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The paper's aim is to investigate the sand slurry erosive wear behaviour of Ni‐Cr‐Si‐B coating deposited on mild steel by flame spraying process under different test conditions.

Flame sprayed coatings of Ni‐Cr‐Si‐B were developed on mild steel substrate The slurry pot tester was used to evaluate wear behaviour of the coating and mild steel. The erosive wear test was conducted using 20 and 40 per cent silica sand slurry at three rotational speeds (600, 800 and 1,000 rpm).

Slurry erosive wear of the coating showed that in case of 20 per cent silica sand slurry weight loss increases with increase in rotational speed from 600 to 1,000 rpm while in case of 40 per cent silica sand slurry weight loss first increases with increase in rotational speed from 600 to 800 rpm followed by marginal decrease in weight loss with further increase in rotational speed from 800 to 1,000 rpm. Increase in wear resistance due to thermal spray coating of Ni base alloy on mild steel was quantified as wear ratio (weight loss of mild steel and that of coating under identical erosion test conditions). Wear ratio for Ni‐Cr‐Si‐B coating was found in range of 1.4‐2.8 under different test conditions. The microstructure and microhardness study of coating has been reported and attempts have been to discuss wear behaviour in light of microstructure and microhardness. Scanning electron microscope (SEM) study of wear surface showed that loss of material from the coating surface takes place by indentation, crater formation and lip formation and its fracture.

It would assist in estimating the erosion wear performance of flame sprayed Ni‐Cr coatings and their affects of wear resistance.

Erosion wear of flame sprayed coatings in sand slurry media medium is substantiated by extensive SEM study.

The purpose of the paper is to explore the structural feasibility of substituting traditional thick joint mortars with earth slurry mortars modified with varying amounts of sand. Thin jointing of earth blocks would reduce the cost of sustainable earth construction.

Compressive strength of earth‐block cubes was determined. Flexural strength was measured using the BRE electronic bond wrench, which enables block couplets to be tested quickly and accurately. Three samples of earth block, one from southwest England and two from East Anglia, together with nine examples of earth slurry mortar jointing were studied, including the effect of reinforcing the joint and or the block using hessian.

The 28‐day cube characteristic compressive strengths were determined for Appley soil, Norfolk lump and Beeston soil, the last with 0 per cent sand, 25 per cent sand and with 25 per cent sand with hessian. The flexural strengths of Appley and Beeston earth slurries were determined, along with Thermalite thin jointed cement and cement mortar for comparison. The Beeston soil flexural strength increased with increasing sand content. Earth slurry with 40 per cent sand and hessian present in the joint gave the greatest strength. It is important to use blocks and slurry mortars of the same soil. Extruded and compressed earth blocks are best suited to slurry jointing.

This work successfully demonstrates the structural feasibility of carefully reducing the thickness of earth mortars when constructing sustainable earth block walling. Characteristic flexural strengths are suggested where the test results were sufficiently consistent, and of a magnitude likely to be useful in design.

This paper aims to the transportation of high concentration slurry through pipelines that will require thorough understanding of physical and rheological properties of slurry, as well as its hydraulic flow behavior. In spite of several contributions by the previous researchers, there is still a need to enrich the current understanding of hydraulic conveying through pipeline at various flow parameters. The pilot plant loop tests, particularly at high concentrations, are tedious, time-consuming and complex in nature. Therefore, in the current research the prediction methodology for slurry pipeline design based on rheological model of the slurry is used for calculation of pressure drop and other design parameters.

It has been established that slurry rheology plays important role in the prediction of pressure drop for laminar and turbulent flow of commercial slurries through pipeline. In the current research fly ash slurry at high concentration is chosen for rheological analysis. The effect of particle size and solid concentration is experimentally tested over the rheological behavior of slurry and based on the rheological data a correlation is developed for calculation of pressure drop in slurry pipeline.

The present study strongly supports the analytical approach of pressure drop prediction based on the rheological parameters obtained from the bench scale tests. The rheological properties are strongly influenced by particle size distribution (PSD), shear rate and solid mass concentration of the slurry samples. Pressure drop along the pipeline is highly influenced by flow velocity and solid concentration. The presence of coarser particles in the slurry samples also leads to high pressure drop along the pipeline. As the concentration of solid increase the shear stress and shear viscosity increase cause higher pressure drop.

The transportation of slurry in the pipeline is very complex as there are lot of factors that affect the flow behavior of slurry in pipelines. From the vast study of literature it is found that flow behavior of slurry changes with the change in parameters such as solids concentration, flow velocity, PSD, chemical additives and so on. Therefore, the accurate prediction of hydraulic parameter is very difficult. Different slurry samples behave differently depending upon their physical and rheological characteristics. So it is required to study each slurry samples individually that is time-consuming and costly.

Nowadays in the world, long distance slurry pipelines are used for the transportation of highly concentration slurries. Many researchers have carried out an experiment in the design aspects of hydraulic transportation system. Rheological characteristics of slurry also play crucial role in determining important parameters of hydraulic conveying such as head loss in commercial slurry pipeline. The current research is useful for the prediction of pressure drop based on rheological behavior of fly ash slurry at various solid concentrations. The current research is helpful for finding the effect of solid concentration and flow velocity on the flow behavior of slurry.

Slurry pipeline transportation has advantages over rail and road transportation because of low energy consumption, economical, less maintenance and eco-friendly nature. Presently majority of the thermal power plants in India and other parts of the world dispose of coal ash at low concentration (20 per cent by weight) to ash ponds using the slurry pipeline. Transporting solids in slurry pipelines at higher concentrations will require a thorough knowledge of pressure drop. In the current research a rheological model is proposed for prediction of pressure drop in the slurry pipeline, which is useful for optimization of flow parameters.

All the experimental work is done on fly ash slurry samples collect from the Jharli thermal power plant from Haryana State of India. Bench scale tests are performed in the water resource laboratory of IIT Delhi for physical and rheological analysis of slurry. It has been shown in the results that up to solid concentration of 50 per cent by mass all the samples behave as non-Newtonian and follows a Herschel–Bulkley model with shear thickening behavior. In the present research all the result outcomes are unique and original and does not copied from anywhere.

The purpose of this study is to analyze the slurry erosion failure of Ni-20Cr (Ni-Cr₂O₃), Ni-20Al (Ni-Al₂O₃) and Al-20Ti (Al₂O₃-TiO₂) coatings deposited on SS316L by the high-velocity oxy-fuel process.

Slurry erosion experiments were conducted using a pot type erosion tester at different velocities 1.81, 2.71, 3.61 and 4.59 m/s for the time duration of 90-180 minutes. Fly ash and bottom ash were used as erodent media; the concentration of mass flux was taken as 30-60 wt. per cent. Artificial neural network (ANN) method was used to simulate the slurry erosion for thermally sprayed coatings.

Slurry erosion of coatings increases non-linearly with an increase in experimental durations, mass flux and velocity. Slurry erosion of Ni-20Cr and Ni-20Al layers was found to be maximum at 60° impingement angle, whereas 30° for SS316L and 45° for Al-20Ti coating. Slurry erosion performance of SS316L was improved by 2.56-3.19 times by depositing Ni-20Cr and Ni-20Al layers, whereas it improved 1.15-1.75 times by Al-20Ti coating. The slurry erosion SS316L was found almost 1.35 ± 1.28 times greater than that of the Ni-20Al coating, whereas it was to be 1.12 ± 1.36 times greater than Al-20Ti. Ni-20Al-coated SS316L showed a lower value of slurry erosion than Al-20Ti-coated SS316L.

Stainless Steel SS316L is widely used in hydraulic machinery (such as turbines, pumps, valves, fittings, etc.) of hydraulic and thermal power plants, chemical industry and marine industry. Therefore, the deposition of ductile and brittle coatings is a better option for their durable performance.

Erosion wear of Ni-20Cr, Ni-20Al and Al-20Ti coatings was successfully simulated by using an artificial neural network model by supplying experimental data as a target.

The purpose of this paper is to explore the factors that affect the compactness of the mud filter cake, so as to prepare diaphragm wall slurry with good uniformity, small filtration loss and excellent recycling performance.

In this paper, the thickness, filtration loss and slurry viscosity of the filter cake are used as the characterization methods. The effects of pore depth, slurry specific gravity, intercalated metal ions, bridging polymer and water-soluble polymer on the compactness of the filter cake were studied.

The experimental results showed that the slurry's own pressure (pore depth) and specific gravity have little influence on the compactness of the filter cake and K⁺ can be considered as an auxiliary filtration loss reduction factor. Both the sulfonate copolymer and the potassium polyacrylate particle can significantly reduce the filtration loss of the slurry, which can effectively improve the filter cake compactness. Moreover, the composite application of potassium polyacrylate particles in the sizes of 80–100 and 150–200 meshes can exhibit a better filter cake compaction effect.

It solves the problems of high pulping cost, serious pollution of the environment, poor quality of filter cake formation and large filtration loss during the construction of the diaphragm wall, which improved the construction quality of the diaphragm wall.

This paper aims to deal with the study of effect of cerium oxide (CeO₂) modification on the sand slurry erosion resistance of Ni – tungsten carbide (WC) coatings.

Flame-sprayed conventional and CeO₂-modified Ni–WC coatings were developed on a mild steel substrate. Slurry erosion tests were carried out in an in-house-designed and fabricated pot-type slurry erosion test rig to evaluate wear behavior of conventional and modified coatings. The erosive wear test was conducted using 5 per cent silica sand slurry at 850 rpm.

Modified coatings exhibited increased hardness as compared to the conventional coating. Slurry erosion resistance of most modified coatings was superior to that of the unmodified coating. Hardness of coating doped with 0.9 per cent CeO₂ was highest among all coatings, and concomitantly this composition also showed the least wear. Scanning electron microscopy (SEM) revealed that microcutting was much less in the modified coating.

Slurry erosion wear of Ni–WC flame-sprayed coatings in sand slurry media is substantiated by extensive SEM study.

Chemical mechanical polishing (CMP) has attracted much attention recently because of its importance as a nano-scale finishing process for high value-added large components that are used in the aerospace industry. The paper aims to discuss these issues.

The characteristics of aluminum nanoparticles slurry including oxidizer, oxidizer contents, abrasive contents, slurry flow rate, and polishing time on aluminum nanoparticles CMP performance, including material removal amount and surface morphology were studied.

Experimental results indicate that the CMP performance depends strongly on the oxidizer, oxidizer contents, and abrasive contents. Surface polished by slurries that contain nano-Al abrasives had a lower surface average roughness (Ra), lower topographical variations and less scratching. The material removal amount and the Ra were 124 and 7.61 nm with appropriate values of the process parameters of the oxidizer, oxidizer content, abrasive content, slurry flow rate and polishing time which were H₂O₂, 2 wt.%, 1 wt.%, 10 ml/min, 5 min, respectively.

Based on SEM determinations of the process parameters for the polishing of the surfaces, the CMP mechanism was deduced preliminarily.

This paper aims to cover all the aspects of development, investigation and analysis phases to evaluate the slurry erosion performance of test coatings. The powders having composition of Ni-20Al₂O₃ and Ni-15Al2O₃-5TiO₂ were deposited on CA6NM grade turbine steel by using high velocity flame spray (HVFS) technique. The characterization of the coatings was done with the help of SEM/EDS and XRD techniques. Various properties such as micro-hardness and bonding strength of the coatings were also evaluated. Thereafter, these coatings were subjected to an indigenously developed high speed slurry erosion tester at different levels of rotational speed, erodent particle size and slurry concentration. The effect of these parameters on the erosion behavior of coatings was also evaluated. The slurry erosion tests and SEM of the eroded surfaces revealed remarkable improvement in slurry erosion resistance of Ni-15Al₂O₃-5TiO₂ coating in comparison with Ni-20Al₂O₃ coating.

Two different compositions of HVFS coating were developed onto CA6NM steel. Subsequently, these coatings were evaluated by means of mechanical and microstructural characterization. Further, slurry erosion testing was done to analyze the erosive wear behavior of developed coatings.

The coatings were successfully developed by HVFS process. Cross-sectional microscopic analysis of sprayed coatings revealed a continuous and defect-free contact between substrate and coating. Ni-15Al₂O₃-5TiO₂ coating showed higher value of bond strength in comparison with Ni-20Al₂O₃ coating. Under all the testing conditions, Ni-15Al₂O₃-5TiO₂ coatings showed higher resistance to slurry erosion in comparison with Ni-20Al₂O₃ coatings. Rotational speed, average particle size of erodent and slurry concentration were found to have proportional effect on specific mass loss of coatings. The mixed behavior (brittle as well as ductile) of the material removal mechanism was observed for the coatings.

From the literature review, it was found that researchers have documented the various studies on Ni-Al₂O₃, Ni-TiO₂ and Al₂O₃-TiO₂ coatings. No one has ascertained the synergetic effect of Alumina and Titania on the slurry erosion performance of Nickel-based coating. In view of this, the authors have developed Ni-Al₂O₃ and Ni-Al₂O₃-TiO₂ coatings, and an attempt has been made to compare their mechanical, microstructural and slurry erosion characteristics.

The purpose of this paper is to synthesize a polyacrylate-based dispersant with a determined target molecular weight for oily systems and to determine the optimal dispersant level and monomer ratio of the dispersant.

The dispersant was synthesized by conventional radical polymerization using methacrylic acid, butyl acrylate and dimethylamino ethyl methacrylate as the monomer. It was characterized by Fourier transform infrared spectroscopy, nuclear magnetic hydrogen spectroscopy, gel permeation chromatography and thermogravimetric analysis. The dispersant was used to disperse TiO₂, and the performance of the dispersant was evaluated by measuring the viscosity, particle size and dispersive force of the slurry.

The dispersant exhibited high thermal stability and was successfully anchored to the surface of the TiO₂ pigment. When used to disperse a TiO₂ slurry, it effectively made the TiO₂ slurry more fluid, indicating its strong viscosity-reducing properties. The viscosity, particle sizes and dispersion capabilities of the TiO₂ slurry were found to vary depending on the contents and monomer ratios of the dispersant.

P(MAA-BA-DM) dispersant increases the wettability of TiO₂ only in oily solvents but not in aqueous solvents.

P(MAA-BA-DM) dispersant makes it easier to disperse TiO₂ pigments in oily solvents, increasing the amount of pigment in the solvent and making the preparation of highly pigmented pastes easier.

A dispersant containing suitable carboxyl and tertiary amine groups was initially synthesized to disperse TiO₂ in an oily system. The findings are anticipated to be used in the formulation of pigment concentrates, industrial coatings and other solvent-based coatings.

This paper aims to clarify the relationship between the slurry erosion and one of the case hardening treatments, i.e. boronizing in this study, for AISI-5117 steel alloy. AISI-5117 steel alloy was used because of its variety applications in the field of submarine equipment. Most of the slurry erosion factors such as velocity, impact angle and mechanism of erosion were studied at different impact angles.

At first, the samples were prepared and subjected to the boronizing treatment in controlled atmosphere. By using a slurry erosion test-rig, all experiments for studying the slurry erosion factors were carried out. Moreover, the studied specimens were investigated via scanning electron microscope, optical microscope and X-ray diffraction to study the erosion mechanism in the different conditions.

It was expected that the boronization of the AISI-5117 steel would increase its slurry erosion resistance due to its positive impact on the surface hardness. However, the results observed show the opposite, where the boronization of AISI-5117 steel decreased its slurry erosion resistance as implied by the increase of the mass loss percentage at all impact angles.

This research, for the first time, exhibits the effect of boronizing treatment on the slurry erosion in different impact factors accompanied by the erosion mechanism at each impact angle.