The Root Cause of Nose and Flank Wear and Their Behavior in Turning Ti-6Al-4V With Carbides and PCD Inserts

2014 ◽  
Author(s):  
Trung Nguyen ◽  
Patrick Kwon ◽  
D. Kang ◽  
Tom Bieler
Keyword(s):  
Flank Wear ◽  
Cutting Tools ◽  
Tool Material ◽  
Hard Phase ◽  
Adhesion Layer ◽  
Electron Backscattered Diffraction ◽  
Root Cause ◽  
Ti Alloys ◽  
Ferrous Metals ◽  
Hexagonal Closed Packed

This paper addresses the root cause for flank and nose wear when machining Ti alloys. In machining ferrous metals, at least the cementite (Fe3C) phase is present as the abrasive contributing to the flank wear. However, most titanium alloys possesses no significant hard phase, which questions the root cause for those wear. In this study, a Ti-6Al-4V bar was turned under various conditions with few grades of uncoated carbide and PCD-insert type tools. The cutting tools were retrieved sporadically after stopping the tuning process in order to examine the wear patterns and their evolution on the tools. The nose and flank wear patterns on the tool inserts were investigated with a confocal microscope. The microstructure of the bar was characterized using Orientation Image Microscope with Electron-Backscattered Diffraction Scan (EBDS). Two distinct types of damages were identified, (a) Micro-fracture at the cutting edge and (b) Scoring markings. Based on the microstructure and the tool wear patterns, this paper claims that both types of damages were caused primarily by the hard orientation of the alpha (α or Hexagonal Closed Packed) crystalline phases and secondarily by the adhesion layer detaching parts of the tool material from the nose and flank surfaces.

The Origin of Flank Wear in Turning Ti-6Al-4V

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Trung Nguyen ◽  
Patrick Kwon ◽  
Di Kang ◽  
Thomas R. Bieler
Keyword(s):  
Cutting Tool ◽  
Flank Wear ◽  
Polycrystalline Diamond ◽  
Confocal Microscope ◽  
Hard Phase ◽  
Adhesion Layer ◽  
Electron Backscattered Diffraction ◽  
Tool Materials ◽  
Orientation Image Microscopy ◽  
Ti Alloys

Unlike ferrous materials, where the cementite (Fe3C) phase acts as an abrasive that contributes to flank wear on the cutting tool, most titanium (Ti) alloys possesses no significant hard phase. Thus, the origin of flank wear is unclear in machining Ti alloys. To address this question, a Ti-6Al-4V bar was turned under various conditions with uncoated carbide and polycrystalline diamond (PCD) inserts, most commonly used tool materials for machining Ti alloys. These inserts were retrieved sporadically while tuning to examine the wear patterns using a confocal microscope. To correlate the patterns with the microstructure of the original bar, the microstructure was carefully characterized using Orientation Image Microscopy™ (OIM) with electron-backscattered diffraction (EBSD). From the wear patterns, two distinct types of damage were identified: (a) microscopic and macroscopic fractures on the cutting edges and (b) scoring marks on flank faces. This paper demonstrates that both types of damage were caused primarily by the heterogeneity in hardness in the α-crystals, where the plane perpendicular to the c-axis in an α-crystal is substantially harder than any other direction in the α-crystal as well as the isotropic β-crystal. In addition to such heterogeneities, adhesion layer, ubiquitous to machining Ti alloys, detaches small fragments of the tool, which resulted in microscopic and macroscopic fractures observed on flank wear.

Analysis of Tool Wear—Part I: Theoretical Models of Flank Wear

1969 ◽  
Vol 91 (3) ◽  
pp. 790-796 ◽  
Author(s):  
A. Bhattacharyya ◽  
I. Ham
Keyword(s):  
Tool Wear ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Tools ◽  
Tool Material ◽  
High Strength ◽  
Theoretical Models ◽  
Flank Surface ◽  
Form Stability ◽  
Sufficient Strength

Cutting tools of sufficient strength against failure by brittle fracture or loss of “form stability” through rise of interface temperatures, still continue to fail by a process of “wear,” which is loss of cutting tool material through gradual interaction between the work and the tool material. Such wear can take place either at the principal flank surface or at the top face of the cutting tool for roughing and semiroughing cuts. Wear may also occur at the auxiliary flank surface resulting in grooving wear during fine machining or machining of high strength materials. The causes for such wear processes include (i) mechanical interaction (abrasion or adhesion and transfer type), (ii) thermochemical interaction (diffusion or chemical reaction). As a part of this investigation on tool wear, two theoretical models have been proposed for explaining mechanical wear at the flank surface. These models explain the nature and characteristics of wear growth and the sensitiveness and dependence of interaction phenomena between the tool-work pair.

Performance Evaluation of Superhard Coatings in Drilling of Ti-6Al-4V Alloy

2017 ◽  
Author(s):  
Dinh Nguyen ◽  
Patrick Kwon ◽  
Vadim Voznyuk ◽  
Dave Kim
Keyword(s):  
Flank Wear ◽  
Weight Ratio ◽  
High Strength ◽  
Production Costs ◽  
Confocal Laser ◽  
Adhesion Layer ◽  
Ti Alloys ◽  
Aerospace Manufacturing ◽  
Catastrophic Fracture ◽  
Superhard Coatings

In the aerospace industry, titanium (Ti) alloys, especially Ti6Al4V, has been extensively used over other light weight alloys due to their high strength-to-weight ratio. However, the material and production costs have been major obstacles in the adoption of Ti alloys for a wide variety of applications. The machining of Ti alloys is one of the most time consuming and expensive mechanical processes in aerospace manufacturing. Based on previous literature on the topic, coated drills have had some degree of success in the drilling of Ti. To further the work, this paper conducts a comparative study in which Ti6Al4V plates are drilled with super hard coated drills such as Diamond-like-Carbon (DLC), AlMgB14 (BAM) and nanocomposite AlCrSiN. The results are compared with those of an uncoated drill bit. Working with a coating supplier, several variations of BAM coating have been applied and used in our drilling experiments. To evaluate the performance of these drills, scanning electron microscopy and confocal laser microscopy were used to assess the wear progress of each drill qualitatively and quantitatively. In drilling Ti alloys, the primary mechanisms of flank wear are abrasion, microscopic fracture (chipping) and attrition, which result in the detachment of the adhesion layer located at the cutting edge. For all the drills, the predominant wear occurs near the margin. From our drilling experiments, it has been observed that AlCrSiN and BAM drills have survived up to 58 holes and over 80 holes, respectively, while both uncoated and DLC drills have experienced catastrophic fracture at less than 40 holes.

scholarly journals Performance Comparison of Al2O3 Cutting Tool with and without Reinforcement of Graphene Nanoplatelets

2021 ◽  
Vol 10 (3) ◽  
pp. 93-96
Author(s):  
A.Gopala Krishna ◽  
R Peddi Raju
Keyword(s):  
Fracture Toughness ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Tools ◽  
Tool Material ◽  
Performance Comparison ◽  
Graphene Nanoplatelets ◽  
Cnc Machining ◽  
Machining Performance ◽  
Composite Tool

Al2O3 is a commonly used cutting tool material for machining cast iron and hard steels. However its low fracture toughness has been its potential drawback to use it for wider applications. In order to improve the fracture toughness, graphene nanoplatelets has been used as the reinforcement. The Al2O3 -TiCN composite have been made by powder metallurgy. The present work compares the performance characteristics of Al2O3 -TiCN with and without graphene nanoplatelets (GNP) in CNC machining. The machining performance of the prepared cutting tools is tested in terms of temperature generated, flank wear, cutting force and surface finish. It is observed that the prepared composite tool with GNP has much improved machining performance over the Al2O3 cutting tool that has no GNP reinforcement. The work has the unique novelty of using GNP as the reinforcement in Al2O3 cutting tool material

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.

An Investigation on Machining Power of EN-AC 48000 Aluminum Alloy Used in Automotive and Aerospace Industries

2009 ◽  
Vol 83-86 ◽  
pp. 704-710 ◽  
Author(s):  
H. Shahali ◽  
Hamid Zarepour ◽  
Esmaeil Soltani
Keyword(s):  
Signal To Noise Ratio ◽  
Cutting Tools ◽  
Tool Material ◽  
Polycrystalline Diamond ◽  
Dimensional Accuracy ◽  
Machining Parameters ◽  
Anova Analysis ◽  
Essential Parameter ◽  
Cutting Velocity ◽  
Coated Carbide

In this paper, the effect of machining parameters including cutting velocity, feed rate, and tool material on machining power of EN-AC 48000 aluminium alloy has been studied. A L27 Taguchi's standard orthogonal array has been applied as experimental design to investigate the effect of the factors and their interaction. Twenty seven machining tests have been accomplished with two random repetitions, resulting in fifty four experiments. EN-AC 48000 is an important alloy in automotive and aerospace industries. Machining of this alloy is of vital importance due to build-up edge and tool wear. Machining power is an essential parameter affecting the tool life, dimensional accuracy, and cutting efficiency. Three types of cutting tools including coated carbide (CD 1810), uncoated carbide (H10), and polycrystalline diamond (CD10) have been used in this study. Statistical analysis has been employed to study the effect of factors and their interactions using ANOVA analysis. Moreover, optimal factor levels have been presented using signal to noise ratio (S/N) analysis. Also, regression model have been provided to predict the machining power. Finally, the results of confirmation tests have been presented to verify and compare the adequacy of the predictive models.

Forecasting Performance of Ceramic Cutting Tool

2017 ◽  
Vol 736 ◽  
pp. 86-90 ◽  
Author(s):  
Vyacheslav Maksarov ◽  
A. Khalimonenko
Keyword(s):  
Electrical Resistance ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Tool Material ◽  
Ceramic Materials ◽  
Specific Electrical Resistance ◽  
Testing Methods ◽  
Microstructural Parameters ◽  
Forecasting Performance ◽  
Nondestructive Testing Methods

The article considers the problems of forecasting the performance of cutting tools equipped with replaceable ceramic cutting bits. It is proposed to forecast the operability of ceramic tools on the ground of dependence between its performance characteristics and the microstructural parameters of the tool material. It is proposed to determine the parameters of ceramic bits microstructure by a nondestructive testing methods based on measuring the specific electrical resistance of ceramic materials. As a result of the study we have undertaken, a relationship was detected between the performance and specific electrical resistance of ceramic cutting tools.

scholarly journals Machining of Iron-Carbon Alloys by the Use of Poly-Crystalline Diamond Cutting Inserts with Internal Cooling

2018 ◽  
Vol 2 (3) ◽  
pp. 57 ◽  
Author(s):  
Manuel Reiter ◽  
Jens Brier ◽  
Friedrich Bleicher
Keyword(s):  
Wear Behavior ◽  
Cutting Tools ◽  
Tool Material ◽  
Internal Cooling ◽  
Diamond Cutting ◽  
Diffusion Effects ◽  
Cutting Inserts ◽  
Abrasive Cutting ◽  
Poly Crystalline Diamond ◽  
Insight Into

Poly-crystalline diamond (PCD) is an extremely tough, synthetically produced cutting tool material, which offers outstanding capabilities concerning wear behavior in abrasive cutting environments. Currently, the primary application of PCD cutting tools is the machining of non-ferrous materials, as the diamond’s carbon high affinity towards iron causes diffusion effects while cutting steel with rising temperature. This effect significantly reduces tool life. To lower the occurring temperature of the cutting process, and therefore avoid the reaction of carbon and iron, a thermal functionalization of the cutting inserts has been investigated. The results give insight into making PCD cutting tools economically usable for the machining of iron-carbon materials.

Comparative Studies on the Cutting Performance of CVD Diamond and DLC Coated Inserts in Turning GFRP Composite Materials

2010 ◽  
Vol 431-432 ◽  
pp. 466-469
Author(s):  
Dong Can Zhang ◽  
Bin Shen ◽  
Fang Hong Sun ◽  
Ming Chen ◽  
Zhi Ming Zhang
Keyword(s):  
Composite Materials ◽  
Flank Wear ◽  
Arc Discharge ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Cutting Performance ◽  
Vacuum Arc ◽  
Reinforced Plastics ◽  
Gfrp Composite

The diamond and diamond-like carbon (DLC) films were deposited on the cobalt cemented tungsten carbide (WC-Co) cutting tools respectively adopting the hot filament chemical vapor deposition (HFCVD) technique and the vacuum arc discharge with a graphite cathode. The scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD) and Raman spectroscopy were used to characterize the as-deposited diamond and DLC films. To evaluate their cutting performance, comparative turning tests were conducted using the uncoated WC-Co and as-fabricated CVD diamond and DLC coated inserts, with glass fiber reinforced plastics (GFRP) composite materials as the workpiece. The research results exhibited that diamond and DLC coated inserts had great advantages in cutting tests compared to uncoated insert. The flank wear of the CVD diamond coated insert maintained a very low value about 50μm before the cutting tool failure occurred. For the DLC coated insert, its flank wear always maintained a nearly constant value of 70~200μm during whole 45 minutes turning process. The flank wear of CVD diamond coated insert was lower than that of DLC coated insert before diamond films peeling off.

scholarly journals Technics Research on Polycrystalline Cubic Boron Nitride Cutting Tools Dry Turning Ti-6AL-4V Alloy Based on Orthogonal Experimental Design

2018 ◽  
Vol 142 ◽  
pp. 03002
Author(s):  
Yunhai Jia ◽  
Lixin Zhu
Keyword(s):  
Surface Roughness ◽  
Experimental Design ◽  
Boron Nitride ◽  
Feed Rate ◽  
Flank Wear ◽  
Cubic Boron Nitride ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Orthogonal Experimental Design ◽  
Polycrystalline Cubic Boron Nitride

Ti-6Al-4V components are the most widely used titanium alloy products not only in the aerospace industry, but also for bio-medical applications. The machine-ability of titanium alloys is impaired by their high temperature chemical reactivity, low thermal conductivity and low modulus of elasticity. Polycrystalline cubic boron nitride represents a substitute tool material for turning titanium alloys due to its high hardness, wear resistance, thermal stability and hot red hardness. For determination of suitable cutting parameters in dry turning Ti-6AL-4V alloy by Polycrystalline cubic boron nitride cutting tools, the samples, 300mm in length and 100mm in diameter, were dry machined in a lathe. The turning suitable parameters, such as cutting speed, feed rate and cut depth were determined according to workpieces surface roughness and tools flank wear based on orthogonal experimental design. The experiment showed that the cutting speed in the range of 160~180 m/min, the feed rate is 0.15 mm/rev and the depth of cut is 0.20mm, ideal workpiece surface roughness and little cutting tools flank wear can be obtained.

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