The Life of Carbide-Tipped Turning Tools

1947 ◽  
Vol 157 (1) ◽  
pp. 452-469 ◽  
Author(s):  
F. F. P. Bisacre ◽  
G. H. Bisacre

The paper is a contribution towards a rational quantitative theory of the tool-life problem. In the first part of the paper, the authors discuss an adiabatic theory of high-speed metal cutting, with no coolant. In machining medium-carbon steel with dry tungsten-carbide, cutting takes place under two widely different physical conditions, depending on the speed of cutting. Plastic deformation of the metal takes place as the chip crosses the tool face, and a higher temperature is developed most intensely at or near the surface of the cutting in contact with the tool face. Consequently the temperatures generated are higher—perhaps much higher—in the lower layers of the chip than elsewhere. If the speed of cutting is high, there is not sufficient time for effective diffusion of heat to take place into the colder parts of the cutting; the heat in fact stays where it is generated. The conditions are adiabatic. On the other hand, when cutting is slow enough, there is time for complete diffusion of heat to take place, whereby the temperature becomes uniform through the thickness of the chip. This is the isothermal case. It is found that these extremes occur when Reynolds thermal number (speed × thickness of chip ÷ thermal diffusivity) is large or small, respectively. In the second part of the paper, a series of experiments made by M. F. Judkins and W. E. Uecker in 1933 on tool life is examined, and a rule is given that embodies the results of these tests with unexpected accuracy. In the third and last part of the paper, a study is made of those properties of the metal cut and of the tool that affect the life of the tool. The method of dimensional analysis is applied to deduce a general form for the life-law. Judkins and Uecker's experimental result conforms to this law within the limits of the tests. But further experiment alone can confirm the general form—in its wider application.

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.


2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nurul Hayati Binti Abdul Halim ◽  
Che Hassan Che Haron ◽  
Jaharah A. Ghani ◽  
Muammar Faiq Azhar

Purpose The purpose of this study is to present the tool life optimization of carbide-coated ball nose milling inserts when high-speed milling of Inconel 718 under cryogenic CO2 condition. The main aims are to analyze the influence level of each cutting parameter on the tool life and to identify the optimum parameters that can lengthen the tool life to the maximum. Design/methodology/approach The experimental layout was designed using Box–Behnken RSM where all parameters were arranged without combining their highest and lowest values of each factor at the same time. A total of 29 milling experiments were conducted. Then, a statistical analysis using ANOVA was conducted to identify the relationship between the controlled factors on tool life. After that, a predictive model was developed to predict the variation of tool life within the predetermined parameters. Findings Results from the experimental found that the longest tool life of 22.77 min was achieved at Vc: 120 m/min, fz: 0.2 mm/tooth, ap: 0.5 mm and ae: 0.2 mm. ANOVA suggests the tool life of 23.4 min can be reached at Vc: 120.06 m/min, fz: 0.15 mm/tooth, ap: 0.66 mm and ae: 0.53 mm. All four controlled factors have influenced the tool life with the feed rate and radial depth of cut (DOC) as the major contributors. The developed mathematical model accurately represented the tool life at an average error of 8.2 per cent when compared to the actual and predicted tool life. Originality/value These experimental and statistical studies were conducted using Box–Behnken RSM method under cryogenic CO2 condition. It is a proven well-known method. However, the cooling method used in this study is a new technique and its effects on metal cutting, especially in the milling process of Inconel 718, has not yet been explored.


2009 ◽  
Vol 626-627 ◽  
pp. 189-194
Author(s):  
P. Liu ◽  
Jiu Hua Xu ◽  
Yu Can Fu

TA15 (Ti-6.5Al-2Zr-1Mo-1V) is a close alpha titanium alloy strengthened by solid solution with Al and other component. A series of experiments were carried out on normal and high speed milling of TA15. The recommended tools for many years had been the uncoated tungsten carbide grade K. In this work, the tool life of coated carbide tools used in high speed milling of forging and cast titanium alloy was studied. Additionally, the wear mechanism of cutting tools was also discussed. Finally, surface integrity, including surface roughness, metallograph and work hardening, were examined and analyzed. The result shows that the surface quality of forging and cast machined by carbide cutter is similar, but the tool life of carbide in high speed milling of forging TA15 is longer than that in high speed milling of cast TA15.


2011 ◽  
Vol 697-698 ◽  
pp. 102-106 ◽  
Author(s):  
Q. Shi ◽  
Ning He ◽  
Liang Li

In this paper, a series of experiments were carried out on normal and high speed milling of a new damage-tolerant titanium alloy. The effects of milling parameters on cutting force and cutting temperature were investigated. The tool life of three commonly used cutters, such as WK10, WMG40 and WXN15, were studied. Result shows that the tool life of cutter WXN15 was the longest one when using the same flank wear VB as a standard, and cutter WK10 had a longer too life than cutter WMG40. Thus cutter WXN15 was the most suitable cutting tool to machining TC4-DT, and cutter WK10 was better than cutter WMG40.


2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.


2020 ◽  
pp. 74-78
Author(s):  
A.E. Dreval

The assessment of the limiting state of high-speed machine-manual taps in the processing of structural steel billets is considered. A general multi-parameter dependence is developed for calculating the criterion of allowable wear, which makes it possible to rationally use the tool life and normalize the cut amount during regrinding. Keywords thread cutting, tap, angle of the cutting part, criterion, high-speed steel, wear, failure, life, service life. [email protected]


2007 ◽  
Vol 567-568 ◽  
pp. 185-188 ◽  
Author(s):  
Miroslav Piska

Modern trends in metal cutting, high speed/feed machining, dry cutting and hard cutting set more demanding characteristics for cutting tool materials. The exposed parts of the cutting edges must be protected against the severe loading conditions and wear. The most significant coatings methods for cutting tools are PVD and CVD/MTCVD today. The choice of the right substrate or the right protective coating in the specific machining operation can have serious impact on machining productivity and economy. In many cases the deposition of the cutting tool with a hard coating increases considerably its cutting performance and tool life. The coating protects the tool against abrasion, adhesion, diffusion, formation of comb cracks and other wear phenomena.


2014 ◽  
Author(s):  
Jerald E. Jones ◽  
Valerie L. Rhoades ◽  
Mark D. Mann ◽  
Todd Holverson

A new cutting process, a hybrid system, uses induction heating to heat the metal ahead of the plasma cutting torch. The process has demonstrated the ability to plasma cut steel parts at speeds of up to 4X the speed of the plasma torch without the induction heating. Although the total heat input per unit time is greater, because of the increase in speed, the heat which is conducted into the cut pieces is less. This causes less potential metallurgical damage, less potential distortion, and reduced coating damage and reduced emissions during cutting, in comparison to the plasma cutting process without the induction heating. The initial development was primarily for use in cutting nuclear submarine and aircraft carrier hulls, for scrapping after decommissioning. The process has been demonstrated cutting steel plates and can be used in ship production as well. The primary motivation of the SBIR project was to reduce the heating of the cut pieces, in order to reduce the particulate matter (PM) emissions which occur when coated ship hull material is cut. An induction coil is positioned in front of the plasma cutting torch, to bring the material to an elevated temperature of at least 1600° F, before the plasma is applied to the metal surface. Induction heating testing has shown that the 35 kW induction system can maintain the 1600° F surface temperature at travel speeds of above 220 inches per minute on steel as thick as 3 inches. Once the steel is at that temperature an air plasma torch can cut the metal much faster than cutting cold steel.


Author(s):  
Yefei Liu ◽  
Yang Liu ◽  
Xingtuan Yang ◽  
Liqiang Pan

Series of experiments are conducted in a single microchannel, where subcooled water flows upward inside a transparent and vertical microchannel. The cross section of the channel is rectangle with the hydraulic diameter of 2.8mm and the aspect ratio of 20. The working fluid is 3–15K subcooled and surface heat flux on the channel is between 0–3.64 kW/m2, among which two-phase instability at low vapor quantity may occur. By using a novel transparent heating technique and a high-speed camera, visualization results are obtained. The parameters are acquired with a National Instruments Data Acquisition card. In the experiments, long-period oscillation and short-period oscillation are observed as the primary types of instability in a microchannel. Instability characteristics represented from signals correspond well with the flow pattern. Moreover, effects of several parameters are investigated. The results indicate that the oscillating period generally increases with the heat flux density and decreases with inlet subcooling, while the effects of inlet resistance are more complex.


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