Search

Distribution of the maximum undeformed chip thickness can be approximated as the reproduction of grooves and protrusions of the grinding surface. It plays a very important role in grinding process as it has a close influence on the prediction and modeling of grinding forces, tool life, and surface quality, as well as process stability. In this study, it is investigated from the perspective of the real interference depth of the active abrasive grain to cater to the performance evaluation of the grinding surface. Firstly, image processing techniques combined with three dimensional topography tests are utilized to extract grains' essential characteristics such as the protrusion height, shape, distribution and density. Then, grains' wear is quantified by the probability assignment function and Dempster-Shafer evidence theory. Based on this, the actual interference depth of a single grain is determined. Through grain's kinematics analysis and considering the effect of contact deformation on the actual contact arc length and affective cutting edge density, the distribution of chip thickness in the current grinding area is defined and its distribution model is established. Model's correctness and rationality are verified by grinding experiments of the slider raceway. Results demonstrate the grain's interference depth highly depends on its protrusion height, wear amount and grinding depth which is a primary contributor to the size of undeformed chip thickness, and grains' density, contact deformations mainly affect its distribution. The quantified distribution model of the maximum undeformed chip thickness lays a foundation for the topography modeling and integrity research of grinding surfaces.

The abrasive grains contained in the engine lubricant can not only characterize the quality of the lubricant used, but also indirectly characterize the technical status of the machine operation. Therefore, the detection of abrasive particles in engine lubricants can not only find the quality changes of lubricants, is conducive to the realization of “oil on demand”, reduce costs, but also through the detection of lubricant mill particles to predict machine failure, to ensure the safe operation of the machine. Monitoring the state of lubricants, not only can timely find changes in the quality of lubricants, so that on-demand replacement of lubricants, reduce operating costs, more important is that the grinding grain in the lubricant contains important machine status information, through the oil mill particle detection information can predict the technical status of the machine in advance, and then timely detection of signs of failure and forecast equipment may occur, targeted maintenance and repair.

As a key component of an aero-engine, the blisk has the characteristics of complex structure and difficult processing of materials. The quality of its processed surface has a vital impact on the overall performance of the aero-engine. However, at present, most blisks are polished manually, which has low polishing efficiency and difficulty in ensuring the consistency of polishing quality. Therefore, this paper analyzes the process of the robot abrasive belt grinding of the blisk and carries out relevant experiments to verify it. The experimental results show that: compared with manual polishing, the polishing efficiency is increased by 1.5 times; the blisk blades after polishing have good consistency, the milling cutter lines are effectively removed; the surface roughness can reach Ra0.24 μm, the smooth transition of the polishing area does not hurt and the blisk body; the robot belt grinding technology can meet the grinding requirements of the blisk.

Process parameters are important factors affecting cutting efficiency. In order to get the best process parameters and improve the cutting efficiency, the relationship between the process parameters and cutting efficiency is studied and analyzed in this paper. Cutting efficiency can be expressed by the volume of material removed per unit time. At the beginning of the jet, the width of the slit is equal to the diameter of the abrasive nozzle. Then the cutting depth can represent the cutting efficiency.

According to the relevant theory of metal cutting of finite element analysis, the finite element model of micro cutting process is established with titanium alloy Ti6Al4V to study the ultrasonic assisted magnetic abrasive finishing (UAMAF). The distribution and variation of stress and temperature field and chip formation are analysed. The results show that the stress and temperature of the contact area increase with the indentation depth, and the temperature and stress reach maximum when the indentation depth reaches the maximum. Meanwhile, the thickness and width of undeformed chip increase with the indentation depth.

One of the main technological operations in the production process is the cutting operation. Due to the use of various materials, with different properties and shapes, cutting of materials with a water-abrasive jet is increasingly competing with traditional processing methods. The quality of cutting operations is important for technological, operational and work safety reasons. One of the methods that allows for the simultaneous improvement of the geometrical condition of the surface layer and the elimination of sharp edges, processed after cutting with an abrasive water jet, especially in the area of the material jet exit, is brushing the surface with ceramic brushes. The aim of the work is to analyze the possibility of surface treatment of the EN-AW 7075 aluminum alloy used in the aviation industry after cutting with a water-abrasive jet and to determine the effect of ceramic brush processing conditions on the surface quality. A significant influence of the number of passes and the type of ceramic fiber of the brush on the surface roughness after brushing was demonstrated.

The paper presents assessment of the mass wear of an airport baggage belt conveyor system. Results of abrasion resistance determined by the Schopper-Schlobach method in compliance with the PN-ISO 4649: 2007 are presented. Typical wear modes of belt conveyors are described, and the areas of high abrasive wear are identified. The preparation of test samples is presented, conducted tests and test stands used in the study are described. Obtained results are statistically processed, and the relationship between mass wear and sampling location is established. It has been found that the mass wear in contact zones of the baggage carousel segments differs to a significantly for the different friction points.

The cleaning of PV-module glass to remove soiling and other contaminants can alter the surface physical and optical properties. To assess the impacts of mechanical cleaning, we examined the effects of several PV-cleaning processes used in Brazil PV installation. Specifically, we evaluated modules and module glass covers that were exposed to natural soiling during a 90-day period and cleaned twice daily. With this accelerated timeframe, a controlled artificial soiling method was used to mimic the local soiling conditions. The surface roughness, optical transmittance, and PV-panel short-circuit current (I sc ) were measured at regular intervals during the cleaning processes. The cleaning techniques included water spraying, compressed air, brushes with various bristles used in the field (thick nylon, soft-thin nylon, silicone foam) with water, polyurethane sponge with water, and abrasive synthetic resin sponge with water, and rubber squeegee to remove the water. For this region in Minas Gerais, Brazil, (characterized by moderate soiling conditions during the dry season), the water-only and compressed-air techniques provided the best results, with minimal detected damage to the surfaces and changes in the measured I sc after the 90-day period of experiment. The methods using the synthetic brushes were the most harmful to the glasses. For situations of higher dirt adhesion (e.g., caking) or thicker soiling layers on the module glass, the methods with a nylon brush and polyurethane bushing were more effective.

Ultra-thinning of 20 nm-node DRAM wafers down to 3–5 µm was demonstrated for bumpless Wafer-on-Wafer (WOW) applications. Two different types of thinning process, namely, grinding (#2000 grit abrasive) and chemical mechanical polishing (CMP), were carried out in order to evaluate the relationship between device characteristics and the features of defects on the back side, as well as the influence of Cu contamination. No obvious degradation of the retention characteristics occurred even when the Si thickness was reduced to 3 µm, regardless of the thinning process used. The grinding-finished surface showed better gettering ability than that of CMP. The standby current increased by more than 15-times when the Si thickness was reduced to 4 µm by grinding, whereas the current increased by only 2.7-times in the case of CMP. This suggests that the standby current is strongly dependent on the thinning process. Probable degradation mechanisms are also discussed.

The blisk is a key component of aero engines, and its surface processing quality directly affects the service performance of the aero engine. In using the new open belt grinding process, different degrees of vibration will occur, and they seriously affect the dimensional accuracy and surface quality of the blisk-blade profile. In view of the above-mentioned problems, this paper first built the physical model for the blisk-blade abrasive belt grinding and analyzed the weak stiffness characteristics of the blisk-blade abrasive belt grinding system. Then, based on the kinetic analysis method, the grinding mechanism of the abrasive belt of the blisk-blade was studied, and the process parameters and stability grinding conditions affecting the grinding stability of the blisk-blade belt were analyzed. In addition, the grinding process of the blisk-blade profile belt was simulated by a numerical method. The influence of different process parameters on the grinding vibration of the blisk-blade was quantified, and the optimal combination of process parameters was obtained. Finally, the feasibility of process parameter optimization was verified experimentally. Studies have shown that the weak stiffness of the blisk-blade grinding system always runs through the entire grinding process, but the impact size has a primary and secondary order. The grinding vibration of the blisk-blade belt is related to the process parameters, such as the grinding positive pressure, the belt speed, the feed rate, and the contact wheel hardness. The primary and secondary orders of each influencing factor are grinding positive pressure, belt speed, feed rate, and contact wheel hardness. The optimal combination of various factors was obtained: belt speed vb = 3 m/s, grinding positive pressure Fn = 4 N, feed rate vg = 0.6 m/s, and contact wheel hardness Hs/A55. Through the sand belt grinding verification experiment on the blisk-blade, the grinding belt grinding quality of the blisk-blade surface roughness and blade profile precision is improved after the process optimization.

Nowadays, the fabrication of ultra-smooth surface play critical roles in, integrated circuits (IC) manufacturing, especially for semiconductor substrate materials of silicon, silicon dioxide and silicon carbide wafer. To efficiently production ultra-smooth semiconductor wafer surface, a novel Disc Hydrodynamic Polishing (DHDP) process is proposed. In DHDP process, the polishing slurry was injected from the center of polishing tool and a screw pressure groove was designed on the polishing pad. Then, the fluid film will be formed between the disc polishing pad and the wafer surface, under the high rotation speed and applied load of disc polishing tool. In the fluid film, the particles were droved by the hydrodynamic pressure and shear stress impact the wafer workpiece. The abrasive particles erode the workpiece under the hydrodynamic pressure in the fluid film. Then, the effect of tool speed and machining time on the quality of surface is studied, through a series of experiments. The rotational speed of polishing tool can improve the surface quality. The surface of fused quartz glass wafer surface roughness(Ra) could reach 0.7nm and the peak value(PV) is 8.9nm, which was polished by DHDP process. Moreover, DHDP process can efficiently reduce the surface roughness and acquire ultra-smooth surface for semiconductor wafer.

Sapphire substrate is the most commonly used in semiconductor industry for GaN-based light emitting diodes (LEDs). Chemical mechanical polishing (CMP) is one of the most effective methods to achieve atomic-scale smooth surface. Sapphire is very difficult to process due to its brittleness and high hardness. In order to improve the processing efficiency of sapphire CMP, ZnO was used as an additive in this paper. Because of the insolubility of ZnO in the slurry, the effect of ZnO on the removal rate is not obvious. Through the preparation process optimization of mixing surfactant, deionized water and ZnO with ultrasonic dispersion, the dispersion effect of ZnO in sapphire slurry was obviously enhanced, and the CMP processing efficiency of sapphire substrate was effectively improved. Meanwhile, the action mechanism of ZnO was investigated in depth.

In this paper, the effects of abrasive particle size, polishing pressure and polishing head speed on the removal rate of lithium tantalate(LT) wafer were discussed. The results show that the removal rate of LT wafer is closely related to the abrasive particle size and process parameters. When the particle size is 60 nm, the polishing pressure is 2.5 psi, and the polishing head speed is 50 r/min, the material removal rate(MRR) and surface polishing effect of LT wafer are higher.

The service life of journal bearing depends on the frictional behaviour of its components. The mechanical components failed due to the wear, oxidation, and corrosion phenomena. In this paper, the effect of the normal load, materials hardness and the sliding velocity on the wear and friction are presented. Based on the L16 orthogonal array of Taguchi analysis and ASTM G99 standard, the sliding wear and friction test were conducted. The loads 5 N to 20 N, the sliding velocity 0.1 ms−1to 0.75 ms−1, the counter materials brass (60 BHN), mild steel (130 BHN) against austenitic stainless steel 316L and dry, wet operating conditions at room temperature were used for the experimentation. The parameter's impact on the wear rate were investigated using analysis of variance (ANOVA). Based on the wear rate and coefficient of friction, the normal load, sliding velocity, material hardness difference, and operating conditions were ranked. The worn track morphology and the experimental results were correlated. The wear-track microstructure was analysed with a scanning electron microscope (SEM) to identify the wear mechanism. The adhesive and abrasive wear are found to be primary wear mechanisms.

Nowadays, robot arms are gradually widely used in the plumbing industry due to the severe problem of labor shortage. When using robot arms to conduct the grinding process, the belt wear occurs gradually and affect the workpiece quality. In order to keep the same workpiece quality, a belt speed control system is proposed. The proposed model can compute the wear condition of the abrasive belt, judge the moment to change a new belt, and control the belt speed to maintain the same workpiece quality. Experimental results showed that the coefficient of determination of the model are all higher than 0.878, and when the belt wear affects the workpiece quality, the proposed system can update the new belt speed to ensure the workpiece quality the same within 3 rounds control.

Pre-stressed Hardening Grinding (PSHG) can control the residual stress after grinding, and its surface layer has impacting hardening effect besides the well-known quenching hardening effect due to the impact of abrasive grain. In order to study its impacting hardening effect, the paper established residual stress model and the impacting hardening model of PSHG using ANSYS simulation method considering the main factors of grinding impacting. The variation laws and mechanisms of the residual stress and the impacting hardening layer along with the grinding parameters is revealed. They increase with the increase of pre-stress and the grinding depth due to their comprehensive effect of thermal and strain.

The composition, structure, hardness and wear resistance of periodic multilayer metal/nitride coatings deposited from a filtered vacuum-arc plasma using $\mathrm{T}\mathrm{i}_{0.47}\mathrm{A}1_{0.51}\mathrm{Y}_{0.02}$ cathode by the PIII& D method were investigated. The coating period was changed in the range of 35-300 nm by changing the duration of the periodic feeding (pumping) of nitrogen into the vacuum chamber. The mechanical characteristics of multilayer metal / nitride and single-layer nitride coatings are compared. Single-layer nitride coatings are characterized by a fairly high hardness of 34-36 GPa. The hardness of the multilayer coatings is lower and decreases from 24 to 19 GPa with decreasing period of the composition. The introduction into the composition of nitride coatings of more plastic metal layers does not increase the criterion H/E, which is in the range of 0.07 to 0.09. Due to the high hardness, single-layer coatings have high resistance to abrasive wear, but are destroyed by cavitation due to cracks and pitting peels. Multilayer coatings were slightly better in the cavitation test due to the less pronounced columnar structure, but do not withstand abrasive effects.

A disc cutter is the main breaking rock tool on the cutterhead of the full face hard rock boring machine. It directly contacts the rock and undergoes significant wear and tear. The disc cutter loses the capacity to break rock when it reaches its wear limit, so its construction efficiency can be improved if its degree of wear and tear can be predicted. In this paper, friction work is computed based on the principle of conservation of energy, and the effects of friction on the abrasive volume of the disc cutter are studied. A predictive model of friction work and the abrasive volume of the disc cutter is established, and the influence of the excavation parameters, geometric parameters, and geological parameters on the disc cutter’s wear and tear is analyzed. Several TB880E disc cutters were tested, and the results show that the incremental friction work and the incremental abrasive volume of the disc cutter are proportional when the friction work reaches a certain value. The error of the predictive model of the disc cutter’s wear loss is less than 9%, which proves that the prediction model is reliable and can guide tunnel construction.

Ceria abrasive particles can polish oxides through both mechanical and chemical means. Standard metal polishing occurs through the addition of oxidizing agents to form weaker oxide films that are easier to remove mechanically by silica particles. By replacing this silica with ceria, ruthenium removal rate and roughness can be improved while lowering both the oxidizing agent and abrasive concentration.

The paper describes different industrial workpieces with innovative shape, based on the triangle and tetrahedron Reuleaux, which provides a larger contact surface with the treated material. Innovative milling bodies and lifters, abrasive bodies and nails are presented. The advantages and fields of application of the considered workpieces are discussed. The innovative shape gives energy efficiency and better quality of the production. Also new Braiile screen for visually impaired people and reenigeering of industrial robots are described.

The article deals with the issues of improving the quality of abrasive waterjet machining of metals and alloys using CNC equipment. The development and implementation of automated control system for the grade and thickness of the processed material reduces the number of manufactured products of inadequate quality by staged control of workpiece parameters immediately before abrasive waterjet machining. As a result of the study, a block diagram of an automated control system for material grade and thickness and an algorithm for the operation of the automated control system were proposed, and the constituent elements of this system were selected.

Aiming at the catastrophic consequences of large mechanical equipment due to problems with the lubrication system, a study based on an improved Otsu algorithm is proposed. This article elaborates the significance of online monitoring of abrasive particles in oil and the methods to achieve online monitoring. On the premise of the research of traditional Otsu algorithm, the existing algorithm is analyzed and improved. The experimental part is based on MATLAB simulation link to model and analyze oil abrasive grains. The experimental results show that the designed oil abrasive grain detection algorithm can meet the requirements of stable and effective detection of abrasive grain size and quantity and can distinguish quantitatively. 100um abrasive particles, and the detection rate is not less than 80%, and the performance is good, which meets the design requirements.

Industrial robots have been applied in labor-intensive and high-risk jobs such as grinding, polishing, deburring, etc. However, traditional robotic manufacturing systems require skillful experts to advise the robot programming for controlling manufacturing efficiency and quality. Based on the level of automation, an advanced cyber-physical robot grinding system has been developed to increase efficiency, improve quality, and save human effort. The proposed system consists of robot trajectory generation and optimization, force-based trajectory modification, vision-based grinding machine localization, and acoustic emission based abrasive belt wear-life analysis. Compared with traditional robot tuning processes, the process quality of the proposed system is better than that, and the tuning time is shortened from 14 days to 1-2 days.

Belt grinding is a commonly used finishing process that can reduce defects and burrs created by previous machining procedures. While it has been studied for a long time, researchers have mostly focused on methods that use grinding wheels, while other methods have seldom been addressed. Aiming to develop a force-sensorless grinding system, we propose a new 3-dimensional (3D) model that estimates the normal force being generated between workpieces and the grinding belt with a free strand of abrasive belt. The 3D model was constructed using integrated 2D interaction forces between the workpieces and the abrasive belt, and the latter force derived based on the tension force of the abrasive belt and the geometric contact configuration. A virtual simulator was developed and added to the geometric-based digital twin of the grinding system, forming a physics engine. The model was experimentally evaluated using spheres, cylinders, and frustums grinding specimens. The results confirm that the model can successfully predict normal forces.

Sensory properties of diamond-based HBAR were investigated by means of the Al, Sc, Mo and Pt thin and ultrathin film deposition. First the operational frequency ∼20 GHz of a sensor having a comparatively high $Q$ factor was applied with an aim decreasing the relative measurement error and increasing the sensitivity. Sensitivity on Pt film deposition was estimated as 0.5 nm. Dependences of the overtone's frequency shift vs. film thickness could be differed from the linearly proportional ones. Such peculiarities were explained in terms of an acoustic impedance difference between the films and diamond substrate. Experimental results were in close accordance with FEM model data. Prototypes of sensory elements developed have the important advantages over all other types of acoustoelectronic sensors owing to operating the SHF band up to 20 GHz, high chemical and biological inertness of the working diamond surface, resistance to the temperature load, abrasive wear resistance, and the possibility of a multiple-time application. Investigated diamond-based 5th layered piezoelectric structure should be considered as a prospective platform creating a number of new generation sensors.

Colloidal stability is a basic requirement for CMP slurry to have stable performance. Due to its high density and high gravity pulling force, ceria particles in CMP slurries cannot be suspended homogenously in static state for long period of time. Improperly mixing can result in changing in CMP performance due to inhomogeneous distribution of ceria particles at different layers of slurry tank. In this work, we collect experimental data how different size of ceria particles and concentration affects the settlement and compare the ceria particles settlement data to the formulated ceria slurry. The ceria particles with larger size will settle faster than smaller size but particle concentration and additives in STI slurry has little impact on particle settlement dynamics. In the formulated ceria, the settlement of ceria particles can change the balance of abrasive to silicon oxide inhibitor ratio and has adversary effect on oxide polishing rates.

The properties of nano-silica colloid prepared by different processes in silicon wafer chemical mechanical polishing (CMP) were studied. The different principles of preparing nano-silica colloid by ion exchange, silica hydrolysis and hydrolytic of TEOS were analyzed respectively. The differences in structure, dispersion, density, and surface morphology were compared. Under the same CMP process parameters, silica colloids prepared by three different processes were used for polishing experiments. The results demonstrate that the hydrolysis of TEOS silica colloid is not suitable for CMP due to the network structure, which made the silica colloid as abrasive can not imply sufficient mechanical friction. The colloidal particles prepared by silica hydrolysis are denser, more uniform, with better dispersion and rough surface. The polishing rate of it is higher than that of ion exchange silica in a certain particle size range, and as the diameter increases, the growth increases.

In state of the art technologies, defect reduction is central to the achievement of low cost, high yield manufacturing. The defects occurred during the CMP process would lead to severe circuit failure and affect yield. In this paper, effect of slurry chemistry on surface defect during barrier CMP was studied. The experimental results showed that the complexation can effectively remove the copper residue, but would induce large dishing and erosion, if the complexation is so strong. The strong electrostatic attraction on oxide surface can improve the removal rate selectivity of OX to Cu and reduce the dishing and erosion. The dispersion effect and wetting effect can prevent the agglomeration of abrasive particles and make the copper surface hydrophilic, it can effectively reduce scratch defect during CMP.

The third-generation semiconductor material gallium nitride (GaN) has attracted more and more researchers attention due to its excellent performance. In the processing of GaN wafer, surface/subsurface damage would inevitably generate after diamond abrasive lapping. Chemical mechanical polishing (CMP) with soft abrasive is widely used to remove surface/subsurface damage and obtain the ultra-smooth wafer surface. However, traditional CMP of GaN wafer has very low material removal rate (MRR) because of the high hardness and chemical inertness of wafer. To improve GaN polishing MRR, hybrid-field effects polishing methods include photochemical mechanical polishing (PCMP) and photoelectrochemical mechanical polishing (PECMP) were proposed. Experimental results illustrated that both PCMP and PECMP methods could significantly improve MRR and surface quality. Meanwhile, the PCMP and PECMP mechanism were discussed.

The mechanical removal mechanism of silicon carbide crystal is investigated by Molecular Dynamics (MD) simulation in a fixed abrasive polishing. Special attention is paid to the effect of the sub-nano scratching depth on the mechanical removal behavior. It was found that only the amorphous phase transition occurs in SiC. The temperature, subsurface damage depth and removal rate of SiC substrates increase with the increase of scratching depth. Furthermore, the result shows that the scratching force increases as the scratching depth increases.

In order to expand the use of CMP technologies into new applications, it is necessary to develop polishing technologies for a diverse range of materials and shapes. To improve the material removal rate of chemically stable materials, it is important i) to increase the abrasive particle velocity (vs. polishing object) to maximize the friction, and ii) to increase the number of working (adhered/active) particles by controlling the surface charge. To polish 3D shape precisely, design of polishing consumables (3D pad, magnetic polish slurry, polishing compound) and accurate pressure control are the keys.

Biological growth on insulators is one of the reasons for unwanted insulator flashovers leading to MV network failures. Currently the contaminated insulators are being cleaned manually using a wet cloth as an abrasive or using a high-pressure washer attached to a bucket truck. This study aims to increase our understanding on the effectiveness of those cleaning methods. Holike and Buddhama 33kV feeders were selected for this study based on preliminary studies. First electrical tests were conducted on 20 contaminated insulators selected from these feeders. In parallel, samples of biological growth were removed from the insulators, cultured and identified. Finally, six insulators were cleaned using two commonly used methods and repeated key electrical tests. The study shows that manual cleaning of biologically contaminated insulators using a wet cloth or cotton waste is the best method which yield a 53% improvement in hydrophobicity, 24% improvement in wet flashover voltage and 15 times reduction in wet leakage current measurements.

In order to dispose of various explosives safely and efficiently, the paper studied the organic combination between pre-mixed abrasive jet cutting technology and robot technology. Through using this combination technology to complete the design and experiment of cutting various explosives, and the expected results had achieved. It showed that the cutting performance and parameters can be used for safe and efficient optimization design, which can provide technical support for subsequent research.

Owing to high hardness and brittleness, SiC single crystal is the typical difficult-to-machine material. The SiC single crystal workpiece was cut by wire saw excited by transverse ultrasonic, and the cutting process was analyzed in current research. The kinematics equation of ultrasonic excitation wire saw and ordinary wire saw were established, and two different kinematics characteristics were analyzed respectively. The trajectory of abrasive particles in two cutting mode changed fundamentally. The finite element simulation model of single diamond abrasive cutting SiC single crystal was established. The influence of processing parameters on sawing force, surface morphology of SiC single crystal cut with abrasive excited by ultrasonic and ordinary diamond abrasive cutting was analyzed. The results show that sawing force of diamond abrasive excited by ultrasonic is much less than that of ordinary diamond abrasive cutting and the surface morphology is fairly flat. The cutting depth of abrasive has a significant influence on the sawing force and wafer surface.

Surface damage is a common occurrence in mechanical equipment and directly affects the state of mechanical operation. In order to investigate the factors of surface wear of metal friction pairs, this paper studied the hemispherical abrasive grain model of friction surface wear. The ABAQUS finite element software was used to simulate the damage process of the surface material when the hemispherical abrasive particles were pressed at different cutting angles. And the equivalent plastic strain and Mises equivalent stress analysis were carried out. Simulations show that the change in surface damage is not only related to time, but also related to the extrusion surface of different cutting angles.

The paper presents a method for non-contact and non-invasive study and monitoring of cut-off wheel wear upon elastic abrasive cutting by applying the methods of infrared thermography and planned experiments. Theoretical and experimental models reflecting the dependence between cut-off wheel wear, cut-off wheel temperature and workpiece temperature have been built for different materials being machined (C45 and 42Cr4 steels). Temperature control possibilities are studied by choosing elastic abrasive cutting conditions so as to ensure the desired cut-off wheel wear values.

Chemical-mechanical polishing/planarization (CMP) is one of the key processes used in electronic chip manufacturing. In CMP, a rotating wafer is pressed facedown onto a rotating polishing pad. A chemical “slurry” containing abrasive particles and chemical reagents is deposited on the pad during polishing, and flows between the wafer and the pad. The combined action of the polishing pad, abrasive particles, and chemical reagents results in material removal and planarization of the wafer surface.In recent years, modeling of the CMP process has become critical for detection of planarity defects in chips before manufacturing. One of the key parameters affecting the surface planarization is the pressure, with which the wafer is pressed against the pad. Calculation of the pressure distribution across the wafer surface is crucial for modeling the CMP process. This pressure calculation typically uses contact mechanics methods that include solving an integral equation using fast Fourier (FFT) and inverse fast Fourier (IFFT) transforms. However, the kernel of the integral equation has singularities that lead to numerical instability.In this paper, we propose a method to avoid numerical instabilities in pressure calculation by using an analytical expression for the Fourier transform of the kernel function.

It is necessary to optimize the die structure for the low-pressure casting of aluminum alloy wheel hub which is prone to shrinkage cavity and porosity. This paper simulated the mold filling and solidification process when the change of the temperature field and stress field, based on the solidification mold defect factors in central composite experiment and response surface analysis to optimize method, finally complete the multi-objective optimization using the algorithm of the NSGA-I reasonably come to the abrasive wall thickness values. In terms of experimental verification, the phase structure of aluminum alloy casting was observed to be uniform and smooth without shrinkage cavity and porosity, which realized the lightweight design of the die and improved the quality of the die casting.

The main reasons for reducing the dynamic stability of the collector node during operation are caused by the lack of precision in the manufacture of individual elements. As a result of the analysis of technologies and methods for the treatment of surfaces with specified parameters, a jet-abrasive method was reasonably adopted, which allows texturing surfaces with high productivity.To optimize the processing modes using this method, a mathematical model has been developed for the interaction of abrasive particles with the surface of a copper lamella. The optimization criterion was the microrelief of the surface, the removal of the material appeared as a restriction. In addition, full-scale optimization was carried out for clearly not present technological parameters in a mathematical model, such as abrasive concentration and processing time.Experimental studies were carried out that confirmed the adequacy of the simulation and the correctness of the chosen technology. On this basis, an experimental batch of collector nodes was manufactured under production conditions. In this batch, the three nodes were made of textured copper lamellas, and three - control, according to factory technology.Manufacturing tests have shown that texturing surfaces with an increase in roughness without removing the material and without changing the geometric parameters of the profile allows in the zone of contact of copper lamellae with insulating plates to increase the coefficient of static friction, which leads to an increase in pressing force and, thus, obtain guaranteed tension and solidity collector site.

Shear thickening fluid polishing (STFP)is one type of the non-Newtonian fluids which is used to polish the complex shapes. This method is applied to machine the complex surfaces of mold in this study. The principle and performance of STFP was introduced. The parameters having significant influence on the STFP process, including polishing speed, abrasive concentration, abrasive sizes were experimentally investigated. In these parameters, the effect of inclination angle to the machining process is simulated in this paper. The inclination angle parameters of the workpieces such as 0°, 10°, 15°, 20°, and 25° are used during the simulation process. Cutting pressure area and polishing fluid flow characteristics will be presented and analyzed. When inclination angle parameters exceed 15°, the pressure area is distributed throughout all the surface of the surfaces. The maximum pressure can be reached about 7.95 kPa. Based on the simulation results to establish conditions for later experimental research.

The paper presents the results of tests topography and surface roughness of dies used in the cold forging proces. Were tested two tools withdrawn from work due to cracks and abrasive wear. In the analyses has been used Alicona InfiniteFocus G5, the device based on the method of the focus variation microscopy. The principle of its operation and the possibilities of its use to accurately determine the topography and surface roughness tests of forging tools have been described. On the basis of the conducted tests, it has been found that the impressions are subject to a typical abrasive wear mechanism, which affects the change of their dimensions and surface roughness.

A hybrid manufacturing process combining abrasive jet and laser micromaching enables the creation of living hinges in nitinol that retain the superelastic properties of the bulk material. The former selectively etches through the thickness of a workpiece and the latter defines the part’s final geometry. Because the majority of the material removal is done with the room-temperature mechanical etching procedure, thermal damage to the part is minimized. Processing parameters to achieve desired geometries are described, a bending stiffness model for the living hinges is provided, and validation experiments are presented. Lastly, to demonstrate the usefulness of these components to millimeter-sized robotic systems and medical devices, we show their integration in two prototype devices: an endoscopic camera wrist and a simple laser beam steering system.

A system that can calculate the abrasive corrosion and wall thinning of water-cooled wall tubes of boiler by measuring magnetic flux change was developed. A magnetizer, which is curved according to the cross-sectional shape of the tube, membrane and weld line, magnetizes a part of the water-cooled wall in the axial direction. At this time, the magnitude of the magnetic flux changes in a region where the thickness becomes thinner. This change in magnetic flux is measured by a magnetic sensor array deflected to one side from the center of the magnetizer.

In this research, a new type of slurry blast machine has been developed, which uses slurry mixtures of water and abrasives to impact moving steel belts to achieve mechanical descaling. A test rig of water pressure descaling system was established, and the descaling efficiency of slurry spray was tested. Then, the influence of motor speed, pressure, flow rate, and target distance on descaling efficiency was studied, and complete scale removal was realized. The experiment results exhibited: (1) the output impact force of the slurry blast machine is proportional to the motor speed and flow rate, and inversely proportional to the target distance. (2) The system pressure mainly affects the vacuum degree in the mixing chamber, and has little effect on the impact force. (3) Abrasive jet has a greater impact force than non-abrasive jet because the abrasive density increases the average density of mixed slurry jet. This research is expected to provide a guidance for the structural optimization of slurry blast machine, and it will also provide a new method used for strip descaling.

Cable accessories are the weakest parts in the whole cable system. The performance matching of the insulating materials on the interface is very important, and the same important is the smoothing of the insulation surfaces. The surface smoothness of the cable insulation depends on the peeling and smoothing techniques applied on site in a less well-controlled environment. The effect of surface smoothness of XLPE cable insulation on the electrical treeing characteristics at the XLPE-SIR interface was investigated in this paper. XLPE and SIR samples were pressed together under different interfacial pressures by a specific pressing device, with the surface of the XLPE sample roughed by using abrasive papers. AC voltages were applied on a set of pin-plane electrodes placed at the interface. The pin-plane distance was 2 mm. The needle diameter was 0.25 mm and the tip curvature radius was $(10\pm 1)\ \boldsymbol{\mu} \mathbf{m}$ . Under different interfacial pressures, the voltages for electrical trees to initiate were recorded and statistically analyzed for both smooth and rough XLPE surfaces. Meanwhile, the tree morphology and breakdown channel were also captured by using a digital microimaging system. It was shown that when the XLPE surface was smooth, electrical trees would initiate and grow along the interface at a low pressure, while they tended to grow into SIR side at a higher pressure. When the XLPE surface was rough, however, breakdown occurred directly at a low pressure; and at a higher pressure, electrical trees initiated and grew along the scratches on interface mostly. Besides, the electrical tree initiation voltages of the smooth surfaces were all higher than those of rough surfaces. It was indicated that a smooth insulating surface and an appropriate high interfacial pressure can effectively suppress the initiation of electrical trees.

Molecular dynamics simulations using Reactive Force Field (ReaxFF) are employed to study the silica glass chemical mechanical polishing (CMP) process in aqueous H2O2. The material removal mechanisms in CMP process are studied by analyzing the tribochemical process of silica glass. Results shows that the surface of silica glass is hydroxylated after the reaction with H2O2 solution. Through dehydrogenation and dehydroxylation, the Si-O-Si bridge bonds are formed between abrasive layer and silica glass surface. The chemical bonds between surface atoms and substrate atoms are broken due to the stretch of bridge bonds. The relationship between the sliding speed and the removal of atoms is also studied.

The effect of particle size factors of nano-silica colloidal abrasives on chemical mechanical polishing (CMP) of sapphire wafers was studied. Under the same CMP condition, uniform monodisperse particle size abrasives and mixed particle size abrasives were prepared for polishing experiments, and the dispersion of the abrasive particle size and the surface roughness of the polished wafer were obtained by transmission electron micrograph (TEM) and atomic force microscope (AFM), respectively. The results demonstrate that the abrasive with mixed particle size has better effect on the material removal rate (MRR) than the abrasive with uniform particle size, which is up to 7.22 μm/h, and the effect of abrasive particle size on CMP performance is revealed.

In recent time published research indicates only limited works have been addressed in the field of machining properties with respect to ecofriendly materials. However, characteristic natural fibers have extraordinary potential for decreasing the materials weight, bio-degradable, and bringing down material cost. The aim of the present work is to focus mainly on the abrasive waterjet machining of Kevlar composite and hybridized Kevlar-Jute fiber Reinforced Epoxy Composite. An endeavor is made to minimize the use of manufactured synthetic Kevlar fiber by incorporating natural jute strands to such an extent that the resultant hybrid composite shows superior quality when compared with single fortifications of jute strands. Composite laminates are synthesized using hand lay-up technique. The test specimen were synthesized and characterization has been performed according to the American Society for Testing and Materials (ASTM) standards. The composites were synthesized using Epoxy Resin (Razeen® LR 1150) and Hardener (ADDcure® 91618) along with reinforcing fiber Jute & Kevlar. Finally, the design of experiments is conducted using Taguchi Approach, wear testing using Taber Abrader Model 5135 for checking the wear formation in the material for different number of cycles, statistical models are analyzed using Analysis of variance (ANOVA), and microscopic investigation is carried out to examine the internal structure of ruptured surfaces and its failure morphology using scanning electron microscopy (SEM).

In this study, the impact of diamond coating on the micro-milling of aluminum 7050 alloy was investigated experimentally. For different cutting parameters, cutting forces, surface roughness and change in the size of the burrs are obtained. In the experiments, 0.5 mm diameter nano-crystalline diamond (NCD) coated and uncoated tungsten carbide tools were used. According to the results obtained, the NCD coating causes the cutting forces to decrease. The critical feed rate value is estimated for the surface roughness that is approximately 0.5 times the radius of the cutting edge. The Ra value increases at smaller feed values than the critical feed value. NCD coating did not affect the burrs positively / negatively. Abrasive wear and BUE were observed on micro tools. NCD coating causes abrasive wear on the tool to decrease and tool life to increase.