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The purpose of the work is to present issues related to the influence of surface treatment on the strength of adhesive joints of C45 steel sheets by grinding based on experimental research. These issues were related to determining the impact of the gradation and type of abrasive material on the strength of adhesive joints of the steel sheets. The grinding was carried out manually using an angle grinder with a disc diameter of 125 mm and a rotational speed of 11.060 min-1, using abrasive materials with grains made of: ceramics, zirconium and electro-corundum with a gradation of P40, and sandpaper with grains made of electro-corundum with various grain sizes with three gradations P40, P220, P400 (according to European FEPA standards). To make the adhesive joints of steel sheets, the epoxy adhesive was used, which contains an epoxy resin based on bisphenol A and a triethyleneteramine curing agent. A profilographometer from Hommel - Etamic was used to determine selected 2D and 3D surface roughness parameters, and the strength tests of the steel sheets adhesive joints were performed on a ZWICK/ROELL Z150 testing machine. The analysis of the tests showed a significant impact of the surface treatment method on the attained shear strength of the steel sheets adhesive joints. Comparing the samples prepared with electrocorundum of the variable gradation, the tests exhibited that the samples prepared with P40 paper had the highest roughness, while samples prepared with P400 paper had the highest shear strength. Roughness analysis indicated that in the comparison group of samples prepared with abrasives of the various abrasive materials, ceramics showed the highest roughness parameters and the shear strength of the adhesive joints after this treatment. [ABSTRACT FROM AUTHOR]

This article describes the results of studies on the influence of parameters of chemical thermal treatment of copper slag particles on the quality of hydroabrasive cutting. The essence of the synthesis of the silicon carbide diffusion layer on the surface of a copper slag particle in order to create new heavy duty abrasive material is described. Data on the surface quality after hydroabrasive cutting under various modes of chemical thermal treatment have been obtained. [ABSTRACT FROM AUTHOR]

Swirling impeller abrasive water jet (SAWJ) is a viable alternative for larger-diameter drilling of mining and oil and gas extraction. Abrasive material plays an important role in eco-efficient drilling of SAWJ. Here, we investigate performances of six types of abrasive materials during SAWJ drilling of hard granite. Rock breaking performances and abrasive particles characteristics before and after impact were studied. Besides, reusability, efficiency and economy of different abrasive materials were discussed. The results indicated that SAWJ would create a large-diameter (63–71 mm) hole with a conical bulge on the bottom regardless of the abrasive material used in it. Abrasive particles size distribution and shape factor before and after impacting with granite had slight changes. Moreover, median diameter of the particles and shape factor were used for estimating the reusability of the abrasive particles after impacting with granite, and the results indicated that all the abrasive materials had excellent reusability. Besides, the efficiency and economy analyses showed that the garnet abrasive had the best rock breaking performance. Therefore, we recommend garnet as the abrasive during swirling impeller abrasive water jet drilling of granite. Highlights: Performances of six types of abrasive materials during SAWJ drilling of granite. Particle size and shape factor are used to estimate the abrasive materials reusability. Garnet abrasive is recommended as the abrasive during SAWJ drilling of granite. [ABSTRACT FROM AUTHOR]

Purpose. Improving the efficiency of abrasive water jet cutting by choosing rational process parameters and abrasive material. Methods. Full-scale tests within the program of a full-factor experiment on cutting a high-pressure barrel into building structures, statistical data processing. Findings. Experimental data on the time of the high-pressure cutting barrel into building structures made of various materials have been obtained. Application field of research. The research results can be used by fire rescue units in emergency response.

This paper presents the results of the theoretical studies of the process of wear of the technological surfaces of saw gin grates. Mathematical expressions are obtained, with the help of which it is possible to determine the theoretical statistical characteristics of the raw roller and it is indicated that the wear of the grate, in the process of operation from the impact of the raw roller, occurs as a result of the abrasive deposited on it. A rod model of the process of interaction between a raw roller and a grate has also been studied, on the basis of which it is possible to determine the depth of abrasive penetration in the contact surface of the working zone of the grate. The possibility of reducing the wear of grates by increasing the area of their technological surfaces and reducing, due to this, the probability of abrasive grains getting into the same place, is substantiated. A grate with a new convex shape of the technological surface is proposed. Calculations have determined that in this case the service life of the grate increases up to 50%.

The results of the theoretical and experimental studies of the process of producing a porous diamond tool with anisotropic pore structure for grinding and polishing works with flow in the treatment area coolant through the pores of the tool are given. On the basis of the conducted theoretical and experimental studies porous abrasive material, which allows to increase productivity when machining hard more than 65 % is developed.

In the pipe-rolling shop, on the site of preparation of mandrels and disc saws were the centerless turning and grinding complex VT-8 «Hetran» for repair of mandrels are used, studies have been conducted to test experienced grinding belts. The choice was based on a comparative analysis of the work of experienced grinding belts with usual industrial grinding belts. The resistance of grinding belts for one mandrel is calculated. A positive result (economic effect) was obtained by using experienced grinding belts.

In this study, the synthesis and characterization of abrasive polyester composite discs reinforced with apricot kernel shell (AKS) particles and hexagonal boron nitride (BN) were carried out as an alternative to the methods used to remove the surface corrosion from metallic surfaces. Polyester composites were obtained by unsaturated polyester resin as a matrix and AKSs (1%, 3%, 5% and 10% weight ratio) with 200 mesh and 1% BN as reinforcements. Kernel shells as a source of cellulose were used for increasing mechanical stability of abrasive composite discs. The structure and chemical properties of the obtained composites were characterized by Fourier transform infrared spectrometer, X‐ray spectrophotometer and SEM analysis. Their thermal properties were determined by differential thermal analysis, thermogravimetric analysis and differential scanning calorimetry. The synthesized polyester composites were molded into cylindrical discs and the corrosion and paint layer abrasive properties of these discs on different corroded metal surfaces were investigated. The hardness of the prepared abrasive polyester composites were also measured as mechanical properties. The hardness values of prepared abrasive discs were determined as 21.9, 22.1, 23.4, 24.5 and 25.9 ± 0.1 for pure PE, 1%, 3%, 5% and 10% composites, respectively. In addition, the cleaning ability of the abrasive composites on the metal surface was determined by measuring the surface roughness and the amount of peeling. As a result, it has been determined that the most suitable optimum conditions are achieved with a contribution of 10% AKS particles reinforced composite structure considering the features such as cleaned surface roughness, cleaning suitability and composite abrasion. [ABSTRACT FROM AUTHOR]

The article deals with an unconventional way of simulating the erosion of concrete surfaces by means of high-speed water flows. The proposed method allows the use of short-term experiments to predict the future failure of concrete elements in specific concrete mixtures exposed in practice to the action of fast-flowing fluids, whether as regards sewers, overfalls of water reservoirs, inlet channels of retention reservoirs, etc. The article shows results of experiments on disintegration of the surface layer of model concrete test specimens of various physical-mechanical properties that were exposed to various types of high-speed water flows. It has been demonstrated that the application of high-speed water flows significantly accelerates the degradation process of the surface layers. This simulation of the real situation can considerably shorten the time needed for the development and testing of new erosion-resistant construction elements.

Abrasion is a phenomenon in which the reduction of volume and mass of the material surface is caused by friction, scratching and percussion, thus, it is promising to modify the surface characteristics for abrasion resistance enhancement. In this study, polyurea waterproof adhesive (PUA), polyurethane waterproof coating (PUR), iron sheet (IS), and rubber (RB) are applied for surface treatments to improve the abrasion resistance of concrete, and their effects on the mechanical strength, nano-scratch, drop-weight impact and resistance to debris flow abrasion are investigated. The results show that all surface treatment methods improve the flexural strength of concrete, while PUA, PUR and IS surface treatments reduce the compressive strength due to the size effect of concrete. The high-hardness surface treatments (PUA and IS) significantly reduce the abrasion rate due to their excellent resistance to impact and scratches, exhibiting a low roughness after abrasion. Abrasion rate of concretes PUA and IS at 48 h are 0.04 g/h and 0.03 g/h, respectively, which decrease by 75% and 81%, compared to the untreated concrete. The aggregates cutting, micro-cracks, scratches and indentation formation are abrasion failure mechanisms of surface-treated concrete caused by debris flow. PUA and IS surface treatment methods with a suitable thickness are recommended to enhance the resistance to debris flow abrasion of concrete protective structures. • Effects of surface treatment methods on abrasion resistance of concrete are investigated. • The abrasion mechanism is analyzed by nano-scratch, 3D morphology and microstructure. • A thick surface treatment layer is not recommended for abrasion resistance enhancement. • High-hardness surface treatment shows excellent debris flow abrasion resistance. [ABSTRACT FROM AUTHOR]

The physics of grinding is considered in order to explain the difference in machinability of tungstenfree and tungsten steels. The strength of the most common steels and alloys is studied over a broad range of strain rate and temperature. Analysis of the results established the variation in strength of high-speed tungsten-free and tungsten steels in typical grinding conditions and permits explanation of the difference in machinability of the steels in physical terms. The relation between the machinability of steel and wear of the abrasive tool is investigated in experiments with individual grains (plane angle ϕ = 90°) of different abrasive materials: electrocorundum (24A), zirconium corundum (38A), and Elbor (Borazon). That permits the derivation of a regression equation reflecting the qualitative characteristics of the process, such as the starting point, the presence of an extremum, and the asymptotic behavior. [ABSTRACT FROM AUTHOR]

A rational method is considered for utilizing alumina calcining furnace dust containing nanoparticles based on using technogenic alumina dust as a basic abrasive material component for decorative treatment of a natural stone surface. [ABSTRACT FROM AUTHOR]

This paper focuses on the influence of various types of abrasive grains on cutting properties during the grinding process for bearing steel. In this experiment, not only conventional super-hard abrasive materials but also a new type of abrasive material were employed in grinding wheels. The measurement results were compared, and an evaluation was made of the cutting properties of the new abrasive material. The options were then evaluated for their practical applicability. The measurement results indicated that a grinding wheel with Abral and SG grains is the most suitable for grinding hardened bearing steel in order to achieve the best roughness and geometrical accuracy.

Abstract: Light weight aluminum has shown high applicability in the automobile industry for high fuel efficiency. However, the manufacturing of aluminum is limited by the deburring process owing to the difficulty in employing wet blasting. In this paper, we present experimental and computational studies on the deburring process of wet blasting for aluminum. The process conditions are analyzed to achieve high deburring performance that minimizes the surface damage. Parameters of wet blasting with a significant influence on the deburring process are investigated and a promising deburring technique for aluminum is proposed. [Copyright &y& Elsevier]

The global environmental trends lead to utilizing of so called „clean technologies"with minimum environmental impact. In case of high-speed continual waterjets application it is possible to expect substantial raise of products manufacturing efficiency. The analysis of the system of separating and recycling abrasive material from a fluid in abrasive water jet cutting process was the aim of the research. The research has been conducted with process condition, environmental approaches and high effectiveness of the technology. [ABSTRACT FROM AUTHOR]

The article presents a study on the reactivity of titanium with abrasive materials and its polishing. It highlights the high reactivity of titanium with abrasives in which the grinding temperature influencing titanium-abrasive reactions should be kept from rising. It suggests that since polishing is also a procedure of abrasive cutting, inhibition of titanium-abrasive reaction is an important key to efficient polishing.

The aim of the research was to investigate changes of abrasive grains on metals observing the kerf walls produced by the Abrasive Water Jet (AWJ). The microscopy observations of the sidewalls of kerfs cut by the AWJ in several metal materials with an identical thickness of 10 mm are presented. The observed sizes of abrasive grains were compared with the results of research aimed at the disintegration of the abrasive grains during the mixing process in the cutting head during the injection AWJ creation. Some correlations were discovered and verified. The kerf walls observations show the size of material disintegration caused by the individual abrasive grains and also indicate the size of these grains. One part of this short communication is devoted to a critical look at some of the conclusions of the older published studies, namely regarding the correlation of the number of interacting particles with the acoustic emissions measured on cut materials. The discussion is aimed at the abrasive grain size after the mixing process and changes of this size in the interaction with the target material.