Profile Milling Research Articles

Investigation of the effect of residual waviness formed by rail profile milling of reshaped surface on wheel-rail contact stresses and low cyclic fatigue

The rail profile milling process allows considerable thickness to be removed in a single pass. However, the residual waviness formation law after milling and its subsequent effect on rail performance remains uncertain. In this paper, the wavelength and wave height of the residual waviness are identified as the key characteristics. The relationship between milling speed and residual waviness is determined, and a numerical model of the residual waviness formed on the surface after milling is established based on the commonly used three milling speeds of 300, 600, and 1000 m/h, and its accuracy is verified using the parameters of the residual waviness detected by the milling experiments. A three-dimensional finite element analysis model of wheel-rail contact was employed to analyze the contact stresses and low fatigue cycles at a wheel load of 11.5 tons with no residual waviness on the rail profile surface and with three types of residual waviness, respectively. The results show that the residual waviness changes the wheel-rail contact position and the morphology of the contact area, reduces the maximum contact stress and increases the strain fatigue cycles. The application of elevated milling speeds reduces the wheel-rail contact stresses after milling, thereby increasing the low fatigue cycles.

Practical Method for Identifying Model Parameters for Machining Error Simulation in End Milling Through Sensor-Less Monitoring and On-Machine Measurement

Depending on cutting conditions, unacceptable machining errors are caused by tool deflection in end milling operations. Many studies have proposed methods for predicting the machining error owing to the tool deflection to achieve the theoretical optimization of the cutting conditions. However, the conventional machining error simulation is not practically utilized to determine the optimal cutting conditions. Tool system stiffness parameters and cutting coefficients must be identified in advance to simulate machining errors. However, dynamometers and displacement sensors are required for parameter identification. Therefore, it is impossible to identify the required parameters in typical factories, which do not possess such special equipment. In this study, a practical method was developed to identify the stiffness parameters that can be determined in factories. The proposed method employs on-machine measurement and sensor-less cutting force monitoring to achieve practical parameter identification. In the proposed method, the profile milling is first conducted. During the milling operation, the cutting force and cutting torque are monitored through a controller based on the sensor-less monitoring technique. After the operation, the machining error distribution on the machined surface is measured on machine using a touch probe. The required parameters are identified by minimizing the differences between the measured and theoretical forces, torques, and machining error distributions.

A feed direction cutting force prediction model and analysis for ceramic matrix composites C/SiC based on rotary ultrasonic profile milling

Ceramic matrix composites have immense applications in the aerospace, aircraft, and automobile industries. Belonging to this class, carbon-fiber reinforced ceramic matrix composites (C/SiC) are used for critical applications due to their superior properties. However, these materials have also stringent properties of heterogeneity, anisotropy, and varying thermal properties that affect machining quality and process efficiency. So, developing a cutting force prediction model and analyzing machining parameters is an essential need for the accurate machining of such materials. In this study, a mechanistic-based feed direction cutting force prediction model for rotary ultrasonic profile milling of C/SiC composites is developed and validated experimentally. The experimental and simulation results closely match each other. The mean error and standard deviation were recorded as 1.358 % and 6.003, respectively. The parametric sensitivity analysis showed that cutting force decreased with increased cutting speed, whereas it increased with increased feed rate and cutting depth. The proposed cutting force model for rotary ultrasonic profile milling of C/SiC composites is robust and can be applied to predict cutting forces and optimize the machining process parameters at the industry level.

Fractal Research on Surface Topography of Profile Milling CFRT

Carbon Fiber Reinforced Thermoplastic Composites (CFRT) are recognized as a new generation of advanced strategic materials due to their excellent mechanical properties and high recycling rate. However, in the milling process, affected by the coupling of force and thermal, the heat-sensitive resin in CFRP is easily softened and deformed, leading to difficulties in achieving high-quality material removal. Especially in the complex and long-period surface milling process, the processed surface has a complex and irregular microscopic topography, hard to be accurately characterized by traditional roughness measurement methods. To evaluate the surface quality of CFRT profile after milling more precisely, in this paper, the influence of cutting parameters on fractal dimension is systematically analyzed by solving the image gray surface based on the fractal dimension algorithm and calculating the fractal dimension of the surface after milling via the variational method. The experimental results show that the surface fractal dimension of thermoplastic composites processed by PCD milling cutter is between 2.46 and 2.52, and the sensitivity ranking of fractal dimension to cutting parameters is: v f<A e<A p.

Tehnologija izrade profilnih koturastih glodala 3+2 osnim brušenjem na horizontalnom obradnom centru

The paper presents the technology of making brazed shaper milling cutters and with special reference to 5-axis grinding process (making of profile blades) on CNC grinding machine tool. Based on the analysis of the kinematics of the 5-axis grinding process, a new concept of profile milling tool production by a 3+2 axis grinding process on horizontal milling center was established. By Applying new concept, one tooth of profile tool was machined by grinding process. By obtained results, new approach for manufacturing of profile milling tools was verified.

An experimental investigation of tool wear rate in end mill HSS-AL with nickel coated tool

End milling is the most flexible type of processing that can be utilized to machine spaces, shoulders, shapes and profiles. An end milling process comprises a round and hollow shaper that has different front lines on the two its outskirts and its tip, allowing end cutting and fringe cutting. A portion of the significant activities should be possible utilizing processing machines they are as per the following external keyway, slotting, sawing, profile milling, helical milling, thread milling, gang milling, face milling, angular milling, end milling. In this venture work, we have utilized the electroplating procedure of nickel on the HSS-Al end mill tool. As indicated by this procedure, Ni is act as anode, HSS-Al end factory instrument is going about as cathode and Ni salt shower is go about as an electrolytic answer for covering. In the wake of covering the measurements, for example, length, the distance across and weight of the instrument have been checked and it is contrasted and the component of ordinary HSS-Al end mill tool. Experimental work has been done in the vertical processing machine with various speeds and the tool used is HSS-Al and HSS-Al Nickel coated end mill tool and the workpiece utilized for the work is gentle steel. The surfaces in the wake of machining were checked utilizing the hardware named surface roughness analyzer to locate the nature of the surface finish. The components of the two tools were noted down after the processing activity. The performance of Ni coated HSS-Al tool has superior to uncoated HSS-Al end mill tool has estimated and the coated toolhas got wear opposition and furthermore it reduces the hour of work to make benefit than the uncoated HSS-Al end mill tool.

Improving the facade element surface processing of MDF case furniture

A lot of enterprises engaged in the production of MDF case furniture face the problem of milled plate surface quality. It ensures the production of facing paper and synthetic film or finishing liquid paints and varnishes to improve the facade element surface processing quality of MDF case furniture. The experiments to study the roughness of MDF plates milled surface have been carried out, depending on the feed rate and tool rotation frequency. The work has been carried out using hard-face end mill tools manufactured in accordance with the patent for the utility model (Russian Federation), which enables to improve the quality of machined surfaces by performing finishing milling in one pass and increasing equipment productivity. The determination of the roughness parameter has been carried out in accordance with the requirements of 15612 State Standard. As a result of experimental processing, the dependences of milled surface roughness on the factors under study in the form of regression equations have been obtained. The mathematical dependencies are the results of this work. It enables to set regime parameters for profile milling of MDF surface plates to obtain the required roughness. The optimal milling mode has been determined improving surface finish facade element quality of MDF case furniture.

The Processing of the Profile Surface of the Work-Pieces, Characterized by Low Rigidity

This work indicates that the prediction of the geometric indicators of the quality of the machined surface in the design of technological operations for milling a profile surface of work-pieces with low rigidity is possible, on the basis of an analysis of the elastic displacements of the technological system elements, the flexural rigidity of the work-piece as a function of its initial dimensions, the locating chart and the physical and mechanical characteristics of the material being processed. The article describes the characteristics of the elements of the technological system for the profile milling of work-pieces of low rigidity; The analytical dependencies linking the elastic displacements of the work-piece during the processing of various wood species with elements of the milling mode and the design parameters of the mill are given. Extreme total elastic displacements of the technological system during the cutting process are determined. Mathematical models of the maximum geometric error of the machined surface, as a function of the work-piece's flexural rigidity and the spindle unit, are established. Based on the results of the analysis, recommendations for improving the accuracy of the product were developed.

Adaptation of the Methodology of Designing Cylindrical Milling Processes to the Profile Milling Processes

The processes of cylindrical and profile milling of wood are considered, it is noted that when designing the technological operations of cylindrical milling, a large theoretical and experimental backlog created by scientists and specialists of woodworking complex enterprises is used. At the same time, profile milling of wood does not have such a knowledge base as cylindrical, it needs an effective technique for designing technology, equipment, cutting tools and automation tools for processing and control processes. It is proposed to use the accumulated knowledge and experience in the field of cylindrical milling in the development of equipment and technology for profile milling of wood, for which an analytical model of the correction coefficient for profile milling was developed and experiments were conducted to justify its adequacy. With the use of high-speed photography, we studied the removal of stocks for cylindrical and profile milling of wood, which resulted in a more significant dispersion of chips in the process of shaped milling, which is reflected in an increase in the power consumption of milling. The use of a correction factor for profile milling allows using the knowledge base created by predecessors in the field of woodworking and adapting a well-known technique to the processes of profile milling of stemwood and large sawmilling wastes.

Geometrical Errors of Surfaces Milled with Convex and Concave Profile Tools

The geometrical interpretation of the transformation of cylindrical milling of products into profile milling by shaping cutters with a convex and concave cutting profile is considered. A mathematical model of geometric errors of profile surfaces processed with tools with the specified cutting profiles is developed. On the basis of the model and the results of its analysis, scientifically based recommendations for designing a technological operation for profile milling of products have been developed. When processing a product with a contoured cutter with a concave profile, it is recommended to calculate the geometric errors formed in the transverse plane of the shaping cutter, and when machining with a shaping cutter with a convex cutting profile - in the planes of both its ends. The calculated values of the above geometric errors should be compared with the values limited by the work drawing of the product. The implementation of these recommendations will reduce the labor costs for experimental research and control operations associated with ensuring a given geometric accuracy of products.

Research and Evaluation on NC Programming and Simulation Based on Keller SYMplus CNC

Keller SYMplus CNC which is developed by Germany’s Keller company is a software which used for NC programming and simulation. This paper described and analyzed the characteristics of Keller SYMplus CNC software in NC programming and simulation from four aspects, model design, rapid manufacturing, machining simulation and post processing. Then compares Keller SYMplus CNC with commonly used NC programming and simulation software UG, MasterCAM, and CAXA from the profile milling and teaching function.

The schemes analysis of profile milling of long and non-technological workpieces

The article considers alternative schemes of profile milling of long non-technological workpieces – of the peripheral segments, formed during longitudinal opening of logs. Peripheral segments are a large waste of manufacture and contain the wood fibres with high physics-mechanical and operational properties. Therefore manufacturing qualitative wood products from peripheral segments is especially actual problem. However, the named workpieces are characterised by low adaptability to manufacture, therefore working out and the analysis of the machining schemes, expelling a resonance in technological system are necessary. The non-resonance machining scheme is used in a design of the milling machine tool PFP-100 for profile milling of a large wood waste.

The Effect of Cutting Fluids and Cutting Speeds to The Vibrations of Milling CNC Machine

Vibration that occur in machining process is forced vibration. This vibration caused by external force excitation. External force that cause vibration in machining process is cutting force. This research was aims to determine the effect of cutting fluids and cutting speeds to vibration in milling process. The specimens were made using a cutting process type face milling, profile milling, pocket milling, and slot milling. Cutting speeds was variated at 62.83 m/min; 110 m/min; 157.14 m/min; 188.5 m/min. Vibration testing was done using the accelerometer sensor. Vibration response taken is the amplitude. The results show any type of cutting process has a different amplitude. Face milling has the smallest amplitude while slot milling has the biggest one. At cutting speeds parameter, the faster of cutting speeds the smaller of the amplitude. The use of cutting fluids can reduce the friction value between cutting tool and workpiece so that the cutting force will decrease. The use of cutting fluids causing the smaller the cutting force. The increase of the cutting force will cause greater vibration

Limiting Product Surface and its Use in Profile Milling Design Operations

The article establishes the analytical relationships linking the geometric parameters of the shaping cutters. A mathematical model describing the geometrical errors caused by the discrete process of product profile milling with shaping cutters was developed. It was specified based on the model that the distribution of errors on the surface treated with cylindrical and shaping cutters is significantly different. It is found that the errors due to the kinematics of the cylindrical milling process, are constant at value irrespectively of the considered cross section of the cutting tooth, and the errors after the milling significantly differ in the distance function of considered transverse plane from its geometric center. The maximum error occurs in the local longitudinal planes of the product, the profile of which is located at the maximum distance from the mounting technological base of product's surface. The plane of the product, where the maximum geometrical errors are formed during the profile milling is called limiting surface. The design of technological process is performed in the product profile geometry, formed in this plane. The rule of spacious arrangement location of the limiting surface of the product according to its drawing. Using the limiting surface in the design of the operation of profile milling with shaping cutters significantly reduces the duration of the design procedure and eliminates the cost of production on experimental studies related to ensuring the geometric accuracy of products at the initial stage of their production.

Determining Undeformed Chip Thickness Models in Milling and its Verification during Wood Processing

This paper presents a mathematical model of the maximum thickness and the chip area for the processes of cylindrical and profile milling of various materials, including wood. The analytical dependences connecting the geometry of the shear layer with the elements of the milling mode and cutter design parameters are determined. Also, a model of the volume of material removed from the surface of the workpiece during the milling profile is presented. The comparative calculations of the previously known models and the models developed by the author were done. It was found that the models of the geometric parameters of cutting layer presented in the article are adequate and can be used to calculate the energy performance of the wood milling process with cylindrical and shaping cutters. These models are suitable for use in the calculations of the processing parameters for a wide range of material: metals, wood, plastic, glass and others.

Dynamics of Stock Removal in Profile Milling Process by Shaped Tool

The article describes the mechanism of the stock removal during the milling of cylindrical and shaping cutters, the cutting of the latter is outlined around. It is shown that during the processing with concaved shaping cutter the contact angle of the cutter with the workpiece changes in the height of the tool because of curved cutting teeth. The current contact angle increases from the end to the transverse mirror plane of the cutter, causing the shift in end of operation time of elementary cutting blades, considered in small neighbourhood of diametral plane of tool. It is found that for the convex surface to be treated a minimum value of the current contact angle is typical for the surface of each cutter and the maximum value - for the transverse diametral plane of the cutter. The results obtained reveal the dynamics of the stock removal in the profile milling of shaping cutter and are necessary for high-quality project of efficient processes for profile milling of mechanical engineering products, wood working and other industries. When the counter circuit of profile milling with the cutter tool the contacting of the tool with a workpiece starts at zero point of cut layer thickness and ends its maximum value at the end of a single cut which causes an increase in the cutting force.

Multidimensional Model of Surface Waviness Treated by Shaping Cutter

The article observes the regression model of waviness of the treated profile surface resulting from the planning and implementation of multidimensional experiment. The analytical dependences linking waviness of the treated surface with elements of the profile milling mode and design parameters of the shaping cutting tool were determined. Based on multidimensional model managing of the profile milling process in order to achieve the desired waviness of the treated surfaces at the highest possible performance of technological operations is performed. It was found that the dominant factors of the process of the profile milling with shaping cutter are the feed, the rate speed, the number of teeth of the cutting tool and the cutting depth. As a result of statistical processing of the experimental data was obtained the multidimensional models, the 3D XYZ surface graphics, 2D contour graphics.

Correlation between mechanical scales and analysis scales of topographic signals under milling process of natural fibre composites

This article aims to find the relation between the multiscale mechanical structure of natural fibre reinforced plastic composites and the analysis scales in the topographic signals of machined surfaces as induced by profile milling process. Bamboo, sisal and miscanthus fibres reinforced polypropylene composites were considered in this study. The multiscale process signature of natural fibre reinforced plastic machined surfaces based on wavelet decomposition was determined. Then, the impact of wavelet function was inspected by testing different wavelet shapes. Finally, the analysis of variance was carried out to exhibit the contribution rate of fibre stiffness and tool feed on the machined surface roughness at each analysis scale. Results demonstrate that studying the machining of natural fibre reinforced plastic requires the selection of the relevant scales. They show also the insignificance of the wavelet choice. This study proves that the contribution rate of fibre stiffness and tool feed on machined surface roughness is significantly dependent on the analysis scales, which are directly related to the mechanical properties of natural fibres structure inside the composite.

Mechanical Treatment of Raw Waste Lumber an Effective Way to Preserve the Ecology and Resources

Alternative process flowsheet machining of the machining of raw waste lumber were analysed, and it was implemented in a real machine model based on the chosen scheme. The forming process of the treated surface of the stock material was examined, and consequently the mathematical models of the geometric errors in terms of independent factors of the profile milling process were defined. Based on these models is possible to construct a treatment process of the raw waste lumber with minimal errors on the surfaces which were treated. The manufacturing of products from raw waste lumber allows to reduce the volume of deforestation and helps to preserve the ecology and economize the material resources.

Influence of Cutting Conditions on Profile Milling of INCONEL 738LC Alloy

This article presents particular results from a long term research focused on machining of INCONEL alloys. As a representative of this group of material INCONEL 738LC is selected and the article presents results of different experiments conducted. The behavior of material under different conditions was evaluated with focus to define cutting condition that can be recommended as suitable cutting conditions for profile milling of material. Basic problems of profile milling are exposed with focus to the respective material. Several machining experiments are explained and archived results are discussed. Effect of tool geometry and geometrical constraints and relations during profile milling is defined. Tool wear and cutting forces were measured and evaluated. The final conclusion is a recommendation for successful machining of given material.