Wear Plate Research Articles

ABOUT INFLUENCE OF PARAMETERS OF A WEAR PLATE OF THE NORMAL PROBE ON CHARACTERISTICS FREQUENCY A SPECTRUM AND A PULSE OF A BOTTOM SIGNAL

Computer modelling of an acoustic channel of the normal probe for a reflector as a bottom surface has shown, that increase of amplitude of a pulse echo signal, registered by the probe with a wear plate from epoxy resin with fine – dispersed filler due to increase of its contents, causes reduction of speed of longitudinal waves in a wear plate with the appropriate downturn of the first resonant frequency owing to what the spectrum of a signal may vary essentially. Reception of short pulses, on amplitude of same duration considerably surpassing pulses for protectors from epoxy resin with filler, is provided with application of a protector from mineral ceramics, having own lowest resonant frequency is much higher than the basic own frequency piezo plate. Comparison of experimental and theoretical pulses and spectra of ground signals for direct converters with qualitatively distinguished protectors has confirmed an opportunity of presence of the several expressed maxima of a spectrum of a pulse with oscillating modulation of amplitude for a wear plate from epoxy resin with filler with low speed of distribution of longitudinal waves.

К вопросу об интерпретации эхограмм при контактном способе акустического контакта

The echogram of the ultrasonic pulse flaw detector with the contact testing technique is considered as a convolution when a transducer with a protector matched with the coupling medium receives an acoustic pulse emitted by it through the coupling medium into the load, reflected from it, and from this transducer. A method for calculating echograms for products, transducer, contact gaps (layers) made of any materials, with any value of the contact layer, provided that the acoustic resistances of the materials used are known, is proposed. A method of compensation of interfering reflections for a transducer matched with a coupling medium is proposed. Keywords: u.s. transducer, convolution, reconstruction, interference, sensitivity, resolution, wear plate, contact testing technique.

Preparation and processing properties of magnetically controlled abrasive solidification orientation—solid-phase Fenton reaction lapping-polishing plate for single-crystal 4H-SiC

To improve the ultraprecision processing efficiency and surface quality of single-crystal 4H-SiC substrates, a lapping-polishing plate combining magnetically controlled abrasive solidification orientation and a solid-phase Fenton reaction was prepared. Furthermore, the effects of the concentration ratio of abrasive to Fe3O4 and abrasive types on the physical properties of the lapping-polishing plate and the processing properties for single-crystal 4H-SiC substrates were studied to reveal the lapping-polishing mechanism of magnetically controlled abrasive solidification orientation—solid-phase Fenton reaction. The results show that the concentration ratio of abrasive to Fe3O4 and abrasive types affects the distribution of the magnetic chain string structure and the distribution of abrasive materials, affecting the plate's processing properties. The higher the abrasive concentration is, the higher the material removal rate (MRR), but it affects the abrasive orientation and the solid-phase Fenton reaction. In contrast, the high Fe3O4 concentration strengthens the solid-phase Fenton reaction and weakens the mechanical removal of the abrasive, resulting in low MRR and poor processing quality. When the abrasive and the concentration ratio of abrasive to Fe3O4 are diamond and 1:5, the MRR is the largest (46.5 nm/min), and a smooth surface with a surface roughness Ra of 0.89 nm can be obtained. The magnetically controlled abrasive solidification orientation—solid-phase Fenton reaction lapping-polishing process—is a chemical reaction and mechanical removal process. The chemical reaction can promote MRR and improve the lapping-polishing quality while affecting the lapping-polishing plate's surface microstructure and processing properties. The dynamic equilibrium between the material removal process of SiC substrates and the wear of lapping-polishing plates enable high-efficiency, high-quality and low-damage processing of SiC substrates. This method and plates can be potentially used to achieve the fine lapping and polishing of SiC substrates and other optoelectronic substrates.

A case study on the wear mechanism and stress evolution of graphite plugged bronze wear plate from the field trial

Graphite plugged bronze has been primarily applied as the self-lubricating part in the tough oilless conditions, and understanding the detailed wear characteristics and the contacting stress evolution of graphite plugged bronze was important to improve its design for the in-service reliability. This study investigated the wear characteristics and contacting stress of graphite plugged bronze sliding plate from the field trial by means of the multiple topographic characterizations and computational analysis. The results revealed that abrasive wear and adhesive wear predominated on the contacting surface of graphite plugged bronze plate, accompanied by the localized fatigue and erosion. Computational simulation well illustrated the increasingly accumulated stress at the boundary between bronze and graphite as referenced with the stress evolution of bronze matrix and graphite plug, which was considered to be the leading cause of aggravated wear over time. Finding from this study provided the primary wear features of graphite plugged bronze component, which had potential application for the further optimization of the structural restoration and tribological issues of graphite plugged bronze.

Application of Psidium guajava L. leaf extract as a green corrosion inhibitor in biodiesel: Biofilm formation and encrustation

In this paper guava leaf extract was used as antioxidant additive to biodiesel in order to verify its corrosive properties. The study of the copper exposed to soybean oil biodiesel was carried out at room temperature for 2520 h and at 60 °C for 1440 h. Scanning Electron Microscopy/ Dispersive Energy Spectroscopy (SEM/EDS) and X-ray Diffraction (XRD) results show less wear and oxidation of the copper plates immersed in biodiesel with the additive indicating that it is better protected from corrosive processes presenting an efficiency of inhibition (Ei) of 55.37 % and 21.11 % at room temperature and 60 °C, respectively. At room temperature the effect of using the additive is observed with the naked eye and confirmed by the SEM in which it is verified that the specimen was less attacked compared to neat biodiesel. However at 60 °C the use of the additive showed a significant improvement in the vaporization of biodiesel in the region that was not exposed to the fuel. These behaviors result in less formation of corrosion products on the surface of the copper that was exposed to additive biodiesel according to XRD analysis. The observed positive results are justified due to the physisorption of antioxidant compounds found in the additive on the metallic surface with formation of a protective biofilm on the metal surface.

Characterizing tribological behavior of fresh concrete against formwork surfaces

Concrete walls are constructed by pouring fresh concrete in-between formworks. The lifespan of these formworks is limited due to the abrasive nature of concrete. The present work investigates the wear of metallic and polymeric-coated plates in contact with fresh concrete. Two formulations were studied: standard concrete and self-consolidating concrete. A plane-plane tribometer was used to control the fresh concrete friction against the plates. This device reproduces the implementation of concrete in the formwork. Results revealed a Coulomb friction law within the range of tested normal pressures. The friction testing induced changes in the surface topography of the plates. The evolution in topography were associated to two underlying wear mechanisms: a granulate-formwork solid-solid friction and a capillary-dominated friction.

Seismic Design of Tied Arch Bridge in High Earthquake Region Based on Friction Pendulum Seismic Isolation Bearing

Taking the through-type tied arch bridge with a span of 144m as the research object, the working principle of the friction pendulum bearing is introduced; through the finite element simulation analysis, the seismic performance of the Yunnan Nujiang Dukou Bridge is studied, and the seismic safety evaluation is used to give. The three seismic wave time-acceleration time-history curves are respectively analyzed for the seismic performance of the through-type tied arch bridge when the friction pendulum vibration isolation support and the ordinary steel spherical hinge support are used. The research results show that the use of friction pendulum damping and isolation bearings can delay the vibration response of the superstructure from the seismic excitation, thereby achieving the effect of prolonging the vibration period of the structure and reducing the possibility of resonance of the structure under the action of an earthquake. At the same time, when the friction pendulum support swings back and forth, part of the seismic energy can be consumed by the friction between the wear plates. Compared with ordinary steel spherical hinge bearings, the use of friction pendulum vibration isolation bearings can make the piers of the arch bridge participate in the earthquake resistance together, and the internal force distribution of the piers is also more uniform. However, the horizontal displacement of the pier beams increases significantly, and corresponding protection needs to be taken.

Comparative Characteristics of Wear Resistance of Gas-Dynamic Coatings Obtained Using Electroerosive Carbides

This work presents the results of studying of characteristics of wear resistance of gas-dynamic coatings obtained using electroerosive carbides, prepared by the method of electroerosive dispersing from wastes of VK8 hard alloys in distilled water and illuminating kerosene. Worn plates of the cutting tool from sintered hard alloys of the brand VK8 were used as dispersed material as well as electrodes. Samples with coatings from VK8 powders were prepared on the surface of metal products on a specialized plant for superfast gas-dynamic formation. The results obtained showed that the coatings obtained using electroerosive carbides, prepared by the method of electroerosive dispersion from wastes of hard alloys VK8 in water and illuminating kerosene, possess the best wear resistance due to the significantly higher content of free carbon.

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.

High frequency focused imaging for ultrasonic probe integrity inspection

Most ultrasonic probes present a layered structure that may comprise delay lines, acoustic lens, wear plates, matching layers, electrodes, piezoelectric layers, and a backing block. Probe integrity can be compromised by different defects, such as deficient bonding, presence of air bubbles or porosity, lack of electrical conductivity in electrodes, and deviations in the layers' acoustic thicknesses, impedances or attenuation values. Conventional testing procedures are based on the integral properties of the probe, such as acoustic directivity, sensitivity, and electrical impedance. An alternative technique for the non-destructive inspection of the probe's integrity is presented in this study. The proposed technique is based on imaging of the internal structure using a higher frequency focused ultrasound. Scanning the probe's surface using this focused beam provides two imaging modes: reflection and transmission. In the reflection mode, the higher intensity of the echoes indicates the presence of the defects, such as disbonds, poor acoustic matching or porosity. The main novelty of the proposed technique is in the transmission mode: the probe's electric response to the high frequency focused beam is used to get a 2D distribution of transduction efficiency. Moreover, the probe's response can be gated to separate, both front and back side, responses in the time domain, so the local integrity of an electroacoustic structure is evaluated. To verify the proposed technique, a focused 20 MHz transducer with a focal spot diameter of 0.35 mm was mounted on an ultrasonic scanner and immersed in water above the surface of the probe to be tested. Signals were gated by the layers' thickness, giving the C-scan images corresponding to the different material interfaces inside the tested probes: front face, matching layers, piezoelement and backing. It was demonstrated that the resulting C-scan images are informative in evaluating probe's integrity and layers' acoustic thickness. Comparison of the C-scan images obtained in the reflection and transmission modes shows a good agreement in the structure deficiencies evaluation. The technique proposed is attractive due to its simplicity. It can be useful in several applications: i) the probes already in use can be verified and if any deficiencies are detected, the information obtained can be used to evaluate and guide repair; ii) fabrication quality can be verified by confirming the adhesion of layers and parameters in 2D; and iii) the development of new fabrication routes can be guided, where adherence, compatibility, homogeneity, etc. of new materials or new technologies can be evaluated.

Study on Effect of Aerodynamic Sound Hardening for Wear of Coated Carbide Metal Plates

To increase the durability of metal-cutting carbide plates operating during in harsh technological conditions with impact load, an aerodynamic sound hardening method has been developed that can increase a life of carbide tools up to 3.7 times with a small added cost. The wear of plates hardened by the aerodynamic sound method, after 100 min of cutting, is 1.12–1.7 times less than their un-strengthened analogues. A coating on metal carbide plates does not have a prevailing value when a tool is working with impact loads. While working with impact loads viscosity of an internal plate structure occurs the greatest influence on increasing resistance. For metal-cutting carbide plates during interrupted cutting with significant impact loads, a method of aerodynamic sound hardening is more effective than a coating method, not only in terms of tool performance, but also in the cost of completion itself. Empirical dependences of wear on the rear surface of carbide plates hardened by a aerodynamic sound method and plates with PVD coatings have been obtained in the form of approximation by polynomials of the 5thand 2nddegrees, which are convenient to use in a production environment. It has been revealed the higher carbide plate strength in bending leads to less influence of the method of aerodynamic sound hardening on the increase in wear resistance. So, taking into account the fact that for ВК8-base the ultimate bending strength is 1666 MPa, and for T5K10 it is 1421 MPa, wear reduction after hardening by the aerodynamic sound method for ВП3115-plates with ВК base is 11.5 %, while for ВП3225 – plates with ТК-base – 27.1 %.

A methodology for detection of wear in hydraulic axial piston pumps

An effective asset management has a direct impact on maintenance costs, reliability, and equipment availability, especially in hydraulic machinery. Variable displacement axial piston pump is a major component used in the industry due to its load capacity ratio, pressure management, and high performance. Some of the main faults are wear and abrasion of the valve plates, increasing pressure losses as well as temperature, decreasing volumetric efficiency, and abnormal vibration. The off-line methodology implemented includes preprocessing of the vibration signals taken from the test bench available for this study, the feature extraction using wavelets, a stage of detection and classification through the use of artificial neural networks. Several networks were assessment, such as Adaline, nonlinear, and multilayer perceptron networks. Classification percentages greater than 90% are obtained taking into consideration 5 wear conditions related to the loss of volumetric efficiency.

Methodology for selection of optimum interference fit for enhancing performance of external gear pumps

External gear pumps are the heart of mobile hydraulic equipment in the mining sectors where it requires precise control of work attachment functions, lubrication of transmissions and oil supply to steering control units. The external gear pumps encounter many tribological phenomena such as lubrication and wear of gear teeth, an inner profile of casing, wear plates, and press fitting of journal bearings. The major challenge involved during the design phase is the optimum selection of required interference dimensions between the shaft plain bushings and its housings such as bracket and covers. Though the analytical calculations provide some rough initial sizes, it is a time consuming and tedious process when it comes to different material combinations, non-uniform and unsymmetrical sections of brackets and housings. Also, it is difficult to include the effect of thermal variations and different surface finish conditions of mating surfaces in analytical calculations. Optimum interference dimensions are essential to avoid premature failure of the Pumps due to dislodging of the bushings. In the current study, the required initial interference fit dimensions are computed based on an analytical method for different materials combinations. Further, the effect of the surface finish of mating surfaces and thermal expansion of materials are studied using KISSsoft simulation. The validation of the same has been carried out using an experimental set up with different material and assembly conditions as a comparative study to find the optimum dimensions.

Repair Properties of Desulfurization Pump Part Layers by Direct Energy Deposited Additive Manufacturing Process

Numerous pump systems are applied to industries including power plants; among these, desulfurization transfer pumps are severely eroded by slurry, and require periodic replacement of internal impeller and wear plate parts. When directed energy deposition(DED) in the additive manufacturing process is used to repair parts, it is possible to repair entire parts or sections of them. If there is no discontinuity or inventory of parts, this process is expected to be utilized often in the future.In this study, a deposition test and physical property evaluation were carried out using the DED process to repair wear resistance pump parts for desulfurization transfer. Although it is necessary to develop alloys with excellent deposition conditions and compositions similar to those of the base material, this study conducted experiments on commercially available alloy materials. As a result of evaluating various materials, it was found that a powder composed of an iron-based system had characteristics similar to those of the material to be repaired. Key words: Additive manufacturing, DED(Directed Energy Deposition, Abrasive pump parts, High-chrome white cast iron

Wear plates reinforced with secondary hard alloy

Wear plates reinforced with secondary hard alloy

Research methods for the evaluation of the relevance of application oriented laboratory wear tests

In this work, different research methods and test procedures were examined and compared in order to have a better understanding of the relevance of various application oriented laboratory wear tests relative to the in-service performance of the steels in mining conditions. One of the important results of this study is that quite different wear events can be compared, when the wear rates are presented as the mass loss of the sample divided by the wear area, contact time, and density of the material. However, this kind of information is commonly very difficult to obtain for the in-service samples, and thus normalizing of the results with a reference material is often an easier route. On the other hand, thorough characterization and comparison of the wear surfaces and deformations is essential for the confirmation of the similarity of the wear mechanisms in different cases or different tests. In the studied case of the wear plate of a dumper truck body, several test methods were needed for the experimental simulation of the complex wear environment in the haulage of minerals.

Wear modelling of soil ripper tine in sand and sandy clay by discrete element method

Wear and friction cause huge economic losses in the agriculture and mining industries. Wear simulations of working elements, materials, and surfaces that can reduce downtime and economic losses. This work proposes the use a cone penetration resistance measurement result as option to determine movement resistance of soil ripper tine by the discrete element method. It allows avoiding mechanical properties investigation of soil. Simulation made in sand and sandy clay helps to compare wear track of tine wear plates with actual wear. The actual wear was evaluated by 3D scanning of a soil ripper tine wear plates made from tungsten carbide and cobalt alloy and compared with simulated tines. Wear loss expressed as loss of area at the cross-section of tine wear plate. The maximum wear loss of scanned ripper wear plate at 0–150 mm working depth is 1.8% and simulated-in-sand and simulated-in-sandy-clay 1.2 and 1.7%. The maximum actual wear loss caused 57.9% wear loss of cross-section area at 150–204 mm working depth. Simulation in sand and simulation in sandy clay soil 6.9 and 9% caused by lower soil resistance than in field experiments. Simulations in sandy clay soil increased the draft force by 3.9 and 2.8 times that in the sand, at 0–200 mm depth, for tine parts to account for the stiffness fraction of sandy clay soil. As an alternative, tine wear evaluation is also suggested from shear energy values.

The influence of positioning deposited beads direction to resistance on grind wear plates’ abrasive wear


 
 
 The article presents the results of the study of the significance of influence of positioning deposited beads towards direction of abrasive movement, to resistance on grind wear platesHARDPLATE 100S’ abrasive wear. The study on relevance of influence was conducted by using completely randomized design. The range of study has covered testing the metal-material abrasive wear resistance, macroscopic and microscopic metallographic examination and hardness tests.
 
 

A Novel Approach for Composite Wear Plate Fabrication by Using Vertical Centrifugal Casting

A novel approach of wear plate fabrication by vertical centrifugal casting was proposed and demonstrated in this paper. Wear plates were reinforced by the addition of M7C3 carbide particles during vertical centrifugal casting. The effect of size and the weight ratio of the carbide particles on wear resistance were investigated. The prepared carbide particles were used as 150-2000 μm in size and 3-20 g in weight per casting. Spheroidal graphite cast iron has been used as matrix material. During casting, the machine was operated at 250 rpm. The carbide powders have been formed a local coating of 300-1600 µm thickness on the sample tip surfaces. The average thickness of the composite formed on the sample surface was found to be 1000-1200 µm. The elemental distributions were analyzed by EDS. XRD and XPS were used for characterizing the phase structures. The samples were subjected to a block on ring abrasive wear test. It has been observed that the abrasion resistance of samples having a powder size of 1000-2000 μm has the highest abrasion resistance. DOI: http://dx.doi.org/10.5755/j01.mech.24.6.22473

Wear intensity evaluation in conveying systems – An acoustic emission and vibration measurement approach

Conveying raw materials is essential in heavy industries and mostly accompanied by wear. Impinging of materials cause energy transfer, generating elastic waves. In this work, an acoustic emission (AE) measurement system and an accelerometer for vibrations were utilised to assess different wear phenomena.A 3-fold approach was undertaken: i) identification of characteristic acoustic damage features in a model impact-test; ii) impact tests with raw materials on wear plates in lab-scale; iii) field test of the measurement systems in the harsh environment of a steel plant.Results showed clear frequency changes with decreasing plate thickness. Micro-cracking was indicated by high frequencies, showing the first stage of wear. AE and vibration measurements distinguished raw materials clearly in both, close-to-reality and field testing.