Rounding Radius Research Articles

Study of the effect of sharpness of cutting tools on the formation of defects in the surface finish in micro cutting titanium alloys

The quality of machining of titanium alloys in the aviation and medical fields, characterized by the presence of micro vias, scales and surfacing on the treated surface, as well as the level of roughness is important in the manufacture of key parts. The quality parameters of the treated surface are influenced by many factors - cutting modes (cutting speed, depth and feed), cutting tool parameters (geometry of the cutting part, hardening coating, sharpness of the cutting wedge, etc.), technological equipment parameters (rigidity and accuracy), etc. The aim of the work was investigation of treated surface of titanium alloy VT1-00 when milling with small thicknesses of the shear layer, commensurate with the sharpness of the cutting wedge of the cutter. Method. The method of investigation of the treated surface during milling of titanium alloy on the micro level with the use of standard and high-quality carbide cutting tools is proposed. Results. Operating experience of the received carbide tool has shown that sharpness of a cutting wedge influences quality of the processed surface characterized by microwaves, scales and burrs, also by the roughness of the treated surface. On the basis of carried out researches it is established that for maintenance of conditions of normal cutting and chip formation it is necessary to provide sharpness of the cutting wedge characterized by the conditional entered radius of a blade rounding having values less than values of the sizes of grains of a processed material, that is re < 5 μm. Field of application. The obtained results of work allow to substantiate the recommendations on the required sharpness of carbide cutting tools used for milling of titanium alloys at the micro level. Conclusions. Experiments on the study of the process of cutting of titanium alloy VT1-00 at the micro level to determine the effect of cutting tool sharpness on the quality of the treated surface (microwaves, scales and burrs), allow to form recommendations on its initial state and determine performance.

Application of a Special Profile Deforming Tool for Intensification of the Extrusion Process in Radial Matrixes

Calculated analysis of the extraction of axisymmetric hollow products from low carbon steel using a special profile deforming tool were carried out by the Finite Element Method. An elastic-plastic model of the workpiece metal was used. Coulomb friction, hardening, deformation rate and thermal effect during cold forming are considered. A special profile of the tool is a wavy surface, which is formed by the intersection of tori with the same diameter of the section, located with a certain step. Special profile of the Matrix and the clamp provided a decrease in the effect of friction on the drawing force. The special profile punch creates a pulling force behind the wall of the deformed workpiece in the gap between the matrix and the punch due to the filling of cavities with metal on its side-surface. Unloading of the bottom of the workpiece occurs by the amount of pulling force. The smoothing of the protrusions on the inner surface of the deformed workpiece is carried out during the reverse movement of the punch of a special profile and removing the product. The use of a special profile tool has reduced the number of draw transitions for low-carbon steel products by half. At the same time, it was possible to draw with thinning the wall, which provided a decrease in the wall thickness variations. Possibility of extraction by a punch with a radius of rounding, which is two times less in comparison with the extraction of a traditional tool. This eliminates the additional operation of calibrating products after drawing. For the considered options for drawing with different gaps between the die and the punch, the dependences of the drawing forces, the forces on the clamps and the forces of removing products from the punches are established. The stress-strain state of the workpieces and the temperature of the deformed metal were revealed. Particular attention is paid to axial tensile stresses, which are the main reason for the separation of the bottom of the product. The shape and dimensions of the products after drawing are determined.

A method for evaluating the edge strength of soil-cutting parts of forestry machines

One of the main factors that determine the resistance of blade working bodies against damage under dynamic loads is their resistance to plastic crumpling, brittle or fatigue failure. Hard alloys that strengthen the blades of tillage parts are more brittle materials than steel, so the blunting of their edges is caused by the formation of cracks, their gradual growth or microchipping, even from a possible single impact of a solid inclusion in the soil. In addition to the usual brittle fracture of hard alloys, fatigue failure occurs under cyclic impact conditions. (Research purpose) The research purpose is in identifying the pattern of destruction of the blade edge of soil-cutting parts of forestry machines and theoretically justifying the algorithm for assessing the strength to determine the rational thickness of the wear-resistant coating during hardening. (Materials and methods) The article presents the main regularities of the influence of material properties and geometric parameters of the blade on the radius of rounding. (Results and discussion) The process of breaking the edge of the blade of hardened working bodies of forestry machines has been studied. The claim that the blunting of the blades is mainly due to its destruction and not to wear has been proved. The article presents a method for evaluating the strength of bimetallic blades of soil-cutting parts of forestry machines. It was found that the blunting of the blade occurs as a result of edge destruction in the process of multiple impacts of solid soil inclusions along the edge of the blade. (Conclusions) The article shows that the destruction of the edge of the blade leads to blunting of soil-cutting parts, which affects their performance. It was found that the sharpness of a self-sharpening hardened blade is determined by the thickness of the reinforcing layer and its ability to resist destruction under impact.

ОСОБЛИВОСТІ ВИГОТОВЛЕННЯ РОТОРА ДЛЯ ПОПЛАВКОВОГО ГІРОСКОПА В УМОВАХ ВИРОБНИЦТВА

The problem of ensuring the performance of high-precision parts of navigation systems, while forming their surfaces by turning, has become extremely urgent today. The use of wide-ranging numerically controlled machine tools for precision spherical surfaces is promising, provided the required shape accuracy and roughness are required. Practical experience with the use of synthetic single-crystal interchangeable diamond plates has shown the need to find technological solutions related to reducing the surface roughness under certain conditions. The article presents the basic data on the technological capabilities of instrument production of manufacturing the parts for mechanical gyros-copes. The algorithm and technological sequence of manufacturing and providing the necessary properties to the surfaces of gyroscope rotor parts made of D16 and B95 aluminum alloys are presented. A description of the manufacturing sequence is given, indicating the tools and equipment used during the operation. A detailed description of geometric parameters of the variable plates with the indica-tion of manufacturers is given. A series of experiments has been conducted to determine the cutting modes by carbide and diamond tools. The influence of flow, speed and depth of cutting have been determined to ensure the minimum roughness of spherical surface of float gyroscope rotor for specific processing conditions. The results of the roughness measurements after polishing the surface obtained with diamond sharpening are presented. The results obtained can be used in the production, in the design of technological processes for the manufacture of parts made of aluminum alloys which have high-precision spherical surfaces. In addition, additional confirmation of the influence of the radius of rounding of the main cutting edge on the roughness of the machined surface has been obtained.

ТЕХНОЛОГИЧЕСКИЙ ПРОЦЕСС ОБРАБОТКИ КОМПОЗИТОВ С ПРИМЕНЕНИЕМ РАЗРАБОТАННОЙ КОНСТРУКЦИИ РЕЗЦА ДЛЯ ЧЕРНОВОГО ТОЧЕНИЯ

The article considers the technological process of mechanical processing of composite materials. The characteristic of composite materials and their physical and mechanical properties is given. The rationale for the need to improve the design of the cutting tool is given. The design of the cutting head has been developed for the cutting process. It consists of a rough and finishing incisors. To determine the optimal geometry of these incisors, 20 incisors of each type were manufactured with a modified geometry. Experiments with changing the values of the back and front corners were carried out. Recommended minimum front angle values for soft and hard materials. The radius of rounding of the roughing tool is recommended. The technological process of processing composite materials is given. The design of the roughing tool is described in detail, which largely eliminates the disadvantages of processing, increases productivity, improves quality, and increases durability.

Parameter optimization of a micro-textured ball-end milling cutter with blunt round edge

Titanium alloys is a typical difficult-to-cut material with many machining problems, build-up-edge, large cutting force, and high cutting heat. Previous research has shown that micro-texture on the tool surface can solve the above problems potentially, and that a blunt round edge of the cutting tool can enhance its strength and improve the tool wear resistance. Therefore, towards an optimal parameter of micro-texture and blunt round radius, a finite element method (FEM) simulation and an experiment are carried out, where the test result provides a set of data for a genetic algorithm–based prediction model. The optimized parameter combinations of the micro-textured ball-end milling cutter with a blunt round edge are obtained and compared in a set of experiments. The optimized parameters refer to a 40-μm radius of the blunt round edge, a 40-μm micro-texture diameter, a 175-μm spacing, a 120-μm distance from the cutting edge, and an 80-μm depth.

Design and Characterization of Area-Efficient Trench Termination for 4H-SiC Devices

In this paper, the operation mechanism of trench termination is investigated through 2-D numeric simulation on Silvaco. It is found that in trench termination, the electric field is terminated by the accumulated holes at the outer trench sidewall. In order to ensure a high termination breakdown voltage, the trench is refilled with a combination of SiO2 and polyimide (PI). Through various 2-D numerical simulations, the impact of structural parameters on breakdown voltage has been discussed, namely, trench depth (TD), trench width (TW), and sidewall tilt angle. The 3-D simulations are also conducted to investigate the effect of round corner radius on the device breakdown voltage and electric field in the dielectrics. Based on these results, the trench termination is designed and then fabricated along with a p-i-n diode. The measurement results show that a $14~\mu \text{m}$ wide trench is sufficient to terminate a voltage of 1750V (>96% of the ideal planar breakdown). Comparing with conventional field limiting rings junction termination extension (FLR/JTE) technology, this trench termination can significantly reduce the termination length by a factor of 4. As a result, the area efficiency is largely improved from 62% to around 90% for a 2A device conducting at 1000 A/cm2. These results indicate that the SiC device price can be substantially lowered with such an area-efficient trench termination technology. Furthermore, the 168-h high-temperature reverse bias (HTRB) test under 1200 V and 175 °C shows the potential of this trench termination for long-term reliable operation. Finally, unclamped inductive switching (UIS) tests have been conducted on fabricated devices. Compared to commercial SiC junction barrier Schottky diodes with FLR, fabricated p-i-n diodes with trench termination show significant higher avalanche capability.

Change in Limiting Channel Dimensions during Pneumatic Shaping of Multilayer Structures

A mathematical model is developed for determining the inert-gas pressure within rectangular channels in multilayer structures. The model permits calculation of the pressure, stress, and damage in the shaping of materials with different properties. The influence of the relative channel height on the relative limiting rounding radius of a corner element and the membrane thickness and also on the failure time for titanium (VT6S) and aluminum (AMg6) alloys is investigated. The deformation processes are described by the energetic and kinetic theories of creep and damage for viscous flow.

Ultra-high-speed sharpening and hardening the coating of carbide metal-cutting tools for finishing aircraft parts made of titanium alloys

The work is devoted to the creation of a hard-alloy tool for finishing processing of heat-resistant and titanium alloys. Objective: to increase the efficiency of carbide blade tools for finishing machining of aircraft parts of heat-resistant and titanium alloys by means of ultrafast grinding, to determine the method of hardening the cutting part and the conditions of its operation. Subject of the research: the quality of the cutting wedge (conditional inscribed radius of the blade rounding, the presence of microchips, blockages and microhardness) obtained by ultrafast grinding and work-hardening of the cutting part and the determination of the conditions of its operation. Objectives: to implement the method of carbide tools ultrafast sharpening, providing the required quality of the cutting wedge, characterized by the conditional inscribed radius of rounding of the blade, the presence of microchips, blockages and microhardness, capable of producing blade processing of parts from heat-resistant and titanium alloys with an accuracy of 3…5 microns and roughness of Ra 0.2…0.4 microns; to investigate the process of superfast sharpening and to determine the effect of sharpening modes of carbide metal cutting tools on the quality of the sharpened tools cutting wedge; to investigate the reason for the reduction of the durability of the cutting tool while reducing the rounding radius of the blade and to determine the composition of the hardening coating, which slightly reduces the sharpness of the blade; to investigate the influence of cutting modes of finishing heat-resistant and titanium alloys with a tool blade sharpness up to 5 microns on its durability, as well as the surface roughness and accuracy of the part. Research methods: electron microscopy (Jeol JCM-5700, an energy-dispersive spectrometer attachment JED-2300; NTEGRA PRIMA (NT-MDT)); optical microscopy (MikroCad Premium, ODSCAD measurement program; Axio Observer.A1m); vibrodynamic analyzer (DIANA-2M); coating thickness measurement method (Calotest CAT-S-0000); microhardness measurement method (PMT-3 and DM 8 B AFFRI); determination of the characteristics of the tribotechnical properties by the method of testing for friction and wear (II5018); determination of cooling capacity (Compaton). Theoretical and calculation methods: simulation method; end element method; methods of mathematical statistics.

The effect of rounding radius in bump foil structure on the static performance of foil journal bearings

Purpose The purpose of this paper is to investigate the effect of the rounding in bump foil on the static performance of air foil journal bearings. Design/methodology/approach During the study, the bending moment of the new foil structure with rounding is proposed, and the bump foil stiffness is obtained from the elastic deformation energy theory. The validity of the presented foil model is verified through comparison with previous models. The static characteristics of foil bearings such as film thickness and attitude angle are obtained using a fully coupled elastic-gas algorithm and are compared to models with various rounding radius and friction coefficients. Findings There is an optimal rounding radius that makes the stiffness of bump foil maximum. As the static load increases, the minimum film thickness is proportional to the rounding radius but the attitude angle is inversely proportional. The effect of rounding with a large friction coefficient becomes negligible. Originality/value The rounding brings fundamental difference in the structural stiffness and static performance of foil bearings. The results are expected to be helpful to bearing designers, researchers and academicians concerned.

ОСОБЕННОСТИ ФОРМИРОВАНИЯ ШЕРОХОВАТОСТИ СОПРЯЖЕННЫХ ЦИЛИНДРИЧЕСКИХ И ТОРЦОВЫХ ПОВЕРХНОСТЕЙ ДЕТАЛЕЙ ПРИ ИХ ШЛИФОВАНИИ ОДНИМ ИНСТРУМЕНТОМ

The paper reports the study of peculiarities in the roughness formation of conjugate cylindrical and end surfaces of machinery at their simultaneous grind-ing with the disk periphery and the end. &#x0D; The analytical dependences for the computation of altitude and step parameters of surface roughness at simultaneous grinding with disk periphery and butt are obtained the authenticity of which is confirmed in the course of experimental investigations. It is defined that altitude and step roughness parameters of cylindrical surfaces and end surfaces conjugate with them after their simultaneous grinding may differ up to 2-3 times. Lesser roughness is formed on end surfaces which is explained by the large number of disk grain tips contacting with given surfaces of a blank. The roughness step parameters of ground surfaces are influenced considerably by a rounding radius of abrasive grain tips at that the average step of unevenness along a middle line Sm is threefour times greater than the average step S on tips. &#x0D; It is shown that a considerable impact of abrasive tool characteristics and time of surface processing with a grinding disk upon parameters of roughness in conjugate surfaces of parts. &#x0D; Recommendations scientifically substantiated are formulated on the technological support of surface roughness parameter aggregate at simultaneous grind-ing with the disk periphery and the end.

Discharge Coefficient of a Round-Crested Weir

A model experimental study was conducted for the discharge capability of different shapes of the crest of a weir. The flow rate and the head over the weir measured by laboratory experiments were used as two parameters for characterizing the head discharge relationship. Experiments indicated that the head discharge relationship for different radii located upstream and downstream of the crest of the weir had different features. A series of detailed experiments investigated the effects of different upstream rounding radii on the discharge capability when the downstream rounding radius was constant and the round ratio between the radius of the rounded upstream corner to the weir breath in the direction of flow was equal to 1.00. Experimental results showed that the rounded upstream corner could increase the discharge capability. The discharge capability increased as the upstream round ratio became larger and did not change when the round ratio varied from 0.10 to 0.30 and from 0.75 to 1.00 in this experiment. Based on the experimental data distribution, the empirical formula for the discharge coefficient was fitted with the round ratio as the group parameter.

Two-Dimensional Plastic Flow of a Flange when Deep Drawing a Thin-Walled Polygonal Prism

Two-dimensional plastic flow of a flange when deep drawing a thin-walled polygonal prism with a flat bottom of round blank provided with Mises yield criterion based on the theory of plane stress condition according to Sokolovskii is simulated. The slip lines, the stress condition, the hodograph of displacement velocities, and the dissipative function of plastic flow are calculated. The limit parameters of deep drawing are defined by the maximum tensile stress at the mold contour and by zones with negative dissipative function, which depends on the radius of rounding of mold angles and the prism height.

Analytical Stress-Strain Model for FRP-Confined Rectangular RC Columns

One of the major applications of Fiber Reinforced Polymers (FRPs) in construction is in the confinement of reinforced concrete (RC) columns. The performance of FRP-confined concrete in circular columns has been extensively investigated in literature and the efficiency of the available models is nowadays considered to be satisfactory. However, the case of confinement of rectangular RC sections with FRPs is a more complex problem, the mechanism of which has not yet been adequately described. The aim of this work is to simplify the problem by proposing an iterative procedure based on the results of a three-dimensional finite element (3D FEM) analysis. An interesting finding is that the arching effect is not observed: indeed, the unconfined regions are partially confined and contribute a certain amount to the overall strength of the rectangular RC sections. Based on (a) a system of ‘generalized’ springs, (b) well-known stress-strain laws and (c) a failure criterion, a simplified mechanical model which gives the stress-strain behaviour of a rectangular RC section confined by FRPs under concentric load is proposed. The algorithm takes into account all parameters available to designers, such as corner rounding radius, stiffness of the FRP and concrete strength, while it can be easily understood and implemented. Its results are found to correlate adequately to recent experimental data yielded by large-scale tests on FRP-confined rectangular RC columns. Finally, in order to further evaluate the performance of this material model, it was implemented in the simulation of a series of experimental tests of FRP-retrofitted square RC columns under cyclic lateral loading simulating earthquake loads and simultaneous constant axial compression. In particular, all specimens were simulated using nonlinear fiber elements, in which the FRP-confined concrete was modelled using the aforementioned material model. Comparison between the numerical and experimental hysteresis of the column is indicative of the effectiveness of the implemented modelling.

An Investigation Study of Tool Geometry in Single Point Incremental Forming (SPIF) and their effect on Residual Stresses Using ANOVA Model

Incremental forming is a flexible sheet metal forming process which is performed by utilizing simple tools to locally deform a sheet of metal along a predefined tool path without using of dies. This work presents the single point incremental forming process for producing pyramid geometry and studies the effect of tool geometry, tool diameter, and spindle speed on the residual stresses. The residual stresses were measured by ORIONRKS 6000 test measuring instrument. This instrument was used with four angles of (0º,15º,30º, and 45º) and the average value of residual stresses was determined, the value of the residual stress in the original blanks was (10.626 MPa). The X-ray diffraction technology was used to measure the residual stresses. The sheet material used was Aluminum alloy (AL1050) with thickness of (0.9 mm). The experimental tests in this work were done on the computer numerical control (CNC) vertical milling machine. The extracted results from the single point incremental forming process were analyzed using analysis of variance (ANOVA) to predict the effect of forming parameters on the residual stresses. The optimum value of the residual stresses (55.024 MPa) was found when using the flat end with round corner tool and radius of (3 mm), wall angle of (55°) and a rotational speed of the tool of (800 rpm). The minimum value of the residual stresses (24.389MPa) was found when using hemispherical tool with diameter of (12 mm), wall angle of (45°) and a rotational speed of the tool of (800 rpm).&#x0D;

Strengthening of square concrete columns with composite materials. Investigation on the FRP jacket ultimate strain

An accurate estimation of the effective ultimate strain of the FRP jacket is crucial to determine the values of strength and ultimate strain of FRP confined concrete. However, this is one of the main aspects not yet resolved by the theoretical models. Published design recommendations differ on this aspect, particularly in the case of non-circular sections. In this work, an experimental program carried out on 38 square section concrete specimens confined with FRP is presented. The results show a great influence of the radius of rounding of the corners on the behaviour of FRP confined square columns. The experimental values of effective ultimate strain are compared with the recommended values given by design guidelines.

Formability analysis of bearing ring produced by short-flow warm extrusion processing

Bearing rings are the most common used machine parts. It is of great significance to reduce the processing flow of bearing rings for saving energy and material, increasing productivity. In this work, one step warm extrusion processing using ring blank as preform was proposed to form bearing ring which possesses upper and lower rings. The upper and lower rings are formed by materials reverse and forward flow during warm extrusion, respectively, and the ratio of materials reverse flow amount to forward flow amount (RRFA) determines the formability of bearing rings. In order to process bearing rings at optimum RRFA at which the upper and lower rings can be simultaneously formed, finite element models for the warm extrusion processing were established based on DEFORM-3D software. The effect of extrusion ratio, round corner radius of extrusion die, extrusion temperature, friction coefficient on the flow rules of materials was analyzed by the developed finite element models. The results show that small extrusion ratio (i.e. small outer diameter of ring blank) and large round corner radius of extrusion die enhance the material flowing into lower ring and facilitate the forming of lower ring. Extrusion temperature and friction coefficient have little effect on RRFA. Comprehensively considering the flow rules of materials, the well-formed bearing rings can be obtained when extrusion ratio is 2.33, round corner radius of extrusion die is 1.5, extrusion temperature is 700-800 °C.

The influence of the piercing punch profile on the stress distribution on its cutting edge

Modifying the piercing punch profile may have a positive effect on the belt perforation process. Using the proper shape of the tool may reduce the perforation force and improve the quality of the holes. However, complex geometry of the punch can also cause an adverse stress distribution, which leads to a faster tool wear. In the presented paper, several different piercing punch profiles were tested using FEM analyses in ABAQUS and the obtained stress distributions along its cutting edges were analyzed. For the selected group of the piercing punches, the influence of variable geometrical features (a radius of rounding, an angle of chamfering or a depth of the bowl) on the stress distribution were also shown. Based on the results, it is possible to predict how modifying the punch profile will affect the shortening of the tool life, compared to the basic flat-end cylindrical piercing punch. The following research can be useful in the design process of the punching tools used for vacuum conveyor belts perforation.

Numerical Investigation on Effect of Rounded Cutting-Edge Radius and Machining Parameters in End Milling of AISI H13 Tool Steel

Rounded cutting-edge radius is commonly applied to finish and semi-finish cutting, precision machining and micro-machining. The optimum effect is closely related to the work and tool material as well as machining parameters. However, for numerous cutting process, the optimal radius of rounded cutting-edge radius and machining parameters applied in the AISI H13 of end-milling is yet unknown Therefore, in improving tool life and cutting tool performance, a suitable design of cutting edge geometry regarding cutting edge-radius and machining parameters need to be examined and properly selected. In this regard, the paper deals to examine the effect of cutting edge-radius in rounded form and machining parameters of cutting force, cutting temperature and chip formation through the end-milling process of AISI H13 using uncoated cemented carbide cutting tool through finite element simulation of Thirdwave AdvantEdge 7.2 software. The machining parameters applied in the simulation setup were 200 and 240m/min of cutting speed, 0.03 and 0.06mm/tooth of feed-rate and axial depth of cut of 0.1 and 0.2mm while width of cut in radial direction was kept constant at 6.0mm. The cutting geometries includes the cutting-edge radius of 0.03 and 0.05mm and 10° of rake angle. The obtained results revealed that cutting forces and cutting temperature is increase as depth of cut in axial direction and cutting-edge radius increases while increasing value of speed and feed-rate of cutting resulted in decreasing cutting forces but increasing cutting temperature. The maximum cutting temperature is 674.91℃. The value obtained is lesser than the AISI H13 austenitizing temperature, therefore a layer known as white layer is supposedly hard to be created based on the cutting geometry and machining parameters applied.

Influence of processing time of a superhard ceramics sample on surface quality and edge rounding radius

The article shows studies of the influence of vibration treatment time of an abrasive mixture consisting of 15% Type UDD diamond grains and monocorundum, on the surface quality of a sample made of superhard ceramics and the resulting radius of edge rounding. The studied samples were obtained from cubic boron nitride; it being extremely hard in hot state, which makes it possible to use it at very high cutting speeds. It is also characterized by good strength and heat resistance The investigation of the quality of the treated surface, estimated by the magnitude of the residual burr and the height of the microroughness of the surface of the part is very important in the study of vibrating processing of superhard ceramics. In vibration treatment, an increase in the processing capacity does not lead to a deterioration in the surface roughness due to the lapping process, which was achieved by selecting the vibration amplitude. In the process of chip removal during the diamond grinding of ceramics, individual diamond grains are involved, as well as the bundle of the circle. When studying the nature of the destruction of the ceramic surface by diamond grains, it was found that the grain leaves a clear trace without obvious chipping along the edges of the track at the beginning and at the end of the scratch. Diamond grain, having a sufficient hardness, begins to cut the shavings immediately after contact with the material. But the middle part of the scratch along the entire length has significant breaks along the edges. The arising of chips when a certain depth of grain penetration is reached is explained by the fact that with the increase in cutting depth, some new edges of the diamond grain come into operation, which results in the microcutting forces increase in the zone of the contact with the sample material, formation of highly dispersed chips and large breaks. The forces arising during grinding result in good endurance of diamond wheels, high quality of processing, and make it possible to choose rational technical parameters. The necessity of edge rounding can be justified by the complex of tasks facing the technologists. This is the cleanliness of the surface during machining and the cutting edge wear reduction. The cutting edges rounding radius and the speed of its formation are functions of the processing time, size and type of abrasive grain. These parameters are chosen empirically in a specific instance