Tool Cutting Edge Angle Research Articles

Semi-Empirical Prediction of Turned Surface Residual Stress for Inconel 718 Grounded in Experiments and Finite Element Simulations.

The surface residual stress after machining, especially for finishing, has a vital influence on the shape stability and fatigue life of components. The current study focuses on proposing an original empirical equation to predict turned surface residual stress for Inconel 718 material, taking tool parameters into consideration. The tool cutting-edge angle, rake angle, and inclination angle are introduced for the first time in the equation based on the Inconel 718 material turning experiments and finite element simulations. In this study, the reliability of simulation parameters’ setting is firstly calibrated by comparing the residual stresses and chips of the experiments and simulations. The changing trends of turned forces, temperatures of lathe tool nose, and surface residual stress with turning parameters are analyzed. Then, the predictive equation of surface residual stress is proposed considering relationships between the back-rake angle, the side-rake angle, and the tool cutting-edge angle, rake angle, and inclination angle. Moreover, the genetic algorithm optimizes the objective function to obtain the undetermined coefficients in the prediction equation. Finally, the predicted accuracy of the surface residual stress is proven by comparing the experimental, simulation, and prediction values. The results indicate that the predictive equation of surface residual stress has a good accuracy in predicting turned surface residual stress for Inconel 718 materials. The correlation coefficient, R, and absolute average error between the predicted and the simulated value are 0.9624 and 13.40%, respectively. In the range of cutting parameters studied and experimental errors, this study provides an accurate predictive equation of turned surface residual stress for Inconel 718 materials.

Deformation-induced martensitic transformation in AISI304 by cryogenic machining

In order to substitute a heat treatment to obtain a hardened subsurface, cryogenic machining can be used if the steels machined contain metastable austenite. To exploit the martensitic transformation, the mechanism of the deformation-induced martensitic transformation upon machining needs to be known. It was found that by lowering the machining temperature a martensitic transformation can be achieved in grains independent of the Schmid factor for a temperature of −196 °C. At higher temperatures, grains in preferred direction with higher Schmid factor tend to transform into martensite. Therefore, it is concluded that the temperature should be either low enough to achieve a sufficient martensitic transformation, or beforehand a texture could be produced prior to the machining process. Another possibility is to add a second machining step with a different tool cutting edge angle to activate the transformation in other grains.

Determination of Ideal Cutting Conditions for Maximum Surface Quality and Minimum Power Consumption During Hard Turning of AISI 4140 Steel Using TOPSIS Method Based on Fuzzy Distance

In this study, hard turning tests are carried out on the hardened AISI 4140 steel material. Power consumption, sound intensity, processing time and surface roughness values are measured for all combinations of cutting conditions such as three different cutting speeds, three different feed rates, three different depths of cut and two different tool cutting edge angle. According to these measurements, the ideal cutting condition is found by using the TOPSIS method which is integrated by fuzzy Hamming distance, Euclidean distance and Hausdorff distance measure methods. Also in case that machinability parameters have different importance degrees, ideal cutting condition is determined by using the weighted fuzzy distance measure method. According to the experimental results obtained, it is observed that the surface roughness value increased with the increasing feed rate. Roughness values obtained at 90 degree tool cutting edge angle are lower than 62.5 degrees. It is observed that the sound intensity increases with the increasing feed rate. The machining time is reduced with increasing feed rate, depth of cut and cutting speed. Thus, total power consumption is reduced.

The Influence of Changing of Treatment Condition on Surface Roughness Parameter During Turning Process by Wiper Insert

Abstract One of the greatest problems of modern production techniques is the achievement of an appropriate quality at minimal costs and accompanied by the production efficiency increase. Therefore, while designing the production process. The technology used should have a considerable influence on the durability and reliability of machine parts to be produced. During finish treatment, the final dimensions as well as functional properties are imparted to a given element by application of proper treatment type. The engineer has a range of production techniques to choose for the proper surface layer formation. It is crucial to find a suitable solution which will meet the requirements as well as the work conditions of a given machine part. The article presents the results of influence of change of cutting parameters on surface roughness parameter during turning process of stainless steel. A shaft made of 304L stainless steel was used for the research. The chemical composition of steel was measured by Solaris-ccd plus optical spectrometer. The cutting process was carried out on a universal CDS 6250 BX-1000 centre lathes. Measurement of surface roughness was carried out by T8000 profilometer. The turning process was conducted by a cutting tool with Wiper insert. During the turning, the following machining parameters were used: cutting speed Vc [m/min], feed f [mm/rev], cutting depth ap [mm] and additionally changed nose radius r [mm], and tool cutting edge angle ᵪr [°]. The results of measurements of Ra parameter underwent statistic analysis. The calculations were conducted by Statistica software.

Study of Surface Roughness and Burr Formation After Milling of Carbon Fiber/Titanium Stacks

This work aims to study the influence of cutting parameters (cutting speed, feed rate, cutting depth and tool cutting edge angle) regarding surface roughness and burr formation during the milling of a mixed structure comprised of titanium and carbon fiber (stack). The parameters were varied from maximum to minimum, just as the tool cutting edge angle of the insert, through a full factorial design with 32 trials. The analyses were performed by measuring the surface roughness and burr size along with metallographic analyses through optic microscopy and scanning electron microscopy. The results showed that the surface roughness was higher for carbon fiber and burr size was higher for titanium. There were a number of tests with delamination of the carbon fiber, and the best cutting parameters to minimize surface roughness and burr formation were tool cutting edge angle of 45º, a feed rate of 0.028 mm/tooth, cutting depth equal to 0.26 mm and cutting speed equal to 150 m/min.

A geometrical investigation the effect of volumetric chip expansion factor in orthogonal turning processes

Chip morphology is the remnant of the machining processes, providing to examine the quality of the machinability. The shape of the chip and its deformation rate identifying the severe of the processes outcomes like surface quality, tool life, required cutting forces and power. Especially plastic deformation in primary deformation zone makes the volume of the chip increase. The shear angle (φ), tool cutting edge approach angle (χ), and chip thickness (t) are the most influential parameters on the volumetric chip expansion factor (r1) in primary deformation zone. While tool cutting edge angle (χ) has a correlate proportional effect, shear angle (φ) and chip thickness (t) inversely proportional effect, on the volumetric chip expansion factor. According to getting the optimum volumetric chip expansion factor (r1), the lower tool cutting edge angle and feed rates, but higher shear angle must be selected. Rake angle (α) and cutting depth (a) have not remarkable effect on the volumetric chip expansion factor (r1), but rake angle only provides the sliding of the chip on the tool rake face.

About the influence of λ tool cutting edge angle on its bevelled metal cutting power

About the influence of λ tool cutting edge angle on its bevelled metal cutting power

Prediction model and simulation of cutting force in turning hard-brittle materials

The removal mechanism of hard-brittle material was studied in this paper. The shear strain and specific shear work of brittle material cutting were analyzed. The cutting force model of hard-brittle material was developed based on the fracture mechanics. Johnson-Cook model was modified and applied to finite element simulation of hard-brittle material cutting. The cutting force of machinable ceramics was predicted by BP neural network. The turning experiments of machinable ceramics were carried out. The influence of processing parameters on cutting force was investigated. The results show that the modified constitutive model well reflects the fracture removal process of brittle material. The simulation results are in well agreement with experimental data and theoretical data. The effects of cutting depth and feed speed on cutting force are larger than those of cutting speed and tool cutting edge angle.

Повышение качества поверхности при обработке волоконно-армированного композита фрезой с встречно расположенными лезвиями на основе sph моделирования

Unidirectional fiber-reinforced composite workpieces are often machined in practice. During such cutting process stronger fibers are bended more than weaker matrix and an interfacial debonding between them is occurred under machined surface. It deteriorates working properties of composite and so debonding reduction is a vital technological problem. One of the perspective ways to diminish such debonding is to substitute the orthogonal cutting by the oblique one. This decision is confirmed by known practice of milling cutter design. Milling cutters with the continuous helix edges and with interrupted ones with a large tool cutting edge angle are often used. In this case fiber deformations in a cutting zone are significant. To diminish such deformations the hypothesis about efficient use of opposite cutting edges location with a large tool cutting edge inclination is assumed. This hypothesis is checked by using of SPH method with micro-simulation of cutting of metal-matrix composites (steel fibers and aluminum alloy matrix). Johnson-Cook approach is used for both materials. Obtained qualitative deformation pictures confirm this hypothesis. On this basis a new milling cutter design with tool major cutting edges located as a chevron on a cylindrical surface with alternate arrangement is suggested. Computer simulation of such edges operation shows minimal fibers deformations in cutting zone. At the same time, undesired excessive chip packing in a zone between the adjacent cutting edges is not observed. The obtained results are preliminary considering the limited computer model size and no experiment verification made.

Experimental study of the combined influence of the tool geometry parameters on the cutting forces and tool vibrations

The aim of the experimental investigations was to select the optimal proposed cutting tool geometry by studying the effects of the tool angles (tool back rake angle (γ p )) and the cutting edge angles (the tool cutting edge angle of the major cutting edge (κ r ) and cutting edge inclination angle (λ s )) and there interrelations, which produces less-generated cutting forces, less tool vibrations, and improved machined surface roughness for turning operations. Different cutting tool geometries were designed according to the main tool angles and manufactured with a high speed steel material (HSS) type-T15 with a high tungsten alloy grade. Based on measured cutting force components, tool vibrations, and surface roughness, it can be concluded that when the γ p angle ranges from a negative value (γ p = −5°) to a positive value (γ p = 0° and γ p = 5°), the average cutting force components decreased, especially tangential force component (Fz) that was more remarkable, and tool vibrations reduced; this decreasing trend improved surface roughness. The effects of the variation of the κ r angle and the positive λ s angle were observed on the variation of the axial and radial force component, whereas the tangential force remained constant. Lowering κ r decreased the surface roughness, while the λ s angle increased, a small variation was observed. As a conclusion, the good optimized cutting tool geometries were classified as follows: the first was cutting tool geometry having a neutral angle (γ p = 0°), the second was with γ p = +5°, and then the third was with γ p = −5°. Thereafter, the fourth tool geometry was having λ s = 3° and the last was for geometry having κ r = 75°.

Experimental study and genetic algorithm-based optimization of cutting parameters in cutting engineering ceramics

The paper aimed at conducting cutting experiments on engineering ceramics and investigating the influence of machining process input parameters such as cutting depth, feed speed, and tool cutting edge angle on the output parameters such as materials removal rate and cutting tool wear rate. The regression equations were then solved using the least squares fitting method and the relationships between material removal rate and input parameters as well as between cutting tool wear rate and input parameters were obtained. Genetic algorithm was available for optimizing the input parameters to get output parameters. Therefore, the optimum combinations of input parameters for maximum material removal rate and minimum cutting tool wear rate were found.

Analytical modeling and experimental investigation of ultrasonic-vibration assisted oblique turning, part III: Experimental investigation

The experimental investigation of the kinematics and dynamics of ultrasonic-vibration assisted oblique turning (oblique UAT) has been undertaken in the present study. For the purpose of comparison, the conventional oblique turning experiments were also carried out in parallel to the oblique UAT experiments. The burnishing effect of the vibrating motion of the cutting tool has been studied as a means of illustrating the kinematic interaction between the cutting tool and the workpiece in vibration cutting. The experimental investigation of the influence of oblique UAT parameters on the dynamics of the process has been another subject of the present study. The oblique UAT parameters taken into consideration consisted of vibration amplitude, cutting speed, inclination angle, tool cutting edge angle and feed rate. The cutting force components were differently influenced by these parameters. The inclination angle, tool cutting edge angle and feed rate did not have any significant effect on the cutting force ratio whereas the cutting speed and the vibration amplitude highly influenced this ratio. The experiments were carried out with aluminium 6061 and 2024.

Analytical modeling and experimental investigation of ultrasonic-vibration assisted oblique turning, part II: Dynamics analysis

In the present study, a theoretical model has been developed for the analysis of the dynamics of ultrasonic-vibration assisted oblique turning. Various parameters including inclination angle, normal rake angle, tool cutting edge angle, cutting velocity, feed rate, vibration frequency and amplitude were taken into consideration in addition to other dynamics parameters such as inertial effect. The thin shear plane theory was used for the analysis. The time dependent and average cutting forces could be estimated and compared with the cutting forces in conventional turning.

Study on Machinery Cutting Technology of Ceramic Parts

The machinability of ceramics is evaluated by data envelopment analysis, mathematical programming model is constructed, then the optimal solution of decision-making unit is found. These reference values of he tool rake angle, clearance angle, tool cutting edge angle, minor cutting edge angle, tool cutting edge inclination angle, tip ARC radius and cutting speed, back engagement and the range of feeds are obtained through by orthogonal cutting test, these processing parameters are optimized, then better processing results are achieved. Considering the problem of Machining of ceramic materials, the techniques of mechanical cutting process, ceramic turning, grinding, drilling, et al are discussed.

Edge Design for Regrinding Cutting Tool

Regrinding of wasted cutting tools can recycle resources and decrease manufacturing costs. Influence of relative tool sharpness and tool cutting edge angle on tool edge radius were analyzed. Cutting force and cutting temperature were simulated with FEM on different edge radius. Edge preparation experiments were carried out though an abrasive nylon brushing method. The results show that RTS and cutting edge angle have influence on edge radius. Small edge radius might result in small cutting forces and lower average temperatures, could maintain the cutting state between tool and workpiece. The cutting edge defects can be eliminated through edge preparation, and a smooth cutting edge can be obtained. Cutting tool life will be improved through proper edge design and edge preparation.

The assessment of plastic deformation in metal cutting

Because plastic deformation is a nuisance in the metal cutting process, its proper account is of high interest. A new meaning for the chip compression ratio is discussed showing that, on the contrary to shear strain, this parameter represents the true plastic deformation in metal cutting. The chip compression ratio can be used to calculate the total work done by the external force applied to the tool and then might be used for optimization of the cutting process. It is demonstrated that the cutting speed influences the energy spent on the deformation of the chip through temperature, dimensions of the deformation zone adjacent to the cutting edge and velocity of deformation. The separate impacts of these factors have been analyzed and the physical background behind the known experimental dependence of the chip compression ratio on the cutting speed is revealed. The influence of the cutting feed, tool cutting edge angle, cutting edge inclination angle and tool rake angle have also been analyzed.

Geometry of drill elements

Deficiencies in the definitions of some of the angles in the ISO on Cutting Tool Geometry have been noted and new definitions are proposed. It is shown that some of the trigonometrical relationships interrelating the various angles derived for the acute tool cutting edge angle do not apply when the tool cutting edge angle is greater than 90°, as can occur with certain cutting tools. A consistent set of relationships is presented for the total range of the cutting edge angle. Relationships are presented for the various angles on the cutting lip and chisel edge of a twist drill and the effects of radius and feed on the various parameters are shown diagrammatically.

The Use of Fundamental Mechanical Properties in the Design of the Tool Cutting Angles

In machining of the 4th group alloys (Titanium and Zirconium) as well as of refractory alloys, it seems that the tool cutting edge angle χ has an important influence on the chip's geometry and on the tool life. The study presents and verifies a relationship between the tool cutting edge angle χ and an anisotropy ratio defined from mechanical properties of the workpiece material. In its theorical part, the study presents the research of the direction with the largest instability of shearing and it also defines an angle i as tg i is equal to the square of the anisotropy ratio. In its experimental part, the study verifies that for the tool cutting edge angle χ, which is equal to χ, the chip is an elemental chip propelled away from the workpiece which represents the optimal chip for the automatised production.