Internal Cylindrical Surfaces Research Articles

Accuracy of the geometric shape of the hole in the longitudinal section during honing

The wide application of honing as a finishing treatment of internal cylindrical surfaces for cylinder-piston systems, used in some structures, is caused by high accuracy measured in tenths of a micrometer, and high productivity of the process. The most important indicator of reliable operation of cylinder-piston systems are high requirements for the geometric accuracy of holes. Due to the lack of sufficient theoretical justification for the selection of honing parameters ensuring the accuracy of the geometric shape of the hole in the longitudinal section, the authors proposed a model for the formation of errors in the geometric shape of the hole. The model is built on the kinematic characteristics of the process including the ratio of the honing stone dimensions, the length of the hole, the stroke of the honing head, the ratio of the speeds of translational and rotational movements, and the force action in the processing zone, which changed due to the presence of an overrun of the honing stone. To obtain analytical dependencies ensuring the minimisation of form deviations, the conditions for stock removal for the points of the machined surface were considered, the value of which was taken proportional to the path of movement, and the pressure value. For this purpose, graphs of the distribution functions of displacements and pressure changes were constructed depending on the coordinate of the point location on the generating line of the hole being machined. Using the obtained analytical dependencies, the potential occurrence of a shape error in the form of a saddle shape was found, the dominant factor influencing the value of which is the value of the honing stone overrun. At the same time, it was identified that the ratio of the speeds of translational and rotational movements has an insignificant effect on the violation of the form in the longitudinal section.

Increasing the efficiency of machines and mechanisms of the agro-industrial complex using sliding bearings with curvilinear generators of the internal cylindrical surface

Sliding bearings with curved internal cylindrical surfaces have great potential and can play an important role in the repair and restoration of mechanisms of the agro-industrial complex. Since their use is becoming more and more common, there is a need to improve the design of such bearings to ensure their quality use and avoid errors in research on this issue, in addition, achieving better results in this area require significant financial investments to improve the efficiency of such mechanisms. The main goal of this work is to provide recommendations aimed at eliminating errors in the processes of improving and improving the quality of sliding bearings, as well as analyzing the functioning of machines used in the agro-industrial complex. An analytical method, a classification method, a functional method, a statistical method, and a synthesis method were used. In the course of the research, the peculiarities and differences of sliding bearings with curvilinear generators of the internal cylindrical surface were noted, errors and their causes, which are allowed during the improvement of agro-industrial mechanisms that ensure the development of the agricultural industry, were analyzed. It is important to analyze the functioning of these mechanisms in order to assess their effectiveness, development and complexity of work during the production of agricultural products. The issue of evaluating the performance of sliding bearings of this type, the expediency of using this element, their limitations during the process, the impact of limitations on the result was considered, and recommendations were proposed that would contribute to an effective mechanism for regulating the issue. It was determined that the use of sliding bearings of this type, in the process of restoring agro-industrial mechanisms, will ensure a significant increase in the productivity of these machines. The practical value of this work lies in the possibility of applying the obtained results to eliminate errors in the development and improvement of the mechanisms of the agro-industrial complex, studying the reliability of the use of sliding bearings in general, taking into account various factors, will provide a basis for recommendations on the appropriate use of these bearings

Experimental study for optimizing superfinishing process parameters of high-quality alloy bearing steel

Superfinishing is one of the methods of high-quality surface machining of elements subjected to high surface wear. It is used for machining external and internal cylindrical surfaces using various models of tools. This experimental study was aimed at determining the effect of machining parameters on surface roughness of high-quality alloy bearing steel. The factors considered were angle of crosshatch pattern (realized by the rotational speed at constant velocity and oscillation), machining time, and pressure of the tool on the machined surface. The experiment was carried out according to the analysis planned for two tools with granulations of 500 and 800. The polynomial and exponential regression equations for subsequent roughness and performance parameters were determined statistically. The multidimensional correlations based on the t-student distribution were established. The results showed that the optimum surface quality depended on the process parameters: grain size, machining time, crosshatch angle, and the contact pressure. The time at which the machining process starts to stabilize with a steady surface roughness was determined to be 120 s. The maximum enhancement of surface roughness was 75% for crosshatch angle of 13°, contact pressure of 0.21 MPa, and granulation of 800. For both 500 and 800 granulations, the diameter loss was in the range of 1–12 microns.

Finite element analysis of viscoelastic media used in abrasive flow machining process

The surface roughness of a part is the most important parameter in view of tribological applications and it also affects the working life of the part during application. The abrasive flow machining (AFM) process is an advanced non-conventional finishing process, used to deburr, polish, and to remove the recast layer from the surface as well as at the edges of the components. In AFM viscoelastic media is used to finish the workpiece with close dimensional tolerance and precision. The viscoelastic media used in the AFM process is laden with abrasive particles. In the present work, a finite element analysis of viscoelastic abrasive media is performed considering the AFM process. A mixture of polyborosiloxane and silicon carbide is used as viscoelastic abrasive media and the AFM process is modeled using ANSYS Polyflow. In the analysis, the flow of viscoelastic abrasive media is assumed to follow the Maxwell model of viscoelastic fluid. The simulations were performed for varying the extrusion pressure for the finishing of an internal cylindrical surface. The results of the simulations were validated with the experimental observation and found in good agreement.

ТОЧНОЕ РЕШЕНИЕ ЗАДАЧИ О РЕЛАКСАЦИИ НАПРЯЖЕНИЙ В ТОЛСТОСТЕННОЙ ТРУБЕ ИЗ НЕЛИНЕЙНО ВЯЗКОУПРУГОГО МАТЕРИАЛА, ПОДЧИНЯЮЩЕГОСЯ СООТНОШЕНИЮ РАБОТНОВА

We constructed and studied analytically the exact solution of the quasi-static boundary value problem for a hollow cylinder (a tube) made of physically nonlinear homogeneous isotropic viscoelastic material obeying the Rabotnov constitutive equation with two arbitrary material functions (a creep compliance and a function which governs physical nonlinearity). A time-dependent displacement and zero shear stresses are given on the inside cylinder surface, a pressure (normal stress) is given on outside surface and zero axial displacements and zero shear stresses are preset on the end cross sections of the tube (thus, cylinder stress and plain strain are realized in a tube). We supposed that a material is incompressible and that given boundary displacement and pressure vary slowly enough with time to neglect inertia terms in the equilibrium equations. We obtained explicit expressions for strains and stresses at any point via the ratio of a tube radii, given external pressure and integral operators involving composition of two material functions of the constitutive relation and displacement preset on the internal cylindrical surface. In particular, assuming given boundary displacement and pressure are constant we considered the stress relaxation problem. For arbitrary material functions, we calculated all the hereditary integrals involved in the general representation for the stress field and reduced it to simple algebraic formulas convenient for analysis and use. We studied analytically general properties of the stress relaxation curves at any point of a tube and features of stress distributions along radius. We proved that the first material function (relaxation modulus) of the constitutive equation governs completely stresses dependence on time and the second one (non-linearity function) governs only stresses dependence on radial coordinate and found out that hoop stress and axial stress can change sign and can increase, decrease and be non-monotone with respect to radial coordinate. In case of zero external pressure, we proved that all stress relaxation curves at any point of a tube are proportional to each other (ratio of stresses at different points doesn't depend on time), decrease with time and have no flexure points. We also calculated integral mean values of axial and hoop stresses and discovered that their ratio depends on thickness/radius ratio only and doesn't depend on time and material functions although mean stresses do.

Динаміка відносних крутильних коливань при формуванні регулярного мікрорельєфу на внутрішніх циліндричних поверхнях

An analysis of modern literature sources to search for mathematical models describing the dynamics of the process of forming a regular microrelief on the inner cylindrical surface of parts, gas transmission equipment operating in severe operating conditions, in order to increase their life. It is established that there are no mathematical models describing this process and the peculiarities of its implementation under the point action of the deforming element on the workpiece surface. The molding movements accompanying the process of forming a regular microrelief on the inner cylindrical surface of the workpiece are considered and the driving forces that accompany this process are analyzed. On the basis of the conducted analysis the mathematical model of dynamic process of formation of a regular microrelief on an internal cylindrical surface of a detail is developed. The peculiarity of this process is that the process of microrelief formation occurs by a concentrated force, the point of application of which in relation to the part is constantly changing in radial and axial directions, and then the mathematical model describing this process will be with a discrete right. It is proposed to model such an action using Dirac delta functions with linear and temporal variables, using the method of regularization of these features, in particular, existing methods of integrating the corresponding nonlinear mathematical models of torsional oscillations of a part. Analytical dependences are obtained, which describe these oscillations in the process of formation of a regular microrelief. Using Maple software, 3D changes in the torsion angle depending on different output values are constructed. The conducted researches will allow to consider torsional fluctuations that is especially actual for long cylindrical details, such as sleeves of hydraulic cylinders, details of drilling mechanisms and others.

Modification Hydrodynamic Properties of Narrowing Down Devices of Flow Sensors from Action of an Abrasive Wear

In operation the outcomes of study influencing an abrasive wear of working surfaces of a cylindrical nozzle on operation of a flow sensor of variable pressure differential are introduced. The outcomes are obtained by a numerical modelling of current of fluid through a nozzle. For a nozzle the internal cylindrical surface is resized up to a taper and circularization on radius a crimp on an input. Simulation executed by a finite element method with usage of the program Ansys 5.5ED. Budgeting of numerical experiment and treating of outcomes have fulfilled with applying of the program Stastistica 6.1.The quantitative estimation of influencing an abrasive wear on variation coefficient of the outflow of flow sensors is obtained.

Estimation of the Elasticity Modulus of Composite Electroplated Coatings during Their Layer-by-Layer Deposition

Introduction. To keep automobiles and tractors in operation conditions, it is necessary to restore the inner cylindrical surfaces of the friction pair parts. This is the most laborintensive activity. The method of electroplated contact deposition of composite coatings, based on elastic plastic deformation of formed layers, is used for repairing surfaces. To use this method it is necessary to determine the values of the elasticity modulus, on which the wear resistance of tribocouplings depends. Materials and Methods. For the study, cylindrical samples made of 30 HGSA and 30 HGSNA steels were used. Electrolyte containing 200–250 g/l chromium oxide, 2.0–2.5 g/l sulfuric acid, and distilled water was used for electroplating the coatings. When calculating the stress-strain state, the apparatus of continuum mechanics was used. Results. The dependence of the coating pliability as a function of the parameters of individual elementary layers is determined. When the multilayer coating of three types (orthogonal-reinforced, cross-reinforced and quasi-isotropic) is applied, its structure does not depend on the angles of kinematic tool movement on the inner cylindrical surface of the part. For each type of coatings, the way to determine the constant stiffness coefficients of the layers is specified. The dependences for calculating the elasticity modulus of the applied material are derived from the values of the stiffness coefficients. Discussion and Conclusion. In determining the modulus of elasticity of multilayered composite coatings, the calculation is made for the individual layers by passing to the convective coordinates, which is in complete agreement with the Lagrange point of view on the study of the motion of a continuous medium. The results obtained are of practical significance in the selection of the coating material to be applied for the restoration of internal cylindrical surfaces.

Elaboration of a lubrication system for universal spindle hinges of rolling mills

The experience of running drives of most of heavy-duty rolling mills shows that the designs of universal spindles with blade hinges under conditions of increased alternating loads are most acceptable comparing with other spindles types. Open friction surfaces are the drawbacks of these types of spindles, which complicate the matter of continuous supply of lubrication. Perfected effective system of forced lubrication of rolling mill spindles hinges proposed. The facility for their lubrication has a bearing support of balancing design, spindle, in radial holes of which spring-loaded plungers are installed in a diametrically opposite order. Besides, the facility has suction valves and force valves installed in the spindle axial holes, connecting with the radial ones. A methodology proposed to select the eccentricity of the internal cylindrical surface of the bearing support of the spindle hinge, the axis of which is located eccentrically relative the spindle rotation axis. A calculating scheme and a mathematical model of the process of lubrication supply into joints of rolling mill spindle hinge elaborated. A differential equation of lubrication motion in the conical slot of the hinge between a blade and insertions drawn up. Parameters of hydrodynamic motion of lubrication in the conical slot established. Modes of the lubrication motion in the conical slot between roller blade and hinge insertion determined. Based on experience of operation of friction couple bronze-steel, a lubrication for rolling mills universal spindles proposed. To improve the operation characteristics of hinges based on the friction couple bronze-steel, a thick lubrication having antifriction properties namely based on oils with additives ИП-10, КП-10 and ДФ-11 proposed. Dependence of pressure distribution along the length of the hinge conical slot presented for various lubrications of low viscosity (ИП-10 + ДФ-11) and high viscosity (КП-10 + ДФ-11). The quality effect of the speed of roller blade movable wall on distribution of speeds of lubrication layer motion over the height of the hinge conical slot for comparatively low and comparatively high boundary speeds demonstrated.

Mathematical modelling of heating features of a cylindrical surface under plasma deposition

Mathematical model for temperature determination in a system ‘coating – base’ under plasma deposition of a powder material on the internal cylindrical surface has been developed. Mathematical model takes into account transformation of Gauss heat source, relative motion velocity of a plasmatron, and an angle of a plasma jet relative to the deposition surface. Effect of process variables of deposition on the process thermal stress and quality of plasma coatings has been analyzed.

Dynamics of relative torsional vibrations in the formation of a regular microrelief on internal cylindrical surfaces

The article presents the results of analysis of modern literature sources in search of mathematical models describing the dynamics of the process of forming regular microrelief on the inner cylindrical surfaces of parts operating in difficult conditions, in order to increase their life cycle. The absence of mathematical models describing this process and the peculiarities of its implementation with the point action of the deforming element on the surface of the body part are established. The movements of the tool during the process of forming a regular microrelief on the inner cylindrical surface of the body of the part are considered and the driving forces that follow this process are analyzed. Based on the results of the analysis, a mathematical model of the dynamic process of forming regular microrelief on the inner cylindrical surface of the body of the part was developed. The peculiarity of this process is that microrelief is formed by concentrated force, the point of application of which is constantly changing in the radial and axial directions relative to the part. Therefore, the mathematical model that describes this process will have a discrete right-hand side. It is proposed to model such an action using Dirac delta functions with linear and temporal variables, using the method of regularization of these features, in particular, existing methods of integrating the corresponding nonlinear mathematical models of torsional vibrations of a part. Analytical relations describing these vibrations in the process of forming a regular microrelief are obtained. Using Maple software 3D changes in torsion angle depending on different values of the source data are constructed. The conducted research will allow to consider torsional oscillations that is crucial for long cylindrical details, such as sleeves of hydraulic cylinders, parts of drilling mechanisms and others.

О разработке электромеханического привода с шарико-винтовой передачей, защищенной от заклинивания

At present, one of the most pressing issues is the problem of improving electromechanical drive reliability, specifically, eliminating the possibility of jamming in the ball screw. The paper proposes an engineering solution designed to replace expensive imported ball screws. We analysed alternative designs intended to improve electromechanical drive reliability. We proposed and patented a ball screw design featuring a separator, in which the nut acts as a piston. The structure consists of a smooth cylindrical body and a slotted separator, its slots positioned along a helical line with a step equal to the thread lead. The body and the separator are coaxial and rigidly fixed together at the separator end faces so that the rolling elements remain in contact with the screw thread surfaces, the internal smooth cylindrical surface of the nut body and the surfaces of the separator slots. The ball screw design proposed, which features a nut with no internal threading, significantly simplifies the structure and its manufacturing technology. We built a model of an electromechanical drive equipped with a recirculating ball screw in order to determine static and dynamic properties of an electromechanical drive containing a ball screw featuring a separator. We compared the strength of the ball screw designs considered. As the ball screw featuring a separator is simpler and more reliable, the results of our analysis and the properties of an electromechanical drive equipped with the design proposed show that it is a promising solution to the import substitution problem concerning recirculating ball screws

KINEMATIC FEATURES OF THE LAPPING PROCESS AND DETERMINATION OF ITS BASIC PARAMETERS

This paper discusses the kinematic characteristics of lapping process and the main parameters of the process. It was determined that the influencing degree of technological parameters to the forming surface and processes. It was projected the construction of the lapping head for processing of internal cylindrical surfaces, scheme of the lapping operation and graphic description of the forces influencing. The relationships between the axial, radial and tangential cutting forces and the effect of the combined force thereof are determined in order to ensure the necessary surface pressure. During the analysis geometric and mathematical relationships were obtained. The extracted analytical expressions can be realized by further experimental researches and can be used in engineering calculations of technological parameters of processing by lapping. Angular velocity, friction force, linear velocity, also the length of the tactile curve and the radius of the part can be considered the main kinematic and dynamic parameters of the process that the formation of the surface, also the course of the process depends on these parameters. Depending on the kinematic parameters, the wear nature of the tool changes and this changes the linear and angular velocities, which have a significant impact on the accuracy, quality and productivity of processing. When examining the technological capabilities of the process, the nature of the movement between the part and the grinding tool, also changes in cutting speed are often considered as a main factor. Analytical expressions were obtained to determine the main parameters of the process, taking into account the kinematic characteristics of the friction process. These expressions can be used in engineering calculations and allow to determine the optimal values of the processing mode. In order to obtain the required micrometric surface cleanliness and measurement accuracy, correlation relationships were established between the main parameters of the process, equations of the equilibrium system of shear forces were compiled and analytical expressions were obtained based on the analysis of kinematic and dynamic properties of the system.

АНАЛІЗ КОНСТРУКЦІЇ ТА ТЕХНОЛОГІЇ ВИГОТОВЛЕННЯ ПЕРСПЕКТИВНИХ РОТОРНО-ПОРШНЕВИХ ДВИГУНІВ

The article discusses the main directions of development of creating new modern and improving existing rotary piston engines. The need for a systematic analysis of existing similar engine designs is established to separate and systematize their advantages and disadvantages at the design stage. As an analysis of the design and manufacturing technology of the existing most promising rotary piston engines, turbocompressor-type circuits with a movable cylinder block is considered, the engines in which the combustion takes place outside the working cylinder, the drum-piston type with movable combustion chambers, rotary expanders, etc. It is established that the structure of the housing of rotary piston engines with an internal cylindrical surface, in which the rotor with working cylinders is located, allows the creation of economical and compact engines. This structure of the engines allows you to reduce vibration and make them safer to use. A comparison of the mechanisms of motion of existing rotary piston engines. Based on the analysis of existing schemes and the design of modern rotary piston engines, a sample of a new design 12 RPE-4.4/1.75 rotary piston engine is designed. The design and basic parameters of a new model of the 12 RPE-4.4/1.75 rotary piston engine with adjustable spool air distribution are presented. The engine has twelve evenly spaced cylinders, provides a balanced engine, and the ability to start at any position of the rotor. The design of the engine designed provides for a central control cam shaft, the rotation of which allows you to adjust the valve timing and engine operation due to the degree of filling of the cylinder in a fairly wide range. A feature of the design of the engine is also that the control cam allows you to change the direction of rotation of the central rotor. It was found that the design of the crank mechanism of the 12 RPE-4.4/1.75 engine is simple in structure and production technology, as well as more reliable compared to similar existing rotary piston engines.

Experimental analysis of magnetorheological finishing of blind hole surfaces using permanent magnet designed tools

Permanent mould dies are used for various plastic injection moulding products. Most of the mould cavity is blind and henceforth difficult to finish. In this study, a novel magnetorheological fluid-based finishing process using permanent magnet tools has been developed for nano-finishing of cylindrical blind hole surfaces. Tools to finish the internal and flat-bottomed surfaces of the cylindrical blind hole are developed. The finishing performance of both tools is evaluated for finishing ferromagnetic material used in dies. The material of the die is P20 tool steel having 41 HRC hardness. Response surface methodology using a central composite design technique has been utilized for the plan of experiments and analysis of significant process parameters on the percentage change in surface roughness using newly developed tools. During finishing the internal cylindrical blind hole surface, the process parameters like rotational speed, reciprocation speed and abrasive mesh size are found to be significant. However, during flat-bottomed surface finishing of cylindrical blind hole workpiece, rotational speed, abrasive mesh size and abrasives volume percentage are found to process significant parameters. Experimentation at optimized parameters results in the final surface finish of 83 nm on internal cylindrical surface and 93 nm on the flat-bottomed surface of cylindrical blind hole workpiece.

Experimental Study on Abrasive Flow Machining (AFM): New Approach for Investigation on Nano-SiC in the Improvement of Material Removal and Surface Finishing

The latest improvement in the usage of good strength, hard, and high-temperature-resistant materials in manufacturing required the advancement of modern machining methods. The AFM (abrasive flow machining) is a non-conventional finishing technique within which an abrasive viscoelastic polymer is pressed around the surface area of the workpiece. An AFM experimental arrangement is manufactured and designed along with highly generated media in order to finish the internal cylindrical surface areas of Al7075/SiC NMMCs. Work pieces are made by means of lathe operation soon after stir casting metal matrix nanocomposites, 25 mm diameter crossbar of 1%, 2%, 3%, and 4% nano-SiC (50 nm) by weight. The effect of abrasive flow machining process parameters, namely, extrusion pressure, abrasive mesh size, and the number of cycles on surface roughness (ΔRa) and material removal (MR) was evaluated. The mechanical properties such as hardness, tensile strength, and density are calculated. The scanning electron microscopy (SEM), OM, EDS, and XRD analysis additionally show the enhancement in the surface finish of these NMMCs.

Magnetic abrasive flow finishing: A review

In these decades, there has been an increasing demand for magnetic field-assisted surface finishing processes in the industries. It is due to specific features available in the magnetic assisted surface finishing process; these are contactless and effectively controlling of magnetic forces in the intricate passage. These processes are hybridized by modification in the existing conventional surface finishing process or by clubbing two or more unconventional surface finishing processes. Magnetic Abrasive Flow Finishing (abbreviated as MAFF) process is an unconventional process used for internal cylindrical surface finishing, intricate and complex inside profile geometry. It is a hybrid process that gives a combined effect of AFM and the MAF process. MAFF was developed by the researchers Sahijpal Singh and H.S. Shan in the 2000s. They modified the AFM by applied an electromagnet around the workpiece. The main drawbacks of AFM’s process were low material removal rate and time-consuming process. MAFF was an advancement of AFM, in MAFF process material removal and surface finishing both considerable optimize. MAFF has a broader range of applications in electronics manufacturing of aerospace, semiconductor, automotive components, and medical components like biopsy needle.

Разработка конструкции для наплавки внутренних цилиндрических поверхностей

Разработка конструкции для наплавки внутренних цилиндрических поверхностей

Surface microgeometry treated with a precast textured grinding wheel

The article considers the formation of the geometry of internal cylindrical surfaces when grinding with a precast textured wheel, which is under the influence of the unbalances main vector and a variable cutting force caused by the discreteness of the cutting surface (texture). Under the influence of these factors, each point of the axis of the textured tool makes vibrations in the transverse plane in the form of a wavelike sinusoid consisting of two sinusoids. The Space-time process of forming the processed surface is mathematically described. It is in applying wavelike sinusoids to the workpiece, taking into account their phase shift at each revolution of the workpiece. To ensure minimal geometric errors at the maximum possible productivity of the grinding process, phase shifts φf = (0.07–0.12)π and φf = (0.88–0.93)π are recommended. The results of the study are recommended for use in the production of high-precision details, primarily from materials that are prone to thermal damage to the surface layer under the influence of high temperature in the grinding zone.

Theoretical and experimental investigations on nano-finishing of internal cylindrical surfaces with a newly developed rotational magnetorheological honing process

In the current scenario, the advanced industries are using highly sophisticated types of machinery. These types of machinery use numerous cylindrical components made with superior materials and technology. For obtaining the nano-level finished interior cylindrical surface with high accuracy and high production rate, a newly developed rotational magnetorheological honing (R-MRH) process is employed on the cylindrical objects. This process is applicable in internal nano-finishing of cylindrical molds, hydraulic and pneumatic valves, aerodynamic bearings, gears, cylindrical barrel, and cylinders used in medical devices, etc. In the present work, the cylindrical workpiece is also made rotational in the reverse direction of the MRH-tool rotation unlike the existing MRH process. The rotating motion of the workpiece cylinder caused an increment in relative motion of the active abrasive particles against the interior surface of the workpiece cylinder. The effect of the rotational speed of the workpiece cylinder along with movements of the MRH-tool on change in surface roughness is investigated theoretically and experimentally in this work. Theoretically, it is found that the simultaneous motions of tool and cylindrical workpiece in the opposite direction to each other increase the finishing rate. To validate the theoretically increased finishing rate due to the rotating cylindrical workpiece, and to examine the effect of the rotational motion of the cylindrical workpiece on finishing performance, the experiments are conducted with the R-MRH process. The reduction in surface roughness is found as 71.71% in 60 min with the existing MRH process for the stationary cylindrical workpiece, whereas it is reduced to 83.83% in only 40 min with the R-MRH process for the rotational cylindrical workpiece. The significant change in surface roughness value with reduced finishing time validates the improved efficacy of present R-MRH process for its more utility in industries.