On a Novel Tool Life Relation for Precision Cutting Tools

2005 ◽  
Vol 127 (2) ◽  
pp. 328-332 ◽  
Author(s):  
A. G. Mamalis ◽  
J. Kundra´k ◽  
M. Horva´th

When using new, very expensive superhard tool materials (diamond or CBN) for precision and ultraprecision machining of parts made, very often, from expensive materials, exact knowledge of the tool wear process (considering, of-course, its stochastic character) is absolutely necessary. It means, that we need new tool-life equations for these new tools. In the present paper, a new tool life relation is proposed based on machining experiments. It reflects the two-extremum form of tool life curves and is valid for a wide range of cutting conditions.

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Jarosław Mikuła ◽  
Daniel Pakuła ◽  
Ludwina Żukowska ◽  
Klaudiusz Gołombek ◽  
Antonín Kříž

The article includes research results for the functional properties achieved for a wide range of sintered tool materials, including sintered carbides, cermets and three types of Al2O3 oxide tool ceramics ((Al2O3 + ZrO2, Al2O3 + TiC and Al2O3 + SiC(w)) with (Ti,Al)N coating deposited in the cathodic arc evaporation (CAE-PVD) method and comparison with uncoated tool materials. For all coated samples, a uniform wear pattern on tool shank was observed during metallographic analysis. Based on the scanning electron microscope (SEM) metallographic analysis, it was found that the most common types of tribological defects identified in tested materials are: mechanical defects and abrasive wear of the tool side, crater formation on the tool face, cracks on the tool side, chipping on the cutting edge and built-up edge from chip fragments. Deposition of (Ti,Al)N coating on all tested substrates increases the wear resistance and also limits the exceeding of critical levels of permanent stresses. It even increases the tool life many times over. Such a significant increase in tool life results, among other things, from a large increase in microhardness of PVD coated materials compared to uncoated samples, increased resistance to thermal and chemical abrasion, improved chip formation and removal process conditions. Use of hard coatings applied to sintered tool materials is considered to be one of the most important achievements in improving the functional properties of cutting tools and can still be developed by improving the coating structure solutions (sorted and nanocrystalline structures) and extending the range of coating applications (Ti,Al)N in a variety of substrates.


2013 ◽  
Vol 763 ◽  
pp. 51-64
Author(s):  
Mohammed Nouari ◽  
Hamid Makich

To understand the effect of the workpiece microstructure on the tool wear behavior, anexperimental investigation was conducted on machining two different microstructures of supertitanium alloys: Ti-6Al-4V and Ti-555. The analysis of tool-chip interface parameters such asfriction, heat flux and temperature rise and the evolution of the workpiece microstructure underdifferent cutting conditions have been discussed. As cutting speed and feed rate increase, the meancutting forces and temperature show different progressions depending on the consideredmicrostructure. Results show that wear modes for cutting tools used in machining the Ti-555 alloyshow contrast from those exhibited by tools used in machining the Ti6AI4V alloy. In fact, onlyabrasion wear was observed for cutting tools in the case of machining the near-β titanium Ti-555alloy. The last alloy is characterized by a fine-sized microstructure (order of 1 μm). For the usualTi6Al4V alloy, adhesion and diffusion modes followed by coating delamination process on the toolsubstrate have been clearly identified. Moreover, a deformed layer was observed under secondaryelectron microscope (SEM) from the sub-surface of the chip with β-grains orientation along thechip flow direction. The analysis of the microstructure confirms the intense deformation of themachined surface and shows a texture modification, without phase transformation. For the Ti-555β-alloy, β grains experiences more plastic deformation and increases the microhardness of theworkpiece inducing then an abrasion wear process for cemented carbide tools. For the Ti6Al4Vmicrostructure, the temperature rise induces a thermal softening process of the workpiece andgenerates adhesive wear modes for cutting tools. The observed worn tool surfaces confirm theeffect of the microstructure on tool wear under different cutting conditions for the two studiedtitanium alloys.


2014 ◽  
Vol 1036 ◽  
pp. 405-410 ◽  
Author(s):  
Alexander Mikhaylov ◽  
Elena Sydorova ◽  
Ilya Navka

The use of cutting fluids in turning can change thermomechanical loading of cutting tools. Currently, manufacturers provide a wide range of cutting fluids, which have different combinations of lubricating and cooling properties. Depending on cutting conditions, this combination can reduce tool wear in different degrees, and, in some cases, to even increase it. Therefore, an effective choice of cutting fluids requires a considerable amount of experiments, which requires cost and time. To solve this problem in the software SIMULIA/Abaqus Explicit 6.10 was developed thermomechanical model of the turning process by cutting tools with PVD-coating, which allows simulating the effect of any combination of cooling and lubricating action. An Arbitrary Lagrangian-Eulerian formulation method was used in the modeling. Under the lubricating and cooling action is understood the final result of interaction of cutting fluids with the cutting zone. Modeling of lubricating action of cutting fluid is performed by introducing into the model corresponding average coefficient of friction in the contact zone of cutting tool, worked material and cutting fluid. Modeling of cooling action of cutting fluids is implemented through the introduction of the heat transfer coefficient, calculated on the basis of cutting conditions and thermo-physical properties of cutting fluids. As an example, turning of austenitic stainless steel X10CrNiTi18 by carbide cutting insert with TiN-coating for a predetermined cutting condition was examined. A selection of cutting fluids of the proposed range, formulations of which have different combinations of cooling and lubricating properties ("Unizor-M", "Ferrobetol-M", "EkoEM-1", "STARCUT E9", "SAFECUT M120") was accomplished through the simulation model and the calculated data contact stresses. Experimental studies have confirmed the validity of this choice by comparing the rate of flank tool wear in the using different cutting fluids. The rate of wear was determined by surface micrographs of flank tool. An application of the recommended cutting fluid "SAFECUT M120" has reduced wear by 4 times as compared with the application of the "Ferrobetol-M", the use of which has shown the highest wear. The model developed can be used for selecting a predetermined range of cutting fluids, in determining the optimal combination of lubricating and cooling actions for establishing the required characteristics of cutting fluid or in developing new formulations of cutting fluids.


Tribologia ◽  
2018 ◽  
Vol 277 (1) ◽  
pp. 7-10
Author(s):  
Vyacheslav F. BEZYAZYCHNY ◽  
Marian SZCZEREK ◽  
V.V. NEPOMILUEV ◽  
Z.W. KISELEV

The paper highlights the methods to define wear intensity of cutting tools using the theory of similarity. The dimensionless numbers of the cutting procedures, which are necessary in calculating cutting tool wear intensity, are defined with regard to the cutting conditions, cutting tool geometry, and the physico-mechanical properties of the work stock and the tool materials.


1979 ◽  
Vol 101 (2) ◽  
pp. 109-115 ◽  
Author(s):  
M. M. Tseng ◽  
R. A. Noujaim

More than three hundred flank wear profiles of carbide cutting tools were digitized, stored and analyzed. It was found that different measures of the same wear zone, such as averages or maximums including or excluding the grooves, can significantly change the out-come of tool life studies. For a given test, all the measures used in this study correlate strongly with the true overall wear average during the entire tool life. However, no conversion factor independent of cutting conditions could be found for these measures. Propagation of tool wear profiles was also analyzed. It revealed that aside from the groove zones, the entire flank face shows equal significance in describing tool wear. Thus, when a wear sensor is physically embedded on the flank face for adaptive control purposes, any location between the grooves is as good as any other.


Tribology ◽  
2005 ◽  
Author(s):  
Alexander Bardetsky ◽  
Helmi Attia ◽  
Mohamed Elbestawi

Experimental study has been carried out to establish the effect of cutting conditions (speed, feed, and depth of cut) on the cutting forces and time variation of carbide tool wear data in high-speed machining (face milling) of Al-Si cast alloys that are commonly used in the automotive industry. The experimental setup and force measurement system are described. The test results are used to calibrate and validate the fracture mechanics-based tool wear model developed in Part 1 of this work. The model calibration is conducted for two combinations of cutting speed and a feed rate, which represent a lower and upper limit of the range of cutting conditions. The calibrated model is then validated for a wide range of cutting conditions. This validation is performed by comparing the experimental tool wear data with the tool wear predicted by calibrated cutting tool wear model. The prediction errors were found to be less then 7%, demonstrating the accuracy of the object oriented finite element (OOFE) modeling of the crack propagation process in the cobalt binder. It also demonstrates its capability in capturing the physics of the wear process. This is attributed to the fact that the OOF model incorporates the real microstructure of the tool material.


2018 ◽  
Author(s):  
Kai Guo ◽  
Bin Yang ◽  
Jie Sun ◽  
Vinothkumar Sivalingam

Titanium alloys are widely utilized in aerospace thanks to their excellent combination of high-specific strength, fracture, corrosion resistance characteristics, etc. However, titanium alloys are difficult-to-machine materials. Tool wear is thus of great importance to understand and quantitatively predict tool life. In this study, the wear of coated carbide tool in milling Ti-6Al-4V alloy was assessed by characterization of the worn tool cutting edge. Furthermore, a tool wear model for end milling cutter is established with considering the joint effect of cutting speed and feed rate for characterizing tool wear process and predicting tool wear. Based on the proposed tool wear model equivalent tool life is put forward to evaluate cutting tool life under different cutting conditions. The modelling process of tool wear is given and discussed according to the specific conditions. Experimental work and validation are performed for coated carbide tool milling Ti-6Al-4V alloy.


Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 447 ◽  
Author(s):  
Sergey Grigoriev ◽  
Alexey Vereschaka ◽  
Alexander Metel ◽  
Nikolay Sitnikov ◽  
Filipp Milovich ◽  
...  

This paper deals with the Cr-CrN-(Cr0.35Ti0.40Al0.25)N coating. It has a three-layered architecture with a nano-structured wear-resistant layer. The studies involved the investigation into the microstructure (with the use of SEM and TEM), elemental and phase composition (XRD and SAED patterns), wear process pattern in scratch testing, crystal structure, as well as the microhardness of the coating. Cutting tests of tools with the above coating were carried out in dry turning of steel 1045 at cutting speeds of vc = 200, 250, and 300 m·min−1. The comparison included uncoated tools and tools with the commercial TiN and (Ti,Al)N coatings with the same thickness. The tool with the Cr-CrN-(Cr0.35Ti0.40Al0.25)N coating showed the longest tool life at all the cutting speeds under consideration. Meanwhile, a tool with the coating under study can be recommended for use in turning constructional steel at the cutting speed of vc = 250 m·min−1. At this cutting speed, a tool shows the combination of a rather long tool life and balanced wear process, without any threat of catastrophic wear.


2010 ◽  
Vol 33 ◽  
pp. 173-176
Author(s):  
X.Y. Wang ◽  
S.Q. Pang ◽  
Q.X. Yu

The aim of this work is to investigate the machinability of new coated carbide cutting tools that are named C7 plus coatings under turning of superalloy GH2132. This achieved by analysis of tool life at different cutting conditions .Investigations of tool wear and tool life testing are intended to establish T-V formulas, and then analyzed the characteristics of coating . Through a series of comparative tests, Using TiAlN coatings as the contrast materialthe results show that the new coating tools that are named C7 plus coatings are suitable for cutting superalloy GH2132. The cutting speed and processing efficiency can be increased effectively.


2012 ◽  
Vol 201-202 ◽  
pp. 1178-1181
Author(s):  
Guo Bing Chai ◽  
Wei Wang ◽  
Ai Bing Yu

Edge preparation is not only the process of grinding proper geometry of cutting edge or removing micro-cracks on cutting edge region, but also a way of improving cutting tool life. In this study, cutting models with different cutting edge radius were set up with FEM software. Medium carbon steel cutting tests were carried out using cutting tools with different edge radius. Cutting tool wear was simulated and measured for comparison. The simulation results show that edge radius has influences on tool wear. Tool cutting behavior is concerned with edge radius. A proper edge radius will improve the tool life. The experimental results show that proper edge preparation could improve tool impact resistance capability and reduce tool wear. The cutting tool life can be prolonged with suitable edge preparation. Edge preparation can improve cutting performance of cutting tool.


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