise of some of the environment friendly binders studied to replace Co.

МИНЕРАЛО-ПЕТРОГРАФИЧЕСКИЙ АНАЛИЗА ГЛИНИСТОГО СЫРЬЯ ТУРКЕСТАНСКОЙ ОБЛАСТИ, ИСПОЛЬЗУЕМОГО В КАЧЕСТВЕ ДОБАВОК К ТЕПЛОИЗОЛЯЦИОННЫМ МАТЕРИАЛАМ

The article discusses the contributes to the development of a new focus on the use of various mixtures of natural raw materials and waste in the construction materials industry as a strategically important direction for solving the environmental burden and recycling industrial waste with a feasibility study that improves the state of the environment. This problem is particularly relevant in the production of building materials used in environmentally distressed areas of the republic and in conditions of intense corrosion and erosion wear. The production of efficient building materials and products that meet the modern requirements of environmental friendliness, basic physical and mechanical characteristics, availability and cost is an important and not fully solved task in the field of construction and the construction materials industry. Analysis have been conducted on the current state of the local availability of perspective materials for high-quality composite construction materials, their chemical and mineralogical and granulometric properties have been studied, the influence of the granulometric composition of the basic properties of a composite material and features of the structure formation during heat treatment were studies; physical and mechanical properties of the obtained compositions were tested. Optimal compositions and technological schemes for the production of composite materials based on the use of technogenic waste, natural raw materials and their mixtures have been developed to ensure the production of high-quality construction products with specified thermomechanical properties.The optimization of compositions and properties of compositions was carried out using mathematical planning methods, which made it possible to predict changes in the properties of composite materials depending on the number, weight of the components and the size of the filler granules. Experimental batches of at least 3 main types of construction products were obtained.

Numerical investigation of flow field and performance of the Francis turbine of Bhilangana-III hydropower plant

Computational fluid dynamics is an alternate tool to predict the performance as well as to investigate the flow field of a hydraulic turbine at different operating conditions. The objective of this paper is to analyze the flow field numerically and to predict the performance of Francis turbine of Bhilangana–III power plant. A numerical model of the prototype Francis turbine is undertaken to perform the simulation under the actual working condition of hydropower. The steady-state simulation has been performed at different operating conditions such as high load, part load, and best efficiency point using two turbulence model k-ω shear stress transport (SST) and standard k-ε with zero clearance gap and with a gap due to erosion. Based on computational results, an attempt has been made to compare the performance of the turbine under erosive wear conditions. The computational results are very close to the expected performance characteristics of the prototype turbine under no-gap condition. A difference of 0.24% and 1.71% in efficiency is observed between the numerical and prototype hill chart curve at the best efficiency point (BEP) and full load conditions, respectively. The simulation has also been performed with a clearance gap of 1.85 mm to study the effect of the gap, due to erosion, on the efficiency. The leakage flow-through 1.85 mm clearance gap has resulted in a decrease in the efficiency of the turbine. The efficiency drops around 5.73 % at BEP condition and 5.83% at full load condition. These computational results may be useful for further study of the turbine of Bhilangana–III power plant.

Concept of an Experimental Setup for Testing the Technology for the Formation of New Anti-Corrosion Coating Materials Using Low-Temperature Supersonic Heterogeneous Flows

The article describes the creation of the concept of an experimental setup for testing the technology for the formation of new anti-corrosion coating materials using low-temperature supersonic heterogeneous flows, which allows scientific research to be carried out in a wide range of tasks of practical interest in order to create protective coatings for metal products operating under conditions of erosion and corrosion wear.

Erosive wear analysis of propeller blade coated with tungsten carbide cobalt by high-velocity oxy-fuel spray method

In the present study, the erosive wear of boat propeller blades with tungsten carbide cobalt (WC-Co) coatings by high-velocity oxy-fuel (HVOF) under different erosive wear conditions were investigated and compared with the wear of uncoated one. The (WC-Co) coating was deposited on Al7034 T6 composite reinforced with (Al2O3) and (SiC) particle in different weight percentages. Micro hardness test was employed to determine the hardness of the composite substrate. Eroded surface of the substrate was examined through scanning electron microscope (SEM). Finite element modelling was used to analyse the fracture surface of the propeller blade. Impact analysis was used to determine the stresses induced and deformation evolution under various impact condition. It is shown that crack was initiated from the surface of the blade and finally damages the blade at velocity 500 m/s under cyclic loading. This damage causes the improper functioning of the propeller blade and induced aerodynamic forces to increase the vibrational amplitude of the rotor blade. Results show that (WC-Co) coated propeller blade predominant over the life of the uncoated blade.

Erosive wear analysis of propeller blade coated with tungsten carbide cobalt by high-velocity oxy-fuel spray method

In the present study, the erosive wear of boat propeller blades with tungsten carbide cobalt (WC-Co) coatings by high-velocity oxy-fuel (HVOF) under different erosive wear conditions were investigated and compared with the wear of uncoated one. The (WC-Co) coating was deposited on Al7034 T6 composite reinforced with (Al2O3) and (SiC) particle in different weight percentages. Micro hardness test was employed to determine the hardness of the composite substrate. Eroded surface of the substrate was examined through scanning electron microscope (SEM). Finite element modelling was used to analyse the fracture surface of the propeller blade. Impact analysis was used to determine the stresses induced and deformation evolution under various impact condition. It is shown that crack was initiated from the surface of the blade and finally damages the blade at velocity 500 m/s under cyclic loading. This damage causes the improper functioning of the propeller blade and induced aerodynamic forces to increase the vibrational amplitude of the rotor blade. Results show that (WC-Co) coated propeller blade predominant over the life of the uncoated blade.

Evaluation of Spheroidization on Erosive Wear of ASTM A106 Steel Used in Heat Exchangers

One of the problems encountered in heat exchangers working at high temperatures is the degradation caused by erosive processes, especially in coal-fired power plants. One of the factors that contribute to the degradation of the material is the microstructural changes, like the spheroidization of the carbides. This reduces the mechanical strength of the material and consequently accelerates its wear process. The objective of this work was to evaluate the effect of spheroidization under erosive wear conditions on ASTM A106 steel. The samples were submitted to different treatment times and temperatures, aiming to generate spheroidization in the samples, later submitted to erosive wear tests. Loss of mass, microstructures and mechanical strength were evaluated from the microhardness, with the evolution of the spheroidization process. The samples with higher level of spheroidization, obtained in the temperatures of 730 ° C in times above 50 hours presented greater reduction of hardness that resulted in greater losses of mass. In general, with the increase of spheroidization, there is reduction of mechanical resistance and erosive erosion, but with a gradual reduction in wear rate. This is possibly due to the increased ductility / toughness of the matrix, which delays the process of debris formation on the ASTM A106 steel surface during the hot erosive process.

Reprint of ‘‘Computational study of the particle size effect on a jet erosion wear device’’

Computational fluid dynamics (CFD) is a useful tool to predict the erosion behaviour over geometries exposed to conditions of severe erosion wear. This work shows how CFD can be used to virtually characterize the wear behaviour of materials used in several hydraulic components, including turbomachinery systems, in which it is important to consider the effect of particle size. In addition, this work develops a methodology for determination and validation of the constants involved in the well-known Tabakoff-Grant model for erosion prediction using the erosion wear obtained via erosion testing in a jet tribometer reported in the literature as a reference. From the experimental data, an optimization algorithm was performed to determine the optimal values of Tabakoff-Grant model constants for ASTM A743 grade CA6NM martensitic stainless steel. The simulated erosion rate agrees with the experimental data for the material analysed in jet erosion simulations with impact angles ranging from 15° to 90°. The change of the angle of maximum erosion rate for small particles, which has been reported in the literature via experimentation, was explained satisfactorily. The results showed that the erosion rate with smaller particles is affected by fluid flow, since small particles tend to follow the flow streamlines, while larger particles move according to the conditions imposed by the jet at its outlet. The effective impingement angle against the surface for small particles is lower than the impingement angle for large particles; therefore, the angle of maximum erosion rate, measured between the jet and the sample's surface, for small particles increases.

Computational study of the particle size effect on a jet erosion wear device

Computational fluid dynamics (CFD) is a useful tool to predict the erosion behaviour over geometries exposed to conditions of severe erosion wear. This work shows how CFD can be used to virtually characterize the wear behaviour of materials used in several hydraulic components, including turbomachinery systems, in which it is important to consider the effect of particle size. In addition, this work develops a methodology for determination and validation of the constants involved in the well-known Tabakoff-Grant model for erosion prediction using the erosion wear obtained via erosion testing in a jet tribometer reported in the literature as a reference. From the experimental data, an optimization algorithm was performed to determine the optimal values of Tabakoff-Grant model constants for ASTM A743 grade CA6NM martensitic stainless steel. The simulated erosion rate agrees with the experimental data for the material analysed in jet erosion simulations with impact angles ranging from 15° to 90°. The change of the angle of maximum erosion rate for small particles, which has been reported in the literature via experimentation, was explained satisfactorily. The results showed that the erosion rate with smaller particles is affected by fluid flow, since small particles tend to follow the flow streamlines, while larger particles move according to the conditions imposed by the jet at its outlet. The effective impingement angle against the surface for small particles is lower than the impingement angle for large particles; therefore, the angle of maximum erosion rate, measured between the jet and the sample's surface, for small particles increases.

Analysis of economic impact from erosive wear by hard particles in a run-of-the-river hydroelectric plant

Small-scale hydroelectric plants, primarily run-of-the-river designs, are regularly subjected to hard particle wear and cavitation erosion due to the wide range of operating points. Depending on the severity of the operating conditions and erosion damage experienced by the machine throughout its service life, the operating companies of these facilities will be impacted. The impact will be technical, operational, logistical, and economic. A small-scale generation plant located in Amaime River in Colombia, is one such case, where severe wear occurs in the turbine components, with a consequent reduction of efficiency. In this study, the analysis of the erosion damage has been expanded and supplemented by computational fluid dynamics (CFD). From this approach, correlations between the wear rate and power output were obtained. Likewise and in conjunction with the computer estimates, a methodology to analyse the costs associated with wear based on historical data of operation was developed, creating a strategy of operation based on a stopping criterion that depends primarily on sediment concentration, turbinated flow, and wear level. The methodology optimizes the use of generators, which takes into consideration the revenue generation and the costs associated with operation and maintenance of pieces under conditions of intrinsic erosion wear in the facility.

High-temperature erosion of Fe-based coatings reinforced with cermet particles

High-velocity oxy-fuel sprayed, iron alloy-based powder coatings, reinforced with tungsten carbide–cobalt (WC–Co) and titanium carbide–nickel molybdenum (TiC–NiMo) cermet particles, are compared under high-temperature abrasive–erosive wear conditions. Both WC–Co and TiC–NiMo particles underwent fracture, as well as dissolution, during the spraying process, but in the case of WC–Co particles this process was remarkably less intensive. Under the low impact angle conditions, the WC–Co particle-reinforced coating exhibited 1.1 times lower wear than the TiC–NiMo particle-reinforced coating because of the larger amount of the reinforcement remaining. Under the normal impact angle conditions, the WC–Co particle-reinforced coating showed 1.2 times lower wear than the TiC–NiMo particle-reinforced coating because of the resulting larger size of the WC–Co reinforcement and a more ductile matrix.

Mechanical characterizations and development of erosive wear model for Al2O3-filled short glass fiber-reinforced polymer composites

In the present work, short glass fiber-reinforced polyester-based hybrid composites are fabricated by the incorporation of Al2O3 particulates with three different weight percentages (0 wt.%, 10 wt.% and 20 wt.%) to evaluate their physical, mechanical, and thermo-mechanical behavior. A theoretical model has been developed for erosive wear conditions and results are compared with the experimental outcomes in order to validate the model. The mechanical properties are simulated using an explicit FE code software ANSYS. In this work, erosion test is conducted by using popular evolutionary Taguchi’s (L27) orthogonal array design to optimize the experimental results. It is observed from the analysis that the peak erosion rate occurs at 75° impingement angle for Al2O3-filled composites, whereas for unfilled composites, it occurs at 60° impingement angle. The thermo-mechanical characteristics such as storage modulus (E′), loss modulus (E″), and damping properties (Tan δ) are investigated in the temperature range of 25–200 ℃. It is observed that the slope corresponding to the temperature-dependent decay of the storage modulus for 10 wt.% and 20 wt.%, Al2O3-filled composite is much higher as compared to 0 wt.% Al2O3-filled composite in the temperature range of 25–75 ℃. However, the storage modulus for 10 wt.% and 20 wt.% Al2O3-filled composites remain almost same in the range of 25–60 ℃. Finally, the surface morphology of the eroded composites is examined by using scanning electron microscope and the possible wear mechanisms are discussed.

Erosive Wear Characteristics of Plasma-Sprayed Coatings of Glass Microspheres Premixed With TiO2 Particles

In this article, plasma-sprayed coatings of borosilicate glass microspheres (BGM) premixed with TiO2 particles in different proportions are deposited at various input power levels of the plasma torch. Erosion wear characteristics of these coatings are investigated following a plan of experiments based on the Taguchi technique, which is used to acquire the erosion test data in a controlled way. The study reveals that the impact velocity is the most significant among various factors influencing the wear rate of these coatings. An artificial neural network (ANN) approach is then implemented taking into account training and testing procedures to predict the triboperformance under different erosive wear conditions. This technique helps in saving time and resources for a large number of experimental trials and successfully predicts the wear rate of the coatings both within and beyond the experimental domain. This article proposes an integrated application of ANN and Taguchi's experimental design for analyzing and predicting the solid particle erosion wear response of a new class of coatings.

Nanostructured hard coatings: the key to safe operation of equipment in extreme conditions

Two main classes of hard coatings based on tungsten and tungsten carbides prepared by chemical gas-phase sedimentation are considered in this work. The coatings possess high hardness (11–40 GPa) and thickness (12–100 µm). Results on abrasive and corrosion resistance in solutions of hydrogen sulfide, inorganic acids, and other aggressive environment are presented. All these coatings are promising for use in extremely severe conditions of abrasive, corrosion, and erosive wear owing to a unique combination of chemical stability, hardness, viscosity, and crackand impact-resistance.

Triboperformance Analysis of Coatings of LD Slag Premixed with TiO2 Using Experimental Design and ANN

This article reports on the analysis of triboperformance in regard to the erosion wear of a new class of coatings by an integrated implementation of Taguchi's experimental design and artificial neural networks (ANNs). Plasma-sprayed coatings of LD slag premixed with TiO2 in different weight proportions are deposited on metal substrates at various input power levels of the plasma torch. Solid particle erosion trials, as per ASTM G 76 test standards, are conducted on the coating samples following a well-planned experimental schedule based on Taguchi's design of experiments. An air jet–type erosion test rig capable of creating reproducible erosive wear situations is used. Significant process parameters predominantly influencing the rate of erosion are identified. The study reveals that the impact velocity is the most significant among various factors influencing the wear rate of these coatings. A prediction model based on an ANN is proposed to predict the erosion performance of these coatings under a wide range of erosive wear conditions. This model is based on the database obtained from the experiments and involves training, testing, and prediction protocols. This work shows that an ANN model helps to save time and resources that are required for a large number of experimental trials and successfully predicts the erosion wear rate of the coatings both within and beyond the experimental domain.