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Wear behaviour of PVD (Ti,Si)N-(Ti,Al)N coated cemented carbide in down milling pearlitic compacted graphite iron

Bello Bermejo, Juan Manuel LU orcid ; Lindvall, Rebecka LU ; Saatçi, Berk ; Ståhl, Jan Eric LU ; Åberg, Lena Magnusson ; Bohlin, Oskar and Windmark, Christina LU orcid (2025) In Wear
Abstract

Compacted graphite iron (CGI) is an intermediate material between conventional grey cast iron and the stronger, more wear resistant ductile iron, making it a suitable material choice for different automotive applications. The improved material properties of CGI as to conventional grey cast iron makes it more difficult to machine, and finding a suitable tool material with low wear rates is a challenge and remains largely unexplored in research. This study examines the performance of multilayer PVD (Ti,Si)N-(Ti,Al)N coated cemented carbide round inserts at varying cutting data parameters in the down face dry milling of pearlitic CGI grade EN-GJV-450. Eight different cutting conditions, with a cutting speed range vc = 154–461... (More)

Compacted graphite iron (CGI) is an intermediate material between conventional grey cast iron and the stronger, more wear resistant ductile iron, making it a suitable material choice for different automotive applications. The improved material properties of CGI as to conventional grey cast iron makes it more difficult to machine, and finding a suitable tool material with low wear rates is a challenge and remains largely unexplored in research. This study examines the performance of multilayer PVD (Ti,Si)N-(Ti,Al)N coated cemented carbide round inserts at varying cutting data parameters in the down face dry milling of pearlitic CGI grade EN-GJV-450. Eight different cutting conditions, with a cutting speed range vc = 154–461 m/min and feed per tooth range fz = 0.277–0.554 mm/rev were evaluated. As-worn tools are studied and later cross-sectioned to be further analysed under a scanning electron microscope (SEM). The primary wear mechanisms identified included adhesion, abrasive wear, thermal crack formation, particularly comb cracks, and diffusional dissolution of WC and Co. Cobalt diffusion from the binder into the CGI material, along with a potential tungsten oxidation within cracks, led to significant tool degradation, forming Co carbides and Fe-doped WO3, respectively. The interaction between CGI material and the PVD coating also resulted in the formation of a Mg-Si-O rich layer atop (Ti,Si)N-(Ti,Al)N coating, which could potentially act as a protective barrier. Additionally, in some conditions due to outward diffusion from WC grains together with Fe form a strong carbide Tool Protection Layer (TPL) which is developed as flank built-up edge atop the exposed cemented carbide, potentially extending tool life by reducing further wear.

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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
Cemented carbide, CGI, Milling, PVD, Wear
in
Wear
article number
205891
pages
14 pages
publisher
Elsevier
external identifiers
  • scopus:85217935011
ISSN
0043-1648
DOI
10.1016/j.wear.2025.205891
language
English
LU publication?
yes
id
220b6fd7-6500-4f7f-aba3-118beeb13961
date added to LUP
2025-03-03 08:22:50
date last changed
2025-04-08 13:58:58
@article{220b6fd7-6500-4f7f-aba3-118beeb13961,
  abstract     = {{<p>Compacted graphite iron (CGI) is an intermediate material between conventional grey cast iron and the stronger, more wear resistant ductile iron, making it a suitable material choice for different automotive applications. The improved material properties of CGI as to conventional grey cast iron makes it more difficult to machine, and finding a suitable tool material with low wear rates is a challenge and remains largely unexplored in research. This study examines the performance of multilayer PVD (Ti,Si)N-(Ti,Al)N coated cemented carbide round inserts at varying cutting data parameters in the down face dry milling of pearlitic CGI grade EN-GJV-450. Eight different cutting conditions, with a cutting speed range v<sub>c</sub> = 154–461 m/min and feed per tooth range f<sub>z</sub> = 0.277–0.554 mm/rev were evaluated. As-worn tools are studied and later cross-sectioned to be further analysed under a scanning electron microscope (SEM). The primary wear mechanisms identified included adhesion, abrasive wear, thermal crack formation, particularly comb cracks, and diffusional dissolution of WC and Co. Cobalt diffusion from the binder into the CGI material, along with a potential tungsten oxidation within cracks, led to significant tool degradation, forming Co carbides and Fe-doped WO<sub>3</sub>, respectively. The interaction between CGI material and the PVD coating also resulted in the formation of a Mg-Si-O rich layer atop (Ti,Si)N-(Ti,Al)N coating, which could potentially act as a protective barrier. Additionally, in some conditions due to outward diffusion from WC grains together with Fe form a strong carbide Tool Protection Layer (TPL) which is developed as flank built-up edge atop the exposed cemented carbide, potentially extending tool life by reducing further wear.</p>}},
  author       = {{Bello Bermejo, Juan Manuel and Lindvall, Rebecka and Saatçi, Berk and Ståhl, Jan Eric and Åberg, Lena Magnusson and Bohlin, Oskar and Windmark, Christina}},
  issn         = {{0043-1648}},
  keywords     = {{Cemented carbide; CGI; Milling; PVD; Wear}},
  language     = {{eng}},
  month        = {{02}},
  publisher    = {{Elsevier}},
  series       = {{Wear}},
  title        = {{Wear behaviour of PVD (Ti,Si)N-(Ti,Al)N coated cemented carbide in down milling pearlitic compacted graphite iron}},
  url          = {{http://dx.doi.org/10.1016/j.wear.2025.205891}},
  doi          = {{10.1016/j.wear.2025.205891}},
  year         = {{2025}},
}