Assessment of tool wear and microstructural alteration of the cutting tools in conventional and sustainable slot milling of Ti-6Al-4V alloy

2019 ◽  
Vol 105 (7-8) ◽  
pp. 2799-2814 ◽  
Author(s):  
Ashutosh Khatri ◽  
Muhammd P. Jahan ◽  
Jianfeng Ma
Keyword(s):  
Author(s):  
Niniza S. P. Dlamini ◽  
Iakovos Sigalas ◽  
Andreas Koursaris

Cutting tool wear of polycrystalline cubic boron nitride (PcBN) tools was investigated in oblique turning experiments when machining compacted graphite iron at high cutting speeds, with the intention of elucidating the failure mechanisms of the cutting tools and presenting an analysis of the chip formation process. Dry finish turning experiments were conducted in a CNC lathe at cutting speeds in the range of 500–800m/min, at a feed rate of 0.05mm/rev and depth of cut of 0.2mm. Two different tool end-of-life criteria were used: a maximum flank wear scar size of 0.3mm (flank wear failure criterion) or loss of cutting edge due to rapid crater wear to a point where the cutting tool cannot machine with an acceptable surface finish (surface finish criterion). At high cutting speeds, the cutting tools failed prior to reaching the flank wear failure criterion due to rapid crater wear on the rake face of the cutting tools. Chip analysis, using SEM, revealed shear localized chips, with adiabatic shear bands produced in the primary and secondary shear zones.


Author(s):  
Sandro Turchetta ◽  
Luca Sorrentino ◽  
Gianluca Parodo

Diamond tools suitable for machining operations of natural stones can be divided into two groups: cutting tools, including blades, the circular blades and the wires, and the surface machining ones, involving mills and grinders, that can be of different shapes. For the stone sawing process, the most adopted tool type is the diamond mill, whose duration and performance are influenced by various elements such as: the mineralogical characteristics of the material to be machined; the working conditions such as the depth of cut, the feed rate and the spindle speed; the production process of the diamond segment and the characteristics of both the matrix and the diamond, such as the size, the type and the concentration of the diamonds and the metal bond formulation hardness. This work allows to indirectly assess the wear of sintered diamond tools by signal analysis (in time and frequency domain) of the cutting force components acquired in the process. The results obtained represent a fundamental step for the development of a sensory supervision system capable of assessing the tool wear and hence to modify the process parameters in process, in order to optimize cutting performance and tool life.


2021 ◽  
Author(s):  
Hüseyin Gürbüz ◽  
Şehmus Baday

Abstract Although Inconel 718 is an important material for modern aircraft and aerospace, it is a kind material, which is known to have low machinability. Especially, while these types of materials are machined, high cutting temperatures, BUE on cutting tool, high cutting forces and work hardening occur. Therefore, in recent years, instead of producing new cutting tools that can withstand these difficult conditions, cryogenic process, which is a heat treatment method to increase the wear resistance and hardness of the cutting tool, has been applied. In this experimental study, feed force, surface roughness, vibration, cutting tool wear, hardness and abrasive wear values that occurred as a result of milling of Inconel 718 material by means of cryogenically treated and untreated cutting tools were investigated. Three different cutting speeds (35-45-55 m/min) and three different feed rates (0.02-0.03-0.04 mm/tooth) at constant depth of cut (0.2 mm) were used as cutting parameters in the experiments. As a result of the experiments, lower feed forces, surface roughness, vibration and cutting tool wear were obtained with cryogenically treated cutting tools. As the feed rate and cutting speed were increased, it was seen that surface roughness, vibration and feed force values increased. At the end of the experiments, it was established that there was a significant relation between vibration and surface roughness. However, there appeared an inverse proportion between abrasive wear and hardness values. While BUE did not occur during cryogenically treated cutting tools, it was observed that BUE occurred in cutting tools which were not cryogenically treated.


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.


2006 ◽  
Vol 315-316 ◽  
pp. 588-592 ◽  
Author(s):  
Wei Zhao ◽  
Ning He ◽  
Liang Li ◽  
Z.L. Man

High speed milling experiments using nitrogen-oil-mist as cutting medium were undertaken to investigate the characteristics of tool wear for Ti-6Al-4V Alloy, a kind of important and commonly used titanium alloy in the aerospace and automobile industries. Uncoated carbide tools have been applied in the experiments. The cutting speed was 300 m/min. The axial depth of cut and the radial depth of cut were kept constant at 5.0 mm and 1.0 mm, respectively. The feed per tooth was 0.1 mm/z. Optical and scanning electron microscopes have been utilized to determine the wear mechanisms of the cutting tools, and energy spectrum analysis has been carried out to measure the elements distribution at the worn areas. Meanwhile, comparisons were made to discuss the influence of different cutting media such as nitrogen-oil-mist and air-oil–mist upon the tool wear. The results of this investigation indicate that the tool life in nitrogen-oil-mist is significantly longer than that in air-oil-mist, and nitrogen-oil-mist is more suitable for high speed milling of Ti-6Al-4V alloy than air-oil-mist.


Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1515
Author(s):  
Jinxing Wu ◽  
Lin He ◽  
Yanying Wu ◽  
Chaobiao Zhou ◽  
Zhongfei Zou ◽  
...  

Tool-chip friction increases cutting temperature, aggravates tool wear, and shortens the service life of cutting tools. A micro-groove design of the rake face can improve the wear performance of the tool. In this study, we used the finite element simulation “Deform” to obtain the temperature field distribution of the tool rake face. The size of the micro-groove was determined by selecting a suitable temperature field combined with the characteristics of tool–chip flow in the cutting process, and the tool was prepared using powder metallurgy. The three-direction cutting forces and tool tip temperature were obtained by a cutting test. Compared with the original turning tool, the cutting force and cutting temperature of the micro-groove tool were reduced by more than 20%, the friction coefficient was reduced by more than 14%, the sliding energy was reduced and the shear energy was greatly decreased. According to the analysis of tool wear by SEM (scanning electron microscope) and EDS (energy dispersive X-ray spectroscopy), the crater wear, adhesive wear and oxidation wear of the micro-groove tool were lower than those of the original turning tool. In particular, the change in the crater wear area on the rake face of the original tool and the micro-groove tool was consistent with the cutting temperature and the wear width of the flank face. On the whole, the crater wear area and the change rate of the crater wear area of the micro-groove tool were smaller. Due to the proper microgroove structure of the rake face, the tool-chip contact area decreased, and the second rake angle of the tool became larger. Hence, the tool-chip friction, cutting forces, cutting energy consumption were reduced, tool wear was improved, and the service life of the micro-groove tool was five times longer than that of the original tool.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 623 ◽  
Author(s):  
Dervis Ozkan ◽  
Peter Panjan ◽  
Mustafa Sabri Gok ◽  
Abdullah Cahit Karaoglanli

Carbon fiber-reinforced polymers (CFRPs) have very good mechanical properties, such as extremely high tensile strength/weight ratios, tensile modulus/weight ratios, and high strengths. CFRP composites need to be machined with a suitable cutting tool; otherwise, the machining quality may be reduced, and failures often occur. However, as a result of the high hardness and low thermal conductivity of CFRPs, the cutting tools used in the milling process of these materials complete their lifetime in a short cycle, due to especially abrasive wear and related failure mechanisms. As a result of tool wear, some problems, such as delamination, fiber breakage, uncut fiber and thermal damage, emerge in CFRP composite under working conditions. As one of the main failure mechanisms emerging in the milling of CFRPs, delamination is primarily affected by the cutting tool material and geometry, machining parameters, and the dynamic loads arising during the machining process. Dynamic loads can lead to the breakage and/or wear of cutting tools in the milling of difficult-to-machine CFRPs. The present research was carried out to understand the influence of different machining parameters on tool abrasion, and the work piece damage mechanisms during CFRP milling are experimentally investigated. For this purpose, cutting tests were carried out using a (Physical Vapor Deposition) PVD-coated single layer TiAlN and TiN carbide tool, and the abrasion behavior of the coated tool was investigated under dry machining. To understand the wear process, scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) was used. As a result of the experiments, it was determined that the hard and abrasive structure of the carbon fibers caused flank wear on TiAlN- and TiN-coated cutting tools. The best machining parameters in terms of the delamination damage of the CFRP composite were obtained at high cutting speeds and low feed rates. It was found that the higher wear values were observed at the TiAlN-coated tool, at the feed rate of 0.05 mm/tooth.


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.


2018 ◽  
Vol 22 ◽  
pp. 47-54 ◽  
Author(s):  
Mukesh Chaudhari ◽  
M. Senthil Kumar

Aluminum based metal matrix composites (AMMC) have found its applications in the automobile, aerospace, medical, and metal industries due to their superior mechanical properties. Fabricated Aluminum based metal matrix composites require machining to improve the surface finish and dimensional tolerance. Machining should be accomplished by good surface finish by consuming lowest energy and less tool wear. This paper reviews the machining of Aluminum based metal matrix composites to investigate the effect of process parameters such as tool geometry, tool wear, surface roughness, chip formation and also process parameters.


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