scholarly journals Wear and MnS Layer Adhesion in Uncoated Cutting Tools When Dry and Wet Turning Free-Cutting Steels

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 556 ◽  
Author(s):  
D. Martinez Krahmer ◽  
S. Hameed ◽  
A. J. Sánchez Egea ◽  
D. Pérez ◽  
J. Canales ◽  
...  
Keyword(s):  
Tool Wear ◽  
Cutting Tool ◽  
Wear Behavior ◽  
Manganese Sulfide ◽  
Cutting Speed ◽  
Hard Metal ◽  
Rake Face ◽  
Machined Surface ◽  
Eds Analysis ◽  
Cutting Speeds

Free-cutting steels are developed to produce large quantities of parts with low mechanical behavior, mainly for automotive sector. These alloys contain phosphorous, lead, sulfur, and manganese that help to improve the machinability and surface roughness. However, due to the toxicity of lead, steel mills in recent years have been focusing on non-toxic steels to produce minimum environmental pollution and better machinability. The present work investigates the tool wear during dry and wet turning of free-cutting steels (SAE 1212, SAE 12L14, and SAE 1215) by using uncoated hard metal inserts at three cutting speeds. Additionally, a EDS analysis was performed to determine the presence of Mn and S elements at the rake face of the cutting tool that can induce a higher adhesion of manganese sulfide (MnS). The results show that the SAE 12L14 steel has the best performance in terms of tool life at different cutting speeds. This difference is maximum at the lowest cutting speed, which gradually decreases with the increase of the cutting speed. The wear behavior is evaluated in the three steel alloys at each cutting speed and, consequently, the tool wear exhibits a slightly better performance in the dry machining condition for higher cutting speeds (180 and 240 m/min), independent of the steel alloy. Finally, EDS analysis confirms the presence of Mn and S elements at the rake face of the inserts machined in dry condition. Hence, MnS is expected to interpose between the machined surface and cutting tool surface to behave similar to tribofilm by reducing the wear on the cutting edge.

scholarly journals Metallurgical and Machinability Characteristics of Wrought and Selective Laser Melted Ti-6Al-4V

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Manikandakumar Shunmugavel ◽  
Ashwin Polishetty ◽  
Junior Nomani ◽  
Moshe Goldberg ◽  
Guy Littlefair
Keyword(s):  
Tool Wear ◽  
Cutting Tool ◽  
Flank Wear ◽  
Research Work ◽  
Cutting Speed ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
Coating Delamination ◽  
All Speeds ◽  
Cutting Speeds

This research work presents a machinability study between wrought grade titanium and selective laser melted (SLM) titanium Ti-6Al-4V in a face turning operation, machined at cutting speeds between 60 and 180 m/min. Machinability characteristics such as tool wear, cutting forces, and machined surface quality were investigated. Coating delamination, adhesion, abrasion, attrition, and chipping wear mechanisms were dominant during machining of SLM Ti-6Al-4V. Maximum flank wear was found higher in machining SLM Ti-6Al-4V compared to wrought Ti-6Al-4V at all speeds. It was also found that high machining speeds lead to catastrophic failure of the cutting tool during machining of SLM Ti-6Al-4V. Cutting force was higher in machining SLM Ti-6Al-4V as compared to wrought Ti-6Al-4V for all cutting speeds due to its higher strength and hardness. Surface finish improved with the cutting speed despite the high tool wear observed at high machining speeds. Overall, machinability of SLM Ti-6Al-4V was found poor as compared to the wrought alloy.

scholarly journals Wear Characteristics of Cutting Tool in Brittle Removal of a Ductile Meta in High-Speed Machining

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1679
Author(s):  
Guosheng Su ◽  
Yuhao Wang ◽  
Zhitao Han ◽  
Peirong Zhang ◽  
Hongxia Zhang ◽  
...  
Keyword(s):  
Tool Wear ◽  
Pure Iron ◽  
High Speed ◽  
Cutting Tool ◽  
Cutting Speed ◽  
Rake Face ◽  
Workpiece Material ◽  
Wear Characteristics ◽  
Ductile Metal ◽  
Cutting Speeds

The contact stress and heating effect between the cutting tool and workpiece in metal machining is symmetrical. However, the symmetry may be destroyed by changes in the workpiece material mechanical properties, such as ductility. The goal of this study is to reveal the wear characteristics of the cutting tool in machining a ductile metal with the cutting speed at which the metal is embrittled by the high-strain-rate-embrittle effect (HSREE). Orthogonal high-speed turning experiments were carried out. Pure iron type DT8 was cut at different cutting speeds, ranging from 1000 m/min to 9000 m/min. The shape and morphology of the chips obtained in the experiment were observed and analyzed by optical microscope and scanning electron microscope (SEM). Tool wear characteristics at different cutting speeds were observed. It shows that the pure iron becomes completely brittle when the cutting speed is higher than 8000 m/min. On the rake face, the coating of the cutting tool bursts apart and peels off. A matrix crack originates in the cutting edge or rake face and extends to the flank face of the cutting tool. The effects of HSREE on the tool wear is discussed. The findings of this study are helpful for choosing a suitable tool for brittle cutting of the ductile metal pure iron with very high cutting speed and solving the problems in machining due to its high ductility and high stickiness.

Evidence of Phase Dependent Tool Wear in Ti-6Al-4V Turning Experiments Using PCD and Carbide Inserts

2012 ◽  
Author(s):  
David J. Schrock ◽  
Patrick Kwon
Keyword(s):  
Phase Transformation ◽  
Tool Wear ◽  
Cutting Speed ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Rake Face ◽  
Work Material ◽  
Significant Difference ◽  
Pcd Tools ◽  
Cutting Speeds

This paper presents evidence of phase transformation in turning titanium work material and discusses its impact on tool wear. Tool wear of polycrystalline diamond inserts was studied in turning experiments on Ti-6Al-4V. Confocal laser scanning microscopy was conducted to analyze the rake face of the turning inserts. At cutting speeds of 61m/min, the rake face exhibited scalloped-shaped, fractured, uneven, and rough wear. This is characteristic of attrition wear. At cutting speeds of 122m/min, wear was smooth and even in nature, which is a typical characteristic of diffusion/dissolution wear. At a cutting speed of 91m/min, the wear was a combination of those observed at speeds of 61m/m and 122m/m. A comparison of the wear on the PCD tools to that of WC-6Co from earlier work is also discussed. A significant difference in wear existed between the two different cutting tool materials at the low cutting speed. This difference in wear was linked to a transition from alpha to beta phase in the titanium work material. Temperature estimates on the rake face of the tool previously extracted from FEM support the possibility of phase transformation at the cutting data tested.

Computational Study of the Effect of Cutting Speeds on Tool Wear during Machining of AISI 316L Steel

2012 ◽  
Vol 622-623 ◽  
pp. 409-413
Author(s):  
Wisansart Satana ◽  
Karuna Tuchinda ◽  
Anantawit Tuchindac ◽  
Surachate Chutima
Keyword(s):  
Tool Wear ◽  
Wear Behavior ◽  
Equivalent Stress ◽  
Equivalent Plastic Strain ◽  
Cutting Speed ◽  
Aisi 316L ◽  
316L Steel ◽  
Von Mises Equivalent Stress ◽  
Von Mises ◽  
Cutting Speeds

This research aims to study the effect of cutting speeds on wear behaviors of TiAlN coated insert during the machining process of AISI 316L steel. Experimental investigation and finite element method were employed. The two-dimensional (2D) plane strain orthogonal cutting model was focused at the initial continuous chip formation. The effect of cutting speeds, i.e. 50, 75,120 and 150 m/min, was studied. The tool wear behavior was then further investigated based on computational results which are temperature, von-mises equivalent stress, equivalent plastic strain and contact pressure. High temperature developed at rake face during high cutting speed, i.e. the cutting speed above 120 m/min, suggesting crater wear or diffusion wear. High equivalent plastic strain, i.e. greater than the fracture strain at failure of AISI 316L steel, were observed all along the tool edge around the contact area suggesting the built up edge (BUE) wear at all cutting speed investigated. The adhesive wear was expected on the edge radius at low cutting speed (50 to 75 m/min) based on the von-mises equivalent stress distributions. The overall severity of sliding wear was found to be around the tool nose due to high contact pressure in all cases. The experiments were also conducted with the tail stock constrained in all experiments to reduce the effect of vibration. The insert tool wear was examined by Scanning Electron Microscope. Wear was observed on flank face and rake face of the insert tools with different wear behavior at different cutting speed which agreed well with computational predictions.

Research on Wear Behavior of Tools while Infeed Cutting Austempered Ductile Iron (ADI) with Ceramic Tools

2007 ◽  
Vol 10-12 ◽  
pp. 605-609
Author(s):  
Xu Hong Guo ◽  
G. Liu ◽  
G.S. Su
Keyword(s):  
Abrasive Wear ◽  
Ductile Iron ◽  
Cutting Tool ◽  
Wear Behavior ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Austempered Ductile Iron ◽  
Rake Face ◽  
Wear Area ◽  
Tools Wear

Cutting tests had been done on the Austempered Ductile Iron (ADI) with ceramic cutting tools. The wear shape of the cutting tool’s surface was observed by the Scanning Electron Microscope (SEM). The micro-wear area of the tools was analyzed with energy spectrum. Study on wear shape and wear mechanisms were done when infeed cutting ADI. The result shows that: the cutting speed is an important factor to the tool wear when infeed cutting ADI with CC650 tool, and with the increase of the cutting speed, the wear value of cutting tool increases obviously. The flank of cutting tool (CC650) has wear land of definite width during cutting, and shows obvious abrasive wear. The crate wear shape of rake face is almost joined to major cutting edge, it is different from the typical crate shape of rake face. Elements Fe, Si and Mg in ADI material diffuses to the surface of cutting tools (CC650) after cutting, the diffusion exacerbates the wear of cutting tools, and the diffusion degree of rake face is larger than that of flank, abrasive wear, adhesive wear and diffusive wear is chief reasons for tools wear.

Cutting Tool Wear and Mechanisms of Chip Formation During High-Speed Machining of Compacted Graphite Iron

2007 ◽  
Author(s):  
Niniza S. P. Dlamini ◽  
Iakovos Sigalas ◽  
Andreas Koursaris
Keyword(s):  
Tool Wear ◽  
Surface Finish ◽  
Failure Criterion ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Tools ◽  
Compacted Graphite Iron ◽  
Crater Wear ◽  
Compacted Graphite ◽  
Cutting Speeds

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.

scholarly journals Milling Inconel 718 Workpiece With Cryogenically Treated And Untreated Cutting Tools

2021 ◽  
Author(s):  
Hüseyin Gürbüz ◽  
Şehmus Baday
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Abrasive Wear ◽  
Inconel 718 ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Cutting Tool Wear ◽  
Feed Force

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.

Microtexture Generation Using Controlled Chatter Machining in Ultraprecision Diamond Turning

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Syed Adnan Ahmed ◽  
Jeong Hoon Ko ◽  
Sathyan Subbiah ◽  
Swee Hock Yeo
Keyword(s):  
Cutting Tool ◽  
Cutting Speed ◽  
Diamond Turning ◽  
Diamond Cutting ◽  
Machined Surface ◽  
Excited Vibration ◽  
Mass And Heat Transfer ◽  
Tool Shank ◽  
Diamond Cutting Tool

This paper describes a new method of microtexture generation in precision machining through self-excited vibrations of a diamond cutting tool. Conventionally, a cutting tool vibration or chatter is detrimental to the quality of the machined surface. In this study, an attempt is made to use the cutting tool's self-excited vibration during a cutting beneficially to generate microtextures. This approach is named as “controlled chatter machining (CCM).” Modal analysis is first performed to study the dynamic behavior of the cutting tool. Turning processes are then conducted by varying the tool holder length as a means to control vibration. The experimental results indicate that the self-excited diamond cutting tool can generate microtextures of various shapes, which depend on the cutting tool shank, cutting speed, feed, and cutting depth. The potential application of this proposed technique is to create microtextures in microchannels and microcavities to be used in mass and heat transfer applications.

Experimental Study on Tool Wear when Machining Super Titanium Alloys: Ti6Al4V and Ti-555

2013 ◽  
Vol 763 ◽  
pp. 51-64
Author(s):  
Mohammed Nouari ◽  
Hamid Makich
Keyword(s):  
Tool Wear ◽  
Temperature Rise ◽  
Wear Behavior ◽  
Flow Direction ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
Wear Process ◽  
Texture Modification ◽  
Wear Modes

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.

scholarly journals Investigation of AlCrN-Coated Inserts on Cryogenic Turning of Ti-6Al-4V Alloy

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1338
Author(s):  
Lakshmanan Selvam ◽  
Pradeep Kumar Murugesan ◽  
Dhananchezian Mani ◽  
Yuvaraj Natarajan
Keyword(s):  
Tool Wear ◽  
Cutting Force ◽  
Physical Vapor Deposition ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machined Surface ◽  
Coated Carbide ◽  
Cryogenic Conditions

Over the past decade, the focus of the metal cutting industry has been on the improvement of tool life for achieving higher productivity and better finish. Researchers are attempting to reduce tool failure in several ways such as modified coating characteristics of a cutting tool, conventional coolant, cryogenic coolant, and cryogenic treated insert. In this study, a single layer coating was made on cutting carbide inserts with newly determined thickness. Coating thickness, presence of coating materials, and coated insert hardness were observed. This investigation also dealt with the effect of machining parameters on the cutting force, surface finish, and tool wear when turning Ti-6Al-4V alloy without coating and Physical Vapor Deposition (PVD)-AlCrN coated carbide cutting inserts under cryogenic conditions. The experimental results showed that AlCrN-based coated tools with cryogenic conditions developed reduced tool wear and surface roughness on the machined surface, and cutting force reductions were observed when a comparison was made with the uncoated carbide insert. The best optimal parameters of a cutting speed (Vc) of 215 m/min, feed rate (f) of 0.102 mm/rev, and depth of cut (doc) of 0.5 mm are recommended for turning titanium alloy using the multi-response TOPSIS technique.

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