Observations on the Angle Relationships in Metal Cutting

1959 ◽  
Vol 81 (3) ◽  
pp. 263-279 ◽  
Author(s):  
D. M. Eggleston ◽  
R. Herzog ◽  
E. G. Thomsen

Orthogonal-cutting experiments using SAE 1112 free-cutting steel, 2024-T4 and 6061-T6 aluminum alloys, and alpha-brass (85 Cu-15 Zn) at feeds of 0.002 to 0.010 ipr, were performed on a lathe with 18-4-1 high-speed-steel cutting tools. The mean cutting speeds and rake angles for SAE 1112 varied from 33.7 to 170.8 fpm and 5 to 40 deg, respectively, while the remainder of the alloys were tested at conditions yielding a continuous chip without a built-up edge at speeds ranging from approximately 470 to 790 fpm. It was found that the angle λ between the shear plane and the resultant tool force R was only approximately constant for each test condition and varied with cutting speed. Hence the equation λ = ϕ + β − α = const and the linear relationship between ϕ and β − α are only approximately satisfied. Furthermore, neither the Ernst and Merchant minimum-energy criterion, nor the Lee and Shaffer nor the Hill ideal plastic-solid solution, is in agreement with all the experimental observations.

1965 ◽  
Vol 87 (4) ◽  
pp. 480-486 ◽  
Author(s):  
J. D. Cumming ◽  
S. Kobayashi ◽  
E. G. Thomsen

The mechanics of orthogonal cutting have been reexamined and for the shear-plane concept of metal cutting, linear and quadratic-force models were suggested. It was shown that for steel SAE-1213, investigated under variable cutting conditions, the dynamic shearing stress remained constant and the linear-force model correlated with those experimental data which were obtained under the absence of a BUE. The angle λ formed by the shear plane and the direction of the resultant force remained constant for each test condition but varied with cutting speed. Neither the Ernst and Merchant minimum energy, nor the Lee and Shaffer solutions are in agreement with experimental observations.


1999 ◽  
Vol 122 (4) ◽  
pp. 650-659 ◽  
Author(s):  
H. Ren ◽  
Y. Altintas

Chamfered cutting tools are used in high speed machining of hardened steels due to their wedge strength. An analytic model is proposed to investigate the influence of chamfer angle and cutting conditions on the cutting forces and temperature. The model is based on the tool geometry, cutting conditions, steady state temperature in the shear and chip-rake face contact zones, strain, strain rate, and the corresponding flow stress of the work material. With the aid of a slip line field model, the cutting and friction energy in the primary, secondary and chamfer zones are evaluated. By applying the minimum energy principle to total energy, the shear angle in the primary deformation zone is estimated. The corresponding shear strain, strain rate and flow stresses are identified. The model leads to the prediction of cutting forces and temperature produced in three deformation zones. The model is experimentally verified by high-speed orthogonal cutting tests applied to P20 mold steel using ISO S10 carbide and CBN cutting tools. It is shown that the analytic model is quite useful in selecting optimal chamfer angle and cutting speed which gives the minimum tool wear and relatively lower cutting forces. [S1087-1357(00)00204-5]


2012 ◽  
Vol 557-559 ◽  
pp. 1364-1368
Author(s):  
Yong Feng ◽  
Mu Lan Wang ◽  
Bao Sheng Wang ◽  
Jun Ming Hou

High-speed metal cutting processes can cause extremely rapid heating of the work material. Temperature on the machined surface is critical for surface integrity and the performance of a precision component. However, the temperature of a machined surface is challenging for in-situ measurement.So, the finite element(FE) method used to analyze the unique nonlinear problems during cutting process. In terms of heat-force coupled problem, the thermo-plastic FE model was proposed to predict the cutting temperature distribution using separated iterative method. Several key techniques such as material constitutive relations, tool-chip interface friction and separation and damage fracture criterion were modeled. Based on the updated Lagrange and arbitrary Lagrangian-Eulerian (ALE) method, the temperature field in high speed orthogonal cutting of carbon steel AISI-1045 were simulated. The simulated results showed good agreement with the experimental results, which validated the precision of the process simulation method. Meanwhile, the influence of the process variables such as cutting speed, cutting depth, etc. on the temperature distribution was investigated.


Author(s):  
Mitsuru Hasegawa ◽  
Tatsuya Sugihara

Abstract In cutting of Ti-6Al-4V alloy, the cutting speed is limited since a high cutting temperature leads to severe tool wear and short tool life, resulting in poor production efficiency. On the other hand, some recent literature has reported that various beneficial effects can be provided by forming micro-textures on the tool surface in the metal cutting process. In this study, in order to achieve high-performance machining of Ti-6Al-4V, we first investigated the mechanism of the tool failure process for a cemented carbide cutting tool in high-speed turning of Ti-6Al-4V. Based on the results, cutting tools with micro textured surfaces were developed under the consideration of a cutting fluid action. A series of experiments showed that the textured rake face successfully decreases the cutting temperature, resulting in a significant suppression of both crater wear and flank wear. In addition, the temperature zone where the texture tool is effective in terms of the tool life in the Ti-6Al-4V cutting was discussed.


Author(s):  
N.V. Ferdinandov ◽  
D.D. Gospodinov

Purpose: To present a technology for hardfacing of metal-cutting tools by arc welding in vacuum. Design/methodology/approach: The experiments were carried out using an installation for arc welding in vacuum. Objects of research were metal cutting tools (lathe knives), made of high-speed steel HS6-5-2 on a base metal of structural steel C45. The structure, hardness and wear resistance after hardfacing and after a triple tempering at 560°C have been determined. The heat resistance of the obtained instruments has been examined. Findings: The microstructural analysis showed that the structure of the built-up layer consisted of martensite, retained austenite and carbides. This was confirmed by the values of measured hardness after welding which were about 63-64 HRC. The triple tempering led to an increase in hardness by 3-4 HRC. It was found that the built-up layers (cutting edges of tools) retain their hardness (HRC=63-65) up to a temperature of 615-620°C, which shows that the heat resistance of the build-up layers was similar to that of the hardened and tempered tools of the same steel. The built-up work-pieces (excluding heat treated) and the reference knife showed the same cutting qualities at cutting speeds in the range of 55 to 120 m/min. It has been found that triple tempering after hardfacing led to increased wear resistance and consequently the durability of the tool also increased due to the higher hardness. Practical implications: The practical application is related to the production of metalcutting tools. Originality/value: The proposed technological method allows to produce defects free built-up layers. The cutting properties of the built-up in vacuum layers are comparable to or better than those of new tools made of steel HS 6-5-2.


2020 ◽  
Vol 10 (9) ◽  
pp. 3057
Author(s):  
Keguo Zhang ◽  
Keyi Wang ◽  
Zhanqiang Liu ◽  
Xiaodong Xu

Metal cutting speeds are getting faster with the development of high-speed cutting technology, and with the increase in cutting speed, the strain rate will become larger, which makes the study of the metal cutting process more inconvenient. At the same time, with the increase in strain rate, the dislocation movement controlling the plastic deformation mechanism of metal will change from thermal activation to a damping mechanism, which makes the metal deformation behave more like a fluid. Therefore, it is necessary to explore new ways of studying machining from the perspective of fluid flow. Based on this, a fluid model of the metal cutting process is established, and a method for calculating the strain rate is proposed from the point of view of flow. The results of the simulation and measurements are compared and analyzed. The results show that the strain rate on the rake face will be affected by the friction between the chip and tool; the nearer the distance between the chip layer and tool rake face, the bigger the strain rate will be. The strain rate in the central shear plane is much larger than in other areas along the shear plane direction, and in which two ends are the biggest. It can achieve rougher, quantitative research. This shows it is feasible to study machining from the viewpoint of fluid flow, though it still needs a lot of theoretical support and experimental confirmation.


2015 ◽  
Vol 788 ◽  
pp. 325-329
Author(s):  
Alexander G. Ovcharenko ◽  
Andrey Yu. Kozlyuk ◽  
Mikhail O. Kurepin

Abstract. A promising method for improving wear resistance of metal cutting tools including pre-heating and a subsequent impact of the pulsed magnetic field of high intensity on the cutting tool is proposed. The experimental setup and methods of research are described. Experimental studies of surfaces of carbide reversible cutting plates of the VK8, T15K6 alloy and drills of high speed steel R6M5 to assess the effectiveness of the proposed method were performed. An increase in wear resistance of cutting tools made of the T15K6 hard-alloy plates by 30% and made of the VK8 alloy plates by 13% was revealed while wear resistance of drills made of steel R6M5 increased on average by 58% The proposed method can be of practical interest for hardening the surface of other types of tools and machine parts for further experimental verification.


2015 ◽  
Vol 669 ◽  
pp. 278-285
Author(s):  
Anton Panda ◽  
Ján Duplák ◽  
Miroslav Kormoš ◽  
Slavko Jurko

Essential factors of each new discovery or piece of knowledge in science are predetermined, prepared and realized experiment. Every successfully realized experiment with obtained outputs and measurements indicates the gauge of asset that has been achieved by its execution. After analyzing of outputs final dependencies can be described that generalize whole experiment and allow entire process to be analytically identified. The production of bearings is very difficult process. Especially production of bearing rings is very complicated. Optimization of this process means significant savings for the company. Bearing rings are produced by turning. One of the most important parts of the turning process is cutting tool. On the base of cutting tools are determined many factors for example: quality, price, cutting speed, etc. All these factors of cutting tools are the only consequence of these cutting tools durability. Cutting tool durability determines its cutting properties and machinable ability. Specification of tool wear by means of calculation is very difficult. Durability of cutting tools is defined in standard ISO 3685. In standard ISO 3685 is definedT-vcdependence for different cutting materials and standard included process evaluation of tool durability for cutting materials made of high speed steel, sintered carbide and cutting ceramic. The article describes evaluation ofT-vcdependence on the selected type of cutting materials and theirs comparison with measured values T-vc dependence that are defined in standard ISO 3685.


2013 ◽  
Vol 797 ◽  
pp. 208-213 ◽  
Author(s):  
Jun Shinozuka

The orthogonal cutting tests of oxygen free copper with a cutting speed of from 1 m/s to 210 m/s were performed. The effect of the high-speed cutting on the improvement over the quality of the machined surface, which was evaluated by the thickness of the plastic flow layer and the surface roughness, was examined. By employing the simple shear plane model, the cutting mechanism was analyzed. The results were compared with the results for cutting of aluminum alloy obtained previously. For oxygen free copper, the resultant cutting force does not increase in high-speed cutting. However, the friction angle on the tool-chip interface rises clearly in high-speed cutting. This paper discusses the reason for the increase in the friction angle at the tool-chip interface by investigating the stress and temperature fields on the shear plane and the tool-chip interface.


2013 ◽  
Vol 652-654 ◽  
pp. 2218-2221 ◽  
Author(s):  
Li Bao An ◽  
Chun Guang Lu

Metal cutting indicates a specific category of processes in which unwanted material is removed from workpeice by single- or multi-point cutting tools for making products meeting prescribed specifications. Parameter optimization in metal cutting plays an important role in satisfying quality requirements of machined parts at low production cost or time. It requires optimal selection of cutting speed, feed rate, depth of cut, and the number of passes. A brief review of recent progress on the optimization of cutting parameters is introduced in the present work. Some new machining practices expending in recent years are involved including hard turning, dry cutting, high speed machining, machining of difficult-to-machine materials and composites. Modeling skills for creating optimization models and optimization techniques for solving optimal or near-optimal solutions are summarized and analyzed.


Sign in / Sign up

Export Citation Format

Share Document