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This study is focused on improving the mechanical properties and slurry erosion resistance of traditional Ni–20Al₂O₃ and Ni–20Cr₂O₃ thermal spray coatings by reducing the 5% of Al₂O₃ and Cr₂O₃, respectively, and addition of 5% TiO₂ feedstock in both coatings. Thermal sprayed powders were thermally sprayed on SS-420 substrates with high-velocity oxy-fuel (HVOF) method. A lab-scale pot tester was used to conduct the wear testing at low rotating speeds of 750, 1000, 1250, and 1500 rpm. To create severe accelerated conditions, a high mass flux (35–50 wt.%) of fly ash particles was used. Multi-sized fly ash slurries ranging from $<53$$\mu$m to 250$\mu$m were used during the experiments to evaluate the impact of particle size fraction on the erosion over a 30–120 min time-period. Coatings’ surface characterization was done to examine more about their composition. According to the findings, the addition of 5% TiO₂ powder to both Ni–15%Al₂O₃ and Ni–15%Cr₂O₃ coatings significantly improved their wear resistance of SS-420. This occurred because of the enhancement of hardness as well as brittleness by 5% TiO₂ in matrix of Ni–15%Cr₂O₃ and Ni–15%Al₂O₃ coatings. Moreover, TiO₂ particles aid in strengthening of Cr₂O₃ and Al₂O₃ reinforcements and the binding with matrix. Also, the results showed that Ni–15Cr₂O₃–5TiO₂ coating showed superior wear resistance compared to Ni–15Al₂O₃–5TiO₂ coating.

An atmospheric plasma spray deposition process was adopted for coating regular-shaped, Stellite 6 powder directly on a rolled 3mm size AISI 304 austenitic grade stainless steel substrate without any intermediate bond layers. Coating thickness as measured in a scanning electron microscope was obtained as 74 $\mu$m, 128 $\mu$m, and 215 $\mu$m. An experimental investigation of the functional behavior such as corrosion, microhardness, and erosion of the coated steel at different operating temperatures was undertaken to determine the suitability of its application in the industry. Erosion tests were conducted in an air jet tribo-tester utilizing alumina as an erodent with normal impingement angle at room temperature, 300^∘C, and 600^∘C. It was difficult to identify a single coating thickness that can be satisfactorily used for superior erosive wear properties with corrosion resistance. So modern management tools such as tri-vector and technology sieve analysis procedures as identification techniques were adopted for the selection of the best coating thickness by complying with the mechanical, erosion, and corrosion resistance properties. Steel coated with 128-$\mu$m coating thickness provides the best result for a combination of functional characteristics.

A nickel superalloy such as IN625 is widely employed in the oil, chemical processing, nuclear, and aviation industries due to its exceptional high-temperature strength, hardness, and corrosion resistance characteristics. These industries often require components with intricate and complex geometries that must adhere to close tolerances with adequate surface finish. Fiber laser beam machining (FLBM) has emerged as a significant advancement in fabrication technology, creating intricate forms and structures, especially in superalloys. This work aims to analyze the effect of laser frequency ($L_F)$, number of passes ($N_P$), laser power ($L_P)$, and scanning speed ($S_S$) in the machining of IN625 to achieve minimum surface undulation ($S_U$) and maximum erosion quantity ($E_Q$). The responsive surface methodology (RSM) was employed to model and optimize the parameters. The optimal condition was identified as $L_P$= 10.5W, $N_P$= 18, $S_S$= 283mm/min, and $L_F$= 18kHz; confirmation trials showed an improvement of 8.0% in $S_U$ and 19.75% in $E_Q.$ The influence of scanning speed on surface undulation and erosion quantity is significant. Analysis of variance (ANOVA) indicates that scanning speed contributes the most to surface undulation (70.48%) and erosion quantity (72.90%), followed by the number of passes with contributions of 13.94% to surface undulation and 14.41% to erosion quantity. Additionally, the surface topography and morphology of the machined surface are analyzed using 3D topography images and scanning electron microscopy (SEM) images.

This study involves the preparation of hybrid bio-composites using the hand lay-up method, with epoxy resin serving as the matrix and natural fibers as the reinforcement. The primary objective was to conduct a mechanical and tribological analysis of jute–coir and banana–coir hybrid composites, as well as neat coir bio-composites. The results indicated that the jute–coir hybrid composite exhibited the lowest water absorption (7.6%) and thickness swelling (6.8%) when compared to the banana–coir and neat coir bio-composites. Moreover, the jute–coir composites demonstrated superior hardness and strength, with a higher hardness (78HRB) and tensile strength (120MPa) compared to other bio-composites. Furthermore, sliding and erosion wear tests demonstrated that the jute–coir bio-composite displayed excellent resistance to abrasion and erosion under various wear conditions. As a result, the jute–coir composite, with its reduced thickness swelling and water absorption and favorable mechanical and tribological properties, holds potential for application in diverse areas such as railway coach interiors, aircraft industries for interior components, as well as everyday items like plates and spoons.

Multiphase flows occurring in circular curved pipes exhibit important physical phenomena.They are characterized by a large pressure drop and are composed of different phases. In the past, erosion–corrosion was measured through the use of experimental methods. Today numerical simulation models provide a more in depth look into the problem of erosion. Solid particle erosion is of major concern in the industrial engineering sector. In this study, erosion occurring in a (90)-degree elbow has been simulated. The generated two-dimensional data was done through the use of the Commercial software ANSYS Fluent. The primary idea comes from the petrochemicals industry. To overcome this problem, counter measures are proposed in this paper to the piping setup in order to protect pumps from unwanted excessive sand concentrations. Note that the physical properties of the simulated fluid mixture are taken the same as for the real-studied sample.

Employing an effective cellular automata model, we investigate and analyze the build-up and erosion of soil. Depending on the strategy employed for handling agricultural production, in many cases we find a critical dependence on the prescribed production target, with a sharp transition between stable production and complete breakdown of the system.

Strategies which are particularly well-suited for mimicking real-world management approaches can produce almost cyclic behavior, which can also either lead to sustainable production or to breakdown.

While designed to describe the dynamics of soil evolution, this model is quite general and may also be useful as a model for other renewable resources and may even be employed in other disciplines like psychology.

Gas bubbles are the most potent naturally-occurring entities that influence the acoustic environment in liquids. Upon entrainment under breaking waves, waterfalls, or rainfall over water, each bubble undergoes small amplitude decaying pulsations with a natural frequency that varies approximately inversely with the bubble radius, giving rise to the "plink" of a dripping tap or the roar of a cataract. When they occur in their millions per cubic metre in the top few metres of the ocean, bubbles can dominate the underwater sound field. Similarly, when driven by an incident sound field, bubbles exhibit a strong pulsation resonance. Acoustic scatter by bubbles can confound sonar in the shallow waters which typify many modern maritime military operations. If they are driven by sound fields of sufficient amplitude, the bubble pulsations can become highly nonlinear. These nonlinearities might be exploited to enhance sonar, or to monitor the bubble population. Such oceanic monitoring is important, for example, because of the significant contribution made by bubbles to the greenhouse gas budget. In industry, bubble monitoring is required for sparging, electrochemical processes, the production of paints, pharamaceuticals and foodstuffs. At yet higher amplitudes of pulsation, gas compression within the collapsing bubble can generate temperatures of several thousand Kelvin whilst, in the liquid, shock waves and shear can produce erosion and bioeffects. Not only can these effects be exploited in industrial cleaning and manufacturing, and research into novel chemical processes, but we need to understand (and if possible control) their occurrence when biomedical ultrasound is passed through the body. This is because the potential of such bubble-related physical and chemical processes to damage tissue will be desireable in some circumstances (e.g. ultrasonic kidney stone therapy), and undesireable in others (e.g. foetal scanning). This paper describes this range of behaviour. Further information on these topics, including sound and video files, can be found at .

The resistance, mass transfer, erosion and arc properties of a new contact material named Ag/LaFe_1-xNi_xO₃ conductive ceramics were investigated. Ag/LaFe_1-xNi_xO₃ performed well under low voltage conditions in contrast with other contact materials such as Ag/CdO and Ag/SnO₂. After 5000 make-and-break operations, life test was made and the surface analysis method together with an arc voltage waveform was used to research the corrosion resisting and mass transfer properties. It was found that the conductive ceramics used in the contact materials could influence the resistance performance and, in turn, influence the mass transfer, erosion and arc characteristics.

The use of silicon-based ceramics and composites as combustor liners and turbine vanes provides the potential of improving next-generation turbine engine performance, through lower emissions and higher cycle efficiency, relative to today's use of super alloy hot-section components. As a series of research for FOD resistant, a particle erosion wear test was carried out for continuous Pre-SiC fiber-reinforced SiC matrix composites with a new concept of lab. scale fabrication by LPS process. The result shows that aperture (some form of porosity) between fiber and interface has a deleterious effect on erosion resistance. Aperture along the fiber interfaces consequently causes a severe wear in the form of fiber detachment. Wear rate increase proportional as contents of open porosity increases. For nearly full dense composite materials of about 0.5 % porosity, are about 200 % more wear-resistant than about 5 % porous composites. Grain growth and consolidate condition of matrix which directly affects to FOD resistant are also discussed.

In order to study the influence of solid particles in lead–bismuth alloy on the safety of nuclear main pump, DPM (Discrete Phase Model) is used to calculate the wear rate of the impeller of nuclear main pump under different operating conditions. By comparing the erosion rate and the most severe erosion area under different working conditions, the most unfavorable operating conditions are obtained. The results show that the erosion of impeller caused by solid particles is the most serious when the inlet velocity of particles u is 0.4m/s and particle size D is 100$\mu$m. Under the small particle size, the impeller erosion concentrated on the suction side of the blade, and under the large particle diameter, the erosion concentrated on the pressure side, and the erosion is more serious. With the increase of solid particle velocity, the erosion of the impeller increases first and then decreases. The erosion severity of impeller and front and rear cover plates caused by solid particles is not consistent. The above research can provide guidance for the anti-wear design and safe operation of the nuclear main pump impeller.

In this paper, new operational definitions of binary morphological, both conditional and nonconditional, operations are proposed. The new operations are applied to detect boundary points from binary images. Comparisons of boundary detection algorithms using proposed, standard morphological, and gradient-based operations, showing the effectiveness of the proposed operations, are given. Comparative hardware implementations of standard and proposed morphological operations are also given. Main distinguishing aspects of the new operations are: speed and low hardware implementation (i.e., e.g., low number of buffers and D-Flip–Flops).

This paper shows how mathematical morphological operators can be applied to computer go. On the one hand, mathematical morphology is a very powerful tool within image processing community. On the other hand, the Zobrist's model is well known within the computer go community for its "influence" recognition. We present a model, derived from the closing operator of mathematical morphology and from the Zobrist's model, which yields very good results for "territory" recognition. Moreover, we give efficient implementations of the dilation operator and territory recognition for computer go. This model was found when developing Indigo, our go playing program, and is now used with success in GnuGo, the go playing program of the Free Software Foundation.

The umbra transform serves as a connection between gray-scale morphology and the classical two-valued morphology of G. Matheron and H. Hadwiger. From a general set-theoretic perspective, the umbra transform of an image (or signal) results in an infinite set, even in the discrete case. By employing bound matrix image representation it is possible to represent the umbra by a finite data structure, the result being an approach that is both intuitive and computational. Moreover, the method is essentially dimensionally independent and thus applies to both morphological image and signal processing.

Today, manufacturing methods are classified into two groups as conventional and non- conventional manufacturing methods. While turning, milling, and drilling are among the conventional manufacturing methods, processes such as laser, plasma, electro erosion, ultrasonic machining and water jet machining are among non-conventional, namely modern manufacturing methods. The cutting tool does not used in modern manufacturing methods. This situation is an advantage. There are some uncertainties on the machining performance of abrasive types, apart from the superior properties of the method. In this study, the effect of different abrasive types on machining performance in abrasive water jet machining (AWJM) was investigated by using computer aided finite element analysis.

Evaluating the integrity of the welded pipes used for fluid transportation in processing industries demands certain investigations on the erosion and corrosion behavior under various environmental conditions. ASTM A106 Grade-B pipes are butt welded using an automated MIG welding setup to obtain the optimum output response such as Reinforcement Form Factor (W1), Penetration Shape Factor (W2), and Tensile Strength (W3) in the weldments. The slurry erosion test is conducted on the weldment surface by varying the velocity and erodent concentration in acidic (0.1M H₂SO${}_4)$ and alkaline (3.5%wt. NaCl) conditions. Correspondingly, the samples are subjected to electrochemical corrosion test in 0.1M H₂SO₄ and 3.5% wt. NaCl solutions. The SEM investigations carried out on the eroded weldment surface show glimpses of erosion mechanisms such as shallow and deep ploughing, oxide cracks, ridges and valleys, scale formation at some areas attributing to sulphide deposition. The corrosion that occurred on the weldment surface tested under acidic conditions is relatively high compared to the alkaline conditions. The reinforcement form factor is the most preferable weld bead characteristic to obtain better erosion and corrosion resistant weldments in the investigated pipe material.

Erosion is the primary concern in gas turbines, power plants, fertilizer plants, jet aircraft and civil aircraft. The military, gas turbine blades are affected by dust clouds ingestion and impingement of slurry particles. In this study, we investigated the erosion rate of Inconel 718 and Ti-6Al-4V turbine blades in the air jet-erosion test rig by ($50\mu$m) silica erodent. The primary process parameters, such as velocity (100 and 150m/s), impingement angle (30–90^∘), feed rate (5–10g/min), temperature (30–650^∘C) and standoff distance (10–50mm) were optimized using response surface methodology (RSM). The design of experiments (DOE) and experimental screening tests were performed to identify the significant process parameters on the erosion of turbine blade materials. To optimize the process parameters, the experiment was conducted to obtain a lowest erosion rate. The ploughing and cutting mechanism of both Inconel 718 and Ti-6Al-4V materials were identified through a scanning electron microscope. As a result, the erosion rate increases with an increase in velocity and temperature; however, the erosion rate decreases with an increase in the impingement angle. The experimental analysis showed that the erosion rate ranged between 0.051–1.914mg/g for Inconel 718 and 0.02–1.0095mg/g for Ti-6Al-4V.

Erosion–corrosion is a common mechanism in the degradation of systems in the mining, chemical, and petrochemical industries. Surface modification can help to reduce the detrimental effects of erosion–corrosion. This study uses the plasma spray process for coating nichrome on duplex stainless steel (DSS2205) to improve the surface characteristics. Erosion tests were performed to analyze the effect of parameters such as impact velocity (150, 175 and 200m/s), impact angle (30^∘, 60^∘ and 90^∘), and erodent particle discharge rate (2.5, 3.75 and 5g/min). According to the findings, the maximum erosion rate ($1.89\times 10^{-6}$g/g) was found at a flow velocity of 200m/s and 30^∘ impact angle with a discharge rate of 2.5g/min. While the minimal erosion rate was observed at a low velocity of 150m/s, 90^∘ impact angle, and 5g/min discharge rate. Electrochemical polarization studies were carried out on the eroded specimens using a corrosive solution containing 3.5% NaCl. Corrosion potentials and current densities were estimated from polarization graphs using the Tafel extrapolation method. The erosion–corrosion properties of the samples were subjected to metallurgical characterization to evaluate the influence of nichrome plasma coatings to assess the potential causes of failure. The grey relational analysis (GRA) was further used for improving the erosion–corrosion process parameters and found the optimum solution as flow velocity of 150m/s, 30^∘ impact angle with a discharge rate of 5g/min. The validation test confirmed an increase of 20–30% in grade when using the optimum process parameters.

Ultrasonic frequency vibration coupled micro-wire electrical discharge machining (UFV-$\mu$ WEDM) has received enormous consideration due to its zero-tolerance machining. Nickel chromium (Ni–Cr) space alloys are a natural choice within the aerospace industry, which are exposed to high temperatures and high pressure, such as turbine seals and exhaust liners. This study reveals the impact of the UFV-$\mu$ WEDM influencing machining parameters like ultrasonic frequency vibration (UFV), servo voltage ($V_S$), time on ($T_{\mathrm{\text{on}}}$), cutting angle ($A_C$), time off ($T_{\mathrm{\text{off}}}$), and current (I) on the Ni–Cr space alloy in terms of minimum surface undulation (Ra) with maximum material removal rate ($M_{\mathrm{\text{RR}}}$). The cutting trials are carried out by central composite design (CCD). Analysis of variance (ANOVA) is used to find out the proportionate contribution of several factors, and it discloses that $V_S$ was the significant parameter impacting Ra (64.57%) and $M_{\mathrm{\text{RR}}}$ (61.86%). The performance sequence of significant influencing parameters is $V_S>T_{\mathrm{\text{off}}}>A_C>T_{\mathrm{\text{on}}}>I$. According to desirability analysis (DA), optimum parameters for numerous solutions are $T_{\mathrm{\text{on}}}=8$$\mu$s, $V_S=50$V, $T_{\mathrm{\text{off}}}=14$$\mu$s, $I=3$A, and $A_C=30^{\circ }$. The optimum conditions lead to the highest $M_{\mathrm{\text{RR}}}$ (5.72mm³/min) and the lowest Ra (3.42$\mu$m). Scanning electron, 3D topography, and atomic force microscope images are used to analyze the machined surface.

This work investigates the piercing of microholes in turbine shroud rings (Inconel-625) using the Abrasive Waterjet Cutting process. The concern with the hole piercing is the kerf angle caused by the attenuation of the jet energy and stand-off distance, which seriously impacts the processing precision of abrasive water jet piercing. The effects of piercing parameters like machining time (40, 60 and 80s), abrasive mesh size (80 mesh and 120 mesh), stand-off distance (1, 2, 3 and 4mm), abrasive jet pressure (100, 125, 150 and 175MPa) are studied to reduce the kerf angle. The kerf angle increased linearly with a stand-off distance increase at different machining times. By piercing for 60s and 80s, the lowest values of kerf angle are obtained (0.03^∘ and 0.02^∘). The optimum conditions for making a pierced hole with a minimum kerf angle of 0.02^∘ were achieved with a machining time- of 60s, abrasive mesh size- of 20 mesh, and abrasive jet pressure- of Scanning electron microscope (SEM) images and visual measuring system (VMS) images are used to identify the surface characteristics in kerf zone. The features, including ploughing, particle embedment, lip impression and wear path due to the ductile mode of erosion caused by high energy impact, is also discussed.

Morphological transformations are commonly used to perform a variety of image processing tasks. However, morphological operations are time-consuming procedures since they involve ordering and min/max computation of numbers resulting from image interaction with structuring elements. This paper presents a new method that can be used to speed up basic morphological operations for binary images. To achieve this, the binary images are first decomposed in a set of non-overlapping rectangular blocks of foreground pixels that have predefined maximum dimensions. Then off-line dilation and erosion of all rectangular blocks are arbitrary obtained and stored into suitable look-up array tables. By using the look up tables, the results of the morphological operations to the rectangular blocks are directly obtained. Thus, first all image blocks are replaced by their look-up array tables. Then the morphological operations are applied only to the limited number of the remaining pixels. Experimental results reveal that starting from a block represented binary image morphological operations can be executed with different types of structuring elements in significantly less CPU time. Using the block representation, we are able to perform dilation 16 times faster than non-fast implementations and 10 times faster than an alternative fast implementation based on contour processing. Significant acceleration is also recorded when using this approach for repeated application of dilation (for 10 iterations, dilation using the block representation is over 20 times faster than non-fast implementations and over four times faster than using the fast contour based approach).