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X-ray spectroscopic microanalysis was used to determine the concentration of titanium on the surface of the wear spot of a silicon carbide crystal during micro-scratching and the concentration of silicon on the treated surface after grinding by a wheel of silicon carbide. The wear resistance and grinding coefficient of titanium alloys under micro-scratching with single crystals and grinding with wheels made of corundum, silicon carbide, cubic boron nitride and diamond were determined. The morphology of the treated surface and the regularities of changes in the indicators of the grinding process of titanium alloys with circles of various characteristics were studied. The features of the process of grinding titanium alloys using various lubricants and coolants are shown. The influence of the characteristics of the abrasive tool and grinding modes on low-cycle fatigue on the operation of flat and round grinding of samples made of titanium alloys VT9 and VT22 was studied. The influence of abrasive material, grinding speed, feed and sparkout during finishing on low-cycle fatigue was analyzed. Based on the research, recommendations were given for choosing a rational characteristic of the abrasive tool and processing modes.

The article deals with the construction of an intensive process of grinding materials using a precast textured wheel and a device for the centrifugal giving of lubricating and cooling liquid (LCL) directly to the local contact zones of the cutting and pressing abrasive grains with the processed material. The design of the tool and an effective method of coolant giving to the cutting zone are described, which provide the required roughness of the treated surface and eliminate structural changes in the surface layer under intensive grinding conditions. An increase in the rate of heat removal from the grinding zone is achieved by using a textured tool design, a device for centrifugal giving of coolant and accelerating the liquid to approximately the cutting speed. A method for constructing an intensive grinding process with a precast textured tool has been developed, the implementation of which can significantly increase the processing efficiency. The results of the research are recommended for grinding steels, cast iron and other metals and alloys that are prone to the formation of cauterization, tensile residual stresses and other thermal defects that occur under the influence of high temperature in the grinding zone.

Based on the current processing technology of large-scale spherical roller bearing rings, the dimensional expansion and contraction and the geometric variation of large-scale spherical roller bearing rings before and after heat treatment have been studied through several groups of processing experiment and data analysis. Optimization design of grinding allowance of large-scale spherical roller bearing rings have been implemented by using calculation formula of grinding allowance in bearing industry, which improved the production efficiency of the large spherical roller bearing rings and saved the manufacturing cost.

This study presents a prediction study of the surface hardness in surface grinding ASIS 1045 steel. Base on the experimental data on the changes in characteristics of steel in the heat treatment processes, the relationship between the surface hardness and the impacted temperature in surface was found. Besides, the relationship between the cutting temperature and the technology parameters in the grinding was created. The surface hardness was then formulated as a function of the technology parameters in the grinding processes such as the depth of cut, the grinding wheel speed, the workpiece speed, etc. The proposed model was verified by comparing the predicted and measured results of surface hardness. This model can be used to predict the surface hardness when surface grinding.

The objective of this paper is to clarify the effect of grinding surface characteristics in the grinding of a titanium alloy with a coolant supply from the inner side of the grinding wheel. In this paper, we selected a white aluminum oxide (WA) vitrified bonded grinding wheel and a green silicon carbide (GC) vitrified bonded grinding wheel, and compared their grinding characteristics. As a result, in the case of the GC vitrified bonded grinding wheel, the surface roughness decreased by about 54% and the compressive residual stress increased by about 128%.

The objective of this paper is to clarify the effect of the difference of grinding fluid supply method on grinding surface characteristics during the curved surface machining of titanium alloy. The convex and concave type workpieces were machined by internal coolant supply and external coolant supply, and the surface characteristics were compared. The internal coolant supply could supply the grinding fluid directly to the machining point through the grinding wheel pores. One nozzle or seven nozzles were used for external coolant supply. As a result, the surface roughness of the concave surface decreased by about 10 % compared with the one nozzle was used when the grinding fluid was supplied from the inner side of the grinding wheel. In the case of the convex surface, the surface roughness decreased about 20 % compared with the single nozzle was used, and it decreased about 9 % compared with the seven nozzles were used.

Based on orthogonal experiments, the influences of grinding process parameters including depth of cut (ap), workpiece infeed velocity (vw) and transverse regrinding value (Cr) on hardened layer depth (HLD) of 40Cr steel are studied in the grind-hardening process. The grind-hardening orthogonal experiments of 3-factors are performed on the 40Cr steel with the L16 (45) orthogonal table and the experimental optimization design theory. To understand quantitatively the effects of three grinding process parameters, the experimental data are modeled by regression. Among three grinding process parameters, the most important parameter is ap, followed by vw and Cr respectively. The experimental results indicate that HLD would increase with the increasing of the depth of cut and the decreasing of the workpiece infeed velocity in grind-hardening process, but HLD would decrease with the increasing of the interaction between the depth of cut and workpiece infeed velocity.

Fast development of nanotechnology leads to the top-down preparation of nanoparticles by various disintegration techniques taking a major part in the industrial sector. A very promising way seems to be the use of cavitation implosions. In our approach, the main mechanism of this type of disintegration is based on mutual collisions of solid microparticles in dense dispersions, powered by implosions of vapour cavitation bubbles generated between the particles.This paper presents experimental results of the disintegration of silicon microparticles to the sub-micron scale. In our experiments, the primary silicon particles of mean size of 5927 nm were reduced to 160 nm and 736 nm by the ultrasonic disintegration process after 240 minutes and at the ultrasonic frequency of 32 kHz. We also present a phenomenological model of particles erosive disintegration where particle fragments are approximated by spheres of equivalent volume. This model allows us to calculate the energy needed for successful disintegration of primary microparticles by measuring the particle size distribution. Thus, we can estimate the minimal energy conserved in the cavitation bubble alongside with its radius at a normal pressure of the surrounding liquid.

CMCs have been developed in the 80th for the shuttle programs and commercialized as brake discs from 2000 till today. Since 2017 CMCs are used also in components of flight gas turbines. This application requires highest levels of process and material development and performance. Therefore the knowledge of any process on material damage is of highest importance.The presented work will show a method how to evaluate the quality of edges and surfaces of CMCs created by a special diamond machining operation. The objective is to develop a machining process for CMCs in gas turbine applications and a method for quality assessment for future production.

This paper evaluates the effect of grinding dust (GD), a waste generated in the clutch disc finishing process, on Portland cement hydration. For this, pastes with additions of 5%, 10% and 15% GD, relative to cement weight, were molded and compared with a reference sample. Tests of setting time determination by Vicat needle, calorimetry, monitoring the ultrasonic pulse propagation velocity and mineralogical analysis (X-ray diffraction) in pastes with 1 day of hydration were carried out. It was observed that GD, due to the presence of copper, zinc and phenolic resin in its composition, is responsible for retarding cement hydration and thus increases the setting time and delays the evolution of heat release and pulse propagation velocity. However, the formation of new crystalline phases was not observed.

This paper presents a study on determining optimum parameters for lubrication in external grinding process. In the study, experiments were designed by using Taguchi technique. The experiments were set up with Oemeta Unimet AS 192 lubricant, Al2O3 grinding wheel and the workpiece material of tool steel 9CrSi. From the results of the experiments, the influences of coolant parameters on the surface roughness were analyzed. It was found that the concentration of lubricant was the most impact, the second is flow rate and the coolant pressure has little impact on the surface roughness. Also, the optimum parameters of lubrication for getting minimum surface roughness were proposed.

Worm gear set is composed by the worm and worm wheel. It is an important transmission device for crossed axes transmission with high gear ratio. Worm gears can be produced in several ways, depending on the size of the transmission, the number of threads, the type of the worm and the purpose of application, etc. The contact is highly related to the precision of tooth profile. The best way to control the characteristic of contact is done by the modified worm profile. This paper deals with the manufacture of ZI-Worm whose theoretical tooth surface is generated by a screw motion of a straight line. In order to manufacture the worm with modified high precision tooth profile, the most important consideration is how to develop the profile of the grinding wheel in the worm grinding process. It is the essential requirement for the development of grinding machine for the worm. This article therefore deals with the problems of how to generate the profile of the grinding wheel. By the development of the grinding machine, we can complete the worm surface and tools for the production.

Cutting tools made of polycrystalline diamond (PCD) are used for machining of aluminum alloys, fiber-reinforced plastic composites and wood. Compared to cemented carbide tools with geometrically defined cutting edges, PCD tools offer significant advantages with respect to tool life. High demands regarding the cutting edge roughness and the quality of the rake and the flank face usually require a grinding process with diamond grinding wheels. The PCD grinding process, however, is characterized by low material removal rates and high grinding wheel wear. The material removal rate and the grinding wheel wear, in turn, highly depend on the process state variables process force and process temperature. However, the relationship between these process state variables and the process input variables is largely unknown. This work provides a contribution to the closure of this knowledge gap by means of an adapted friction law. A single grain friction test stand using the pin-disk principle was developed, which enables a measurement of the friction force and the contact zone temperature for normal forces and relative speeds that are common in PCD grinding. During the experiments, the specification of the PCD disc, the cross-sectional area of the friction sample made of monocrystalline diamond as well as the process parameters normal force and relative speed were varied. In addition, the tests were carried out without lubrication as well as with a minimum lubrication. A high correlation between the contact force and the coefficient of friction was determined. This relationship was mathematically formulated in a friction law. In addition, a direct influence of the contact force and the relative velocity on the contact zone temperature was identified. The knowledge gained leads to an improved understanding of the PCD grinding process and thus enables a more efficient grinding process design.

In this paper, based on micro wear form, an approach that using protrusion height, average tool angle, blunt area ratio and coated density to describe the wear of abrasive belt is put forward. The method for calculating the above parameters are also introduced. In experiments, we use the profilometer to collect the abrasive belt surface data and draw figures of the above parameters under service time, which indicates that using topography parameters can describe the degree of belt wear. According to parameters changing slope, the abrasive belt service time is roughly divided into two stages, initial wear stage and stable wear stage but no abrupt wear stage. Initial worn stage grains suffer more stress, patterns of wear are mainly severe wear and pull-off, while stable wear stage grains bear less stress and pattern of worn is dominated by mild wear. In addition to that, the other parameters changing trend is agreed and synchronous with protrusion height.

In the hole drilling process, produced chip cannot be released from the inside hole which leads to broken glass plate due to the adhered chip on tool. Chip discharge method was announced by many researchers. However, the method using the tool-only with drilling command is rarely seen. In this laboratory, we have developed a tool in order to discharge chip. The developed tool is capable in preventing chip adhesion and producing high quality and efficient hole drilling process. The developed tool has several hundred times longer tool life than a conventional tool. However, the amount of adhered chips on cutting tool increase as the number of hole drilling process increases. The chip adhesion condition is different according to the kind of grinding fluid. Adhesion of chips on tool can be related to the properties of grinding fluid. Thus, in this study, the types of grinding fluid used during the hole drilling process were investigated to determine the state of chip adhesion. Three types of grinding fluid used are Emulsion, Soluble and Solution and all of them include surfactant which is considered to have an effect on prevention of chip adhesion. The main conclusions obtained in this study are as follows. Chip adhesion state was investigated after drilling process and it was found that instead of grinding fluid properties, surfactant also has significant effect on chip adhesion on tool by absorbing the adhered chip from the tool. The results showed that grinding fluid with long-chain surfactant has small amount of chip adhesion whereas grinding fluid with short-chain surfactant has large amount of chip adhesion. Therefore, it can be concluded that grinding fluid with long-chain surfactant is capable in preventing chip adhesion during hole drilling process.

Thermally sprayed tungsten carbide-based coatings deposited by High Velocity Oxygen Fuel (HVOF) has been widely developed for its high corrosion and wear resistance. The finishing of the coated surface by grinding process is essential because of the high surface roughness of carbide coatings. Residual stresses existing in most hard coatings have significant influence on the adhesion, mechanical properties and tribological performance. The present study investigated the effect of grinding process on the residual stress of WC-10Co-4Cr coating by HVOF. The residual stress of coating was measured by the X-ray diffraction (XRD) technique using sin2ψ method. In addition, the effect of diffraction peak positioning method on the accuracy of residual stress of WC-10Co-4Cr coating was determined in the XRD technique. Four peak positioning methods and their effects on the accuracy of X-ray diffraction (XRD) residual stress measurement are considered. The results showed that the compressive residual stress of the WC-10Co-4Cr coating increase after grinding process. The parabolic method was selected for the peak positioning to measure the precise residual stress of HVOF-deposited WC-10Co-4Cr coating.

The paper presents results of the investigation into efficiency of high-tensile composite materials grinding with metal bonded diamond abrasive tools, as well as it demonstrates the necessity to stabilize diamond disks cutting properties in order to reduce cutting power, since it is one of important economic indicators of processing. The comparative analysis of preliminary studies of various diamond processing methods reveals that the minimal cutting power is observed when using the combined method of electric powered diamond processing which includes electrochemical grinding and simultaneous continuous electrochemical dressing of the grinding disk surface. Further research into the suggested method reveals relevant mathematical dependences of metal-bonded diamond disks cutting power and electric modes. The analysis of the results shows that combining of hard-alloy surface electrochemical dissolution and electrochemical dressing of the disk surface facilitates mechanical cutting with high effectiveness and little effort. This leads to substantial reduction of cutting power as compared with other methods. The reasonable electric modes are discovered which provide the minimal cutting power without reducing efficiency of the process and quality of finished product.

The article provides an overview of manufacturing a binding agent via combined grinding a silicate lump and calcium chloride. The data on the mineralogical composition of a mechanically activated binding agent are presented. The paper also describes composition and properties of putty on the base of a modified binding agent, which is intended for interior finishing operations in buildings.

We propose the technique of guaranteed quality wear resistant plasma coatings of high-chromium powder material. The appropriate system of engineering models had to be designed in order to obtain the summarized results, as well as to manage the parameters of quality indicators at all stages of the technological processing procedure. Thus, surface roughness was accepted as a criterion in the model development at the stage of preliminary mechanical processing before spraying coatings. The model of plasma coating process proper takes into account the influence of spraying on the main quality indicators, such as adhesive strength, porosity, and the level of residual stresses. The engineering model of finish abrasive grinding is based on ensuring the desired value of the surface roughness parameter provided the geometric and dimensional accuracy of details was achieved.

The paper deals with the influence of level of grinding of the recycled concrete. Level of grinding mostly influence the hydration heat evolution of cement paste. Measurement of hydration heat evolution is one of the ways to detect reactive properties of recycled concrete powder modified by high speed mill device. Basic characteristics that most influence the hydraulic properties of recycled concrete powder are grin size diagram and chemical composition of the original concrete. Non-hydrated inner part of cement grains could further react if it is exposed to water. In this experiment the recycled concrete from recycled railroad sleepers and structural layers of the D2 highway was used. Recycled concrete powder from highway was divided into 4 more variants which differ by grinding process during production. To detect difference in hydration process four mixtures of cement paste with different types of recycled concrete powder were made and further subjected to calorimetric measurement. The results were after compared with the hydration heat rate of reference cement paste. According to results the type of milling process had minor influence on hydraulic properties of recycled concrete powder compared with influence of origin of recycled concrete.

The article deals with the shrinkage of a cement composite with various contents of waste micronized limestone powder with a fraction size of 0-63 μm and crushed limestone with a fraction size of 0-2 mm. Waste micronized powder is produced by high-speed grinding of marble sludge. The difference in shrinkage of various mixtures has been described by means of structural analysis. Electron microscopy has been used for this analysis. Mixtures with 10 wt. % of cement and various ratios of micronized marble powder to crushed limestone (1: 1; 1: 2; 2: 1; 1: 0) were investigated. The increasing amount of waste micronized powder adversely affects the shrinkage of the cement composite. This effect is caused by the increasing water–cement ratio for the purpose of achieving the same workability of the mixture.

In this research, the effects of main parameters such as speed of agitator, concentration and redium change ratio on the grinding effect were studied by the method of wet-grinding. The powder was characterized and analyzed by means of particle size analysis and scanning electron microscope. The results show that the mechanical grinding method can effectively prepare micro-nanosilicon carbide powder with particle size of about 130nm, the optimum parameter is the rotational speed 1000r/min, the concentration is 30%, the medium change ratio is 75%.

The formation mechanism of α-Fe2O3 on iron-bonded diamond wheel surface by ELID grinding is presented here. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques were used to analyze the compositions of the oxide films. X-ray diffraction analysis demonstrated the existence of the diffraction peak of α-Fe2O3, which was observed in ELID grinding iron-bonded diamond wheel surface. To illustrate the correctness of our theory, X-ray photoelectron spectroscopy analysis was also performed. Results reveal that the characteristic spectrum of oxide film on ELID wheel has coincidence with the standard spectrum of Fe2p in α-Fe2O3. These results suggest the existence of α-Fe2O3 in oxide films on the grinding wheel surface. The potentiality that α-Fe2O3 can bring polishing effect to ELID grinding process has also been discussed. It helps understand how ELID grinding can achieve excellent surface finish for the workpiece.

Mineral additives are materials which are used in wide range of industries including construction, cosmetics, agricultural and biotechnology. Such materials as plasters, paints, abrasives etc. are produced using mineral powders. Main qualities of mineral additives are purity of chemical composition, grading properties and shape factor. To obtain powder like material most common method is milling. One of most effective milling method for refining of brittle material is grinding by collision in disintegrator. One of advantage of this method is that high milling energy is transferred to the milling material in short period of time. In present research three types of mineral materials were treated in disintegrator with specific energy Es applied 8.4 and 25.2 kWh/t: natural quartz sand 0.3/1mm, quartz-limestone 0.3/2.5mm sand and dolomite screenings 0/4mm. Results indicate that powder like material with d90 form 66 to 141 µm could be obtained at Es 8.4 kWh/t while increase of Es reduces d90 value to 48 to 72 µm and the milling efficiency was effected by the sand type.

Fibrous composite materials with metal matrices are effectively employed in the newest technical fields. Researches related to the development of composite materials, containing W-B fibers are among them. Fibrous composite materials are effectively used in newest technical industries because of their high durability, small weight and other valuable properties. The paper describes the features of grinding Al-W-B waste using a disintegrator to obtain W-B fiber powder with a specified particle size. A number of mixtures with the metal substrate are offered. Methods for preparing samples of various compositions containing W-B fibers are observed. Results of research of physical-mechanical, tribological properties and microstructure of materials are brought.

This article presents the results of fly ash from Circulating fluidized Bed Combustion (CFBC) and high temperature fly ash (defined in EN 450-1) with modified physical parameters by grinding. For this treatment was used the mechanical mill. In this case were used two fly ashes. The first sample was from Tisová power plant (CFBC fly ash) and the second one from Počerady power plant (high temperature fly ash). The modified samples were tested for the effect of grinding time on its grindability and granulometry. For testing of samples was used laser diffraction with particle size analyzer and the grindability was determined. The reason for this step was found more stable and better material which achieves better physical and mechanical properties. The first step is mechanical treatment of fly ash’s granule.

The influence of grinding silica-containing raw materials in various mills on the reactivity of fillers at their contact with cement has been researched. The analysis of the research has shown that as a result of mechanical treatment of the feedstock a significant increase in its activity can be achieved. Thus, the greatest effect can be obtained by the use of mechanically activated filler of quartz sandstone and wet magnetic separation waste, ground in a planetary ball mill. It has been proved that this is due to the formation of Bronsted acid sites on the surface of fillers, which are capable of forming strong hydrogen bonds with the cement hydration products and of participating in ion exchange reactions intergranular contact formation. There is a pronounced dependence between the increase in the strength characteristics of the samples of system "mineral filler - cement" and increase of concentration of active sites on the surface of the mineral materials.

The grinding hardening workpiece deformation caused by high temperature leads to the variation of the grinding force. Grinding force of dynamic variation affects the grinding depth of hardened layer distribution. So it is necessary to study the variation rule of grinding hardening force. Through grinding arc temperature analysis and deformation analysis, the influence factor for grinding arc temperature and workpiece deformation on grinding force is analyzed. The analysis results are compared with the experimental results.

In the automotive industry, grinding of round diameters is an important process, to achieve desired tolerances and finish. While the effect of grinding parameters namely cutting velocity, work velocity and infeed (or downfeed) on grinding forces and surface integrity (that includes finish, residual stresses and subsurface damage) have been studied extensively in the literature, the effect on material removal rate (MRR) and dimensional accuracies has been given very limited attention. This work involves the analysis of effect of grinding parameters namely cutting velocity, work speed and infeed on MRR, surface finish (Ra) and dimensional accuracies by performing experiments on micro-alloyed steel bars. A series of cylindrical plunge grinding experiments were performed on round bar using CBN grinding wheel. The results show that, to achieve minimum surface roughness (Ra), infeed is the most influencing input parameter, whereas to achieve maximum MRR, work speed influences the most. An increase in infeed and a reduction in cutting velocity and work speed, leads to an increase in finish on ground surface. Also, an increase in infeed and cutting velocity, and a reduction in work speed results into an increase in MRR. The results show that, dimensional accuracies such as diameter, ovality and taper of ground surfaces have not been affected significantly.

In this work, novel Cu/BiVO4 photocatalyst were prepared by a low-temperature solid state grinding method using Bi (NO3)3•5H2O, NH4VO3 and Cu (NO3)2•2H2O as raw materials. The structure and properties of the samples were characterized by Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and UV-vis diffused reflectance spectroscopy (DRS); Using the degradation of methyl orange (MO) as the probe, it was simulated as the degradation of sewage under the visible light to study the influence of the illumination time and the amount of photocatalysts. Compared with the pure BiVO4, the visible-light absorption scope of BiVO4 was broadened by doping Cu, the UV-Visible absorption edges were slightly red shift and the band gap was narrower. Comparatively speaking, the results indicted that the doped Cu enhanced the photocatalytic activities of BiVO4.

Rolls are important tools in the steel industry. With the increase of the automobile and the mould, rolls are increasing rapidly. Hard rolls are very difficult to cut, almost all hard rolls are cut by only by grinding, and the grinding efficiency is relatively low, and it consumes a lot of cutting fluid. In this paper, the life and tool wear of ceramic tools in different cutting conditions were analyzed. Crack, chipping of cutting tools were analyzed. The experimental and theoretical analysis confirmed that the generation and expansion of the crack are the main wear mechanism of the tool failure, when the ceramic tools cutting cold rolls.

This study reports the results of investigation on the main and interaction effects of grit type, aging temperature, and aging time on particle size of ground natural rubber/zeolite (GNR/Z) composite powder using general factorial design of experiment. GNR/Z composite powder produced by mechanical grinding is porous, like an aggregated chain structure. These aggregates exist in clusters of irregular shape. Analysis of variance (ANOVA) shows that the effects of aging temperature and aging time depend on the particle size range. GNR/Z composite powder with large particle size is produced when aging is done at low temperature and short time due to high resistance of rubber to oxidation. On the other hand, GNR/Z composite powder with small particle size is produced when aging is done at low or high temperature and longer aging time. Low temperature condition offers high O2 concentration available to oxidize rubber while high temperature condition leads to more chain scissions due to higher oxidation rate.

A novel principle of cup wheel grinding of rotating concave quadric surface was proposed. The mathematical model of machining process was established to prove the feasibility of precision grinding of rotating concave paraboloid based on the introduced principle. The conditions of non-interference grinding of concave paraboloid were mathematically derived. The processing range and its influence factors were discussed. The trajectory equation of abrasive particle was concluded. Finally, the math expressions of numerical controlled parameters was put forward in the process of grinding of the concave paraboloid.

Single abrasive-grain cutting is the key research point in grinding process. Because of the narrow space and quick velocity, modeling and simulation method is an approach way to study the single grain cutting. This paper studied the distribution of flow stress and plastic strain, the temperature field near cutting grain. Then experiment was conducted to measure the cutting forces in single grain cutting test. The validation shows good correctness and accuracy of FEA model. Then orthogonal simulation test was carried out to research the influence factors for the grinding forces and temperature distribution. It is found that creep feed grinding has a large grinding forces than high speed grinding in the grain scales. But the maximum temperature value is affected both by depth and speed distinctly.

High-speed grinding experiment of titanium matrix composites is carried out with cubic boron nitride (CBN) superabrasive wheels in this work. The heat transfer into the titanium matrix composites (TMCs) is discussed based on theoretical analysis. A calculation method of thermal ratio passing into the workpiece is represented. Results obtained show that high-speed grinding of PTMCs using vitrified CBN wheel has a greater thermal ratio passing into the workpiece than using electroplated CBN wheel. Moreover, a linear relationship is established between es and ds1/4ap-3/4vw-1/2.

Through the dynamic and static analysis of SMF6020 precision grinder bed, the maximum deformation is obtained in the machining process of the bed, and the natural frequency and vibration mode. It provides a theoretical basis for improving the design of the whole structure of precision grinding machine.

High hardness surface coating sphere components are widely used in metal sealing ball valves. The spherical surface grinding texture influences the valve’s tribological performances such as friction, lubrication and wear of interacting surfaces. It can be used to develop the index of grinding parameter optimization. In this paper, based on the discussion of sphere generating grinding methods, the surface grinding texture is quantitatively analyzed. The space trajectory of abrasive particles during sphere grinding is studied. The trajectory mathematical models are built based on two kinds of sphere grinding manners and are verified by comparing the theoretical results against experimental measurements. The influence of grinding parameters on the texture is analyzed. Texture density are defined to quantitatively describe the surface texture. The relationship between grinding texture and ball valve performance is finally discussed. The conclusions can help to optimize the spherical surface grinding process.

To avoid the influence of column vibration on machining precision, it is necessary to simulate the stiffness characteristics of the columns for CNC grinding machine, and to optimize the structure of the column by using sensitivity method. Based on structural characteristics of the grinding machine and structural characteristics of the columns, a finite element model is established to simulate and calculate the first-four models of the columns. In order to optimize the structure of the column, a sensitivity analysis is made to calculate the sensitivity of natural frequencies and mass of the column to each panel and ribbed plate. Considering a weighting factor and taking integrated natural frequency of the column as an optimization objective, the mass of the column as a constraint, an optimization equation is established. By a quadratic programming method, the parameter optimization of the column is got as follows: the mass decreased by 4%, integrated natural frequency increased by 2%. Dynamic stiffness of the column has been optimized by harmonic response analysis, the results showed that the largest column in the Z resonance peak reduced by 8.44%.

The heavy belt-grinding is a new machining method, which combined the characters of heavy-duty grinding and belt-grinding together, with high efficiency and low cost. In the present paper the removal rate model of heavy belt-grinding in manufacturing of U71Mn steel is established. It is assumed that the distribution of the abrasive particles protrusion height of the abrasive belt surface closes to Gaussian distribution. The model is presented by calculating the removal volumes of all abrasive grains contributing to cutting action based on the probability theory, elastic-plastic mechanics and abrasive cutting theory. It is analysis that the material removal rate depends essentially on the mechanical properties of the workpiece and the belt and the grinding conditions. It is proportional to the average pressure, belt velocity and the indentation depth and is inverse proportion to the grain size.

To avoid the influence of column vibration on machining precision, it is necessary to simulate the stiffness characteristics of the columns for CNC grinding machine, and to optimize the structure of the column by using sensitivity method. Based on structural characteristics of the grinding machine and structural characteristics of the columns, a finite element model is established to simulate and calculate the first-four models of the columns. In order to optimize the structure of the column, a sensitivity analysis is made to calculate the sensitivity of natural frequencies and mass of the column to each panel and ribbed plate. Considering a weighting factor and taking integrated natural frequency of the column as an optimization objective, the mass of the column as a constraint, an optimization equation is established. By a quadratic programming method, the parameter optimization of the column is got as follows: the mass decreased by 4%, integrated natural frequency increased by 2%. Dynamic stiffness of the column has been optimized by harmonic response analysis, the results showed that the largest column in the Z resonance peak reduced by 8.44%.

Deepwater pipeline repairing machine (DPRM) is an appropriative equipment which is used to repair damaged deepwater oil and gas pipelines. With the development of deepwater oil and gas exploitation, inventions of such kinds of equipments are urgent priorities. Grinding technology is used in DPRM to remove pipeline anticorrosive coating. It is easy to cut the pipeline excessively when grinding pipeline anticorrosive coating for large orality of deepwater pipelines, which is not conducive to use mechanical connector to seal the pipeline. In order to settle this problem, the rotating compliant mechanism is designed and the grinding tool is steel wire brush. Based on the theory of boundary layer, the underwater rotating mechanical model of grinding tools is established to gain the relationship between grinding drag torque and grinding tool radius, rotational speed, and positive pressure. The grinding experiment gives the effect of structural parameters of steel wire brush on removing anticorrosive coating and indicates that medium density bowl type steel wire brush is the best choice. Finally, the grinding pipeline anticorrosive coating test is completed to verify the rationality of the design of grinding device. These studies provide technical basis for the development of deepwater multifunctional pipeline repair machinery.

Dental ceramics has become dominant materials used in dental restorations. Dental ceramics have several advantages, such as stable performance, good bio-compatibility, little possibility to attach plaque, and similarity to the color of permanent tooth. However complex surface characteristics and hard and brittle properties of dental ceramic materials caused difficulties in the processing and subsequent grinding. The complicated craft and high failure rate of dental ceramics greatly limit its wide application in clinical. Thus, fully understanding the special cutting tools grinding performance and researching the material damage process caused by grinding temperature and grinding force are of great significance. Research on dental ceramic grinding was reviewed in this paper. The removal mechanism of dental ceramic materials and the influence of parameters settings on the grinding force, grinding temperature, and the surface quality have been studied. Besides the existing problems in dental ceramic grinding technology were pointed out.

CAD/CAM technology has been widely applied in the field of oral restoration, which creates a revolutionary change in the pattern of traditional handmade denture and puts forward new demands on the past medical dental restorative material. The materials used for making dentures should own good machining properties and biocompatibilities. Medical zirconium ceramic have a broad prospect in the field of oral restoration because of its features are high strength, high toughness, good biocompatibility, high similarity of performance and aesthetic effect of processed dentures to real dentals. Dental restoration was obtained initially by NC machining using the feature that zirconium ceramic was not fully hardened but had a definite range of strength in the semi-sintered state. Experimental results shown that the ceramic denture machined by this processing has better surface quality and can satisfy requirements of oral restoration. Observation results shown that cutting surfaces were smooth, grinding cracks were tiny and uniform, and there were no obvious fracture gaps on edges and complex irregular surface of neck could be better reflected.

In cam grinding process, the grinding force changes with the change of cam contour, and its change leads to create the error of X-C linkage servo-tracking position, all of the factors reduce the cam the contour accuracy. To improve the accuracy of the cam profile, and research the effect of X-C axis servo tracking, the key vector of grinding force to the position is proposed, in which the factors have been considered including the grinding depth, curvature change, cam width, length and other effects. According to the mechanical analysis of cam and grinding wheel, a cam grinding XC-axis grinding force model is established. With the flat-bottomed follower cam as an example, the grinding force of X axis and C axis is calculated. The cam grinding experiment was conducted in the grinding machine, the tangential grinding force and normal grinding force were obtained and the model was verified. The grinding force mathematical model of X-C linkage provides the theoretical basis for the servo tracking position of X-C linkage grinding.

The paper presents results of influence of modified artificial plasma on corrosion resistance of Ti6Al4V ELI alloy. The samples were subjected to grinding, anodic oxidation and steam sterilization. After 28-day exposure to Ringer’s solution as well as Tas - SBF and R - SBF fluids, studies of electrochemical impedance spectroscopy, corrosion resistance and the amount of metal ions released into the solutions were carried out. The obtained results were compared to the results obtained for the samples in the initial state. It was found that the highest reactivity in contact with the Ti6Al4V ELI alloy was observed for the Tas - SBF containing TRIS whereas the lowest reactivity was observed for the Ringer's solution. The obtained results indicate the possible use of the modified physiological solutions, in order to carry out a more rigorous test of corrosion resistance of metal materials.

The selection of optimum machining parameters plays a significant role for the quality characteristics of products and its costs for grinding. This study describes the optimization of the grinding process for an optimal parametric combination to yield a surface roughness using the Taguchi method. An orthogonal array and analysis of variance are employed to investigate the effects of cutting environment (A), depth of cut (B) and feed rate (C) on the surface roughness characteristics of mold steels. Confirmation experiments were conducted to verify the optimal testing parameters. The experimental results indicated that the surface finish decreased with cutting-fluid and depth of cut, but decreased with increasing feed rate. It is revealed that the cutting fluid environment had highest physical as well as statistical influence on the surface roughness (71.38%), followed by depth of cut (25.54%), but the least effect was exhibited by feed rate (1.62%).

This paper indicates the occurrence of high thermal energy in the surface layer of workpiece material during the process of grinding. To help identify the share of heat which affects the workpiece, firstly the analysis of past research in the field of heat transfer during grinding was conducted. Further there is a proposition of analytical expression for heat distribution factor to the workpiece in the grinding process. Goal of this analytical dependence is to achieve more efficient production of mechanical parts without thermal defects in the surface layer of the part. Presented equation for energy partition has a characteristic of widespread practical use.

In the most cases manufacturing of injection mold and its cavities comprise more than half of the total production time. Very fine finishing operations can increase production time and cost of injection mold. Appropriate choice of finishing operations and injection technological parameters can reduce price of injection mold production, shorten production time and thus lower price of small and thin injection molded parts. Tool material X38CrMoV5-1, used for cavity in injection mold, was finished by fine turning, grinding, lapping and polishing with different technological conditions to achieve various surface roughness. The main aim of this research is to find an influence of surface quality of cavity and injection technological parameters on the surface quality of injection molded parts.

This work describes methods of designing grinding cycles and controlling them. We demonstrate that using modern equipment allows programming stepless feed change during whole finishing cycle, giving opportunity to organize more complex high productive cycles of abrasive treatment. Taking this fact into account we suggest algorithm of situation feed correction for forming effective cycle of round grinding with radial feed, allowing maintaining process productiveness and preventing thermal defects.

This paper presents an investigation of possibilities of using regression analysis and genetic algorithms in modelling the cutting force values in cylindrical grinding. The process included measurement of cutting forces during cylindrical grinding and later calculating their values using abovementioned techniques. It was concluded that both techniques can be used for cutting forces modelling with genetic algorithms having a slight advantage.