Wear mechanism in end milling of Inconel 718

Nickel-based, creep-resistant, superalloy Inconel 718 is amongst the most difficult alloys to machine. The main reason for the poor machinability of the alloy is the high work-hardening rate by the precipitation of a γ’ phase and the presence of hard abrasive phases such as titanium carbide, niob...

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Main Authors:	Amin, A. K. M. Nurul, Hossain, Ishtiaq, Patwari, Muhammed Anayet Ullah
Format:	Book Chapter
Language:	English
Published:	IIUM Press 2011
Subjects:	TJ Mechanical engineering and machinery
Online Access:	http://irep.iium.edu.my/23611/ http://irep.iium.edu.my/23611/ http://irep.iium.edu.my/23611/4/chp32.pdf

id	iium-23611
recordtype	eprints
spelling	iium-236112012-09-14T00:54:56Z http://irep.iium.edu.my/23611/ Wear mechanism in end milling of Inconel 718 Amin, A. K. M. Nurul Hossain, Ishtiaq Patwari, Muhammed Anayet Ullah TJ Mechanical engineering and machinery Nickel-based, creep-resistant, superalloy Inconel 718 is amongst the most difficult alloys to machine. The main reason for the poor machinability of the alloy is the high work-hardening rate by the precipitation of a γ’ phase and the presence of hard abrasive phases such as titanium carbide, niobium carbide and the Ni3AlTi phase. Generally, increasing the amount of γ’ phase by increasing the amount of titanium and aluminum increases the rate of tool wear [1]. The nickel-based alloys also retain their strength at elevated temperatures and this result in high cutting forces even at high cutting speeds for which high temperatures are generated [2]. It is very complicated to predict tool life in end milling with sufficient accuracy on the basis of controllable process parameters. Nevertheless, it is an essential part of a machining system in the automated factory to change tools automatically due to wear or catastrophic failure. A number of tool materials were used by the researchers in an attempt to increase machinability of Inconel 718 so far, such as, coated tungsten carbide, alumina (Al2O3), SiC whiskerreinforced alumina and cubic boron nitrate (CBN) etc. [3],[4],[5]. Of these materials coated tungsten carbide is the most widely used. Currently, it is estimated that over 80-85% of all carbide tools sold are coated [6]. In general, coated tools perform better when machining nickel-based superalloys due to the coatings increased hardness, ability to act as a barrier to thermal and atomic diffusion and by altering the coefficient of friction [7]. Derrien et al found that TiN coated tools resulted in higher tool life and lower surface roughness that uncoated tools when milling Inconel 718 [8]. Gatto et al recommended that CrN and TiAlN coatings improved tool performance by acting as a thermal barrier and therefore preventing the high temperature generated in the cutting process from softening the substrate [9]. TiAlN and CrN coated carbide tools were compared in end milling of Inconel 718 by Sharman et al [10] and it was found that TiAlN gave on an average three times better performance compared to CrN in terms of metal removal, due to the lower hardness (lower abrasive wear resistance) and higher chemical affinity of CrN to Inconel 718. It concluded that under conditions where thermal rather than mechanical stresses predominate, the TiAlN coating would be expected to give better results. IIUM Press 2011 Book Chapter PeerReviewed application/pdf en http://irep.iium.edu.my/23611/4/chp32.pdf Amin, A. K. M. Nurul and Hossain, Ishtiaq and Patwari, Muhammed Anayet Ullah (2011) Wear mechanism in end milling of Inconel 718. In: Advanced Machining Towards Improved Machinability of Difficult-to-Cut Materials. IIUM Press, Kuala Lumpur, Malaysia, pp. 239-245. ISBN 9789674181758 http://rms.research.iium.edu.my/bookstore/default.aspx
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English
topic	TJ Mechanical engineering and machinery
spellingShingle	TJ Mechanical engineering and machinery Amin, A. K. M. Nurul Hossain, Ishtiaq Patwari, Muhammed Anayet Ullah Wear mechanism in end milling of Inconel 718
description	Nickel-based, creep-resistant, superalloy Inconel 718 is amongst the most difficult alloys to machine. The main reason for the poor machinability of the alloy is the high work-hardening rate by the precipitation of a γ’ phase and the presence of hard abrasive phases such as titanium carbide, niobium carbide and the Ni3AlTi phase. Generally, increasing the amount of γ’ phase by increasing the amount of titanium and aluminum increases the rate of tool wear [1]. The nickel-based alloys also retain their strength at elevated temperatures and this result in high cutting forces even at high cutting speeds for which high temperatures are generated [2]. It is very complicated to predict tool life in end milling with sufficient accuracy on the basis of controllable process parameters. Nevertheless, it is an essential part of a machining system in the automated factory to change tools automatically due to wear or catastrophic failure. A number of tool materials were used by the researchers in an attempt to increase machinability of Inconel 718 so far, such as, coated tungsten carbide, alumina (Al2O3), SiC whiskerreinforced alumina and cubic boron nitrate (CBN) etc. [3],[4],[5]. Of these materials coated tungsten carbide is the most widely used. Currently, it is estimated that over 80-85% of all carbide tools sold are coated [6]. In general, coated tools perform better when machining nickel-based superalloys due to the coatings increased hardness, ability to act as a barrier to thermal and atomic diffusion and by altering the coefficient of friction [7]. Derrien et al found that TiN coated tools resulted in higher tool life and lower surface roughness that uncoated tools when milling Inconel 718 [8]. Gatto et al recommended that CrN and TiAlN coatings improved tool performance by acting as a thermal barrier and therefore preventing the high temperature generated in the cutting process from softening the substrate [9]. TiAlN and CrN coated carbide tools were compared in end milling of Inconel 718 by Sharman et al [10] and it was found that TiAlN gave on an average three times better performance compared to CrN in terms of metal removal, due to the lower hardness (lower abrasive wear resistance) and higher chemical affinity of CrN to Inconel 718. It concluded that under conditions where thermal rather than mechanical stresses predominate, the TiAlN coating would be expected to give better results.
format	Book Chapter
author	Amin, A. K. M. Nurul Hossain, Ishtiaq Patwari, Muhammed Anayet Ullah
author_facet	Amin, A. K. M. Nurul Hossain, Ishtiaq Patwari, Muhammed Anayet Ullah
author_sort	Amin, A. K. M. Nurul
title	Wear mechanism in end milling of Inconel 718
title_short	Wear mechanism in end milling of Inconel 718
title_full	Wear mechanism in end milling of Inconel 718
title_fullStr	Wear mechanism in end milling of Inconel 718
title_full_unstemmed	Wear mechanism in end milling of Inconel 718
title_sort	wear mechanism in end milling of inconel 718
publisher	IIUM Press
publishDate	2011
url	http://irep.iium.edu.my/23611/ http://irep.iium.edu.my/23611/ http://irep.iium.edu.my/23611/4/chp32.pdf
first_indexed	2023-09-18T20:35:41Z
last_indexed	2023-09-18T20:35:41Z
_version_	1777409029746720768

Wear mechanism in end milling of Inconel 718

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