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Evaluation of tool wear mechanisms and tool performance in machining single-phase tungsten

Olsson, Mike LU ; Bushlya, Volodymyr LU ; Lenrick, Filip LU and Ståhl, Jan Eric LU (2021) In International Journal of Refractory Metals and Hard Materials 94.
Abstract

Tungsten is commonly used in cemented carbide tooling solutions and as an alloying element in superalloys and steels. In pure form, as a single-phase tungsten, it is used in nuclear and research facilities. Tungsten is known for its poor machinability resulting in excessive tool wear, which puts high requirements on the selected tooling solution. Also, single-phase tungsten is a highly brittle material, thus often leading to surface damage when machining. In this study, eleven different tool materials: ceramics, coated and uncoated cemented carbide, cermet, PcBN and PCD have been tested in longitudinal turning of high purity tungsten (W > 99.9%) in order to identify suitable tool candidates. Seven cutting tool solutions consistently... (More)

Tungsten is commonly used in cemented carbide tooling solutions and as an alloying element in superalloys and steels. In pure form, as a single-phase tungsten, it is used in nuclear and research facilities. Tungsten is known for its poor machinability resulting in excessive tool wear, which puts high requirements on the selected tooling solution. Also, single-phase tungsten is a highly brittle material, thus often leading to surface damage when machining. In this study, eleven different tool materials: ceramics, coated and uncoated cemented carbide, cermet, PcBN and PCD have been tested in longitudinal turning of high purity tungsten (W > 99.9%) in order to identify suitable tool candidates. Seven cutting tool solutions consistently suffered from excessive tool wear or breakage after a few seconds of engagement time. Only two tool materials, PCD and PVD (TiAlN – TiSiN) coated cemented carbide provided sufficient performance. Analysis of their wear mechanisms with scanning and transmission electron microscopy revealed abrasion, oxidation and cracking of WC grains and diffusional dissolution of WC and Co in case of carbide tools. For PCD tools the main identified mechanisms are abrasion and diffusional dissolution. Cracking, formation of build-up edges, presence of workpiece porosity and W adhesion on the machined surface was found to be responsible for poor surface quality and sub-surface damage. Surface roughness for the PCD ranged within Ra = 1.3–1.7 μm and for the PVD coated carbide tool Ra = 1.0–1.5 μm.

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; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Metal cutting, Tool wear, Tungsten
in
International Journal of Refractory Metals and Hard Materials
volume
94
article number
105379
publisher
Elsevier
external identifiers
  • scopus:85091033976
ISSN
0263-4368
DOI
10.1016/j.ijrmhm.2020.105379
language
English
LU publication?
yes
id
3ad01637-48ec-42a2-bf54-bf0f9a5c64fa
date added to LUP
2020-09-30 08:22:00
date last changed
2021-05-05 05:46:35
@article{3ad01637-48ec-42a2-bf54-bf0f9a5c64fa,
  abstract     = {<p>Tungsten is commonly used in cemented carbide tooling solutions and as an alloying element in superalloys and steels. In pure form, as a single-phase tungsten, it is used in nuclear and research facilities. Tungsten is known for its poor machinability resulting in excessive tool wear, which puts high requirements on the selected tooling solution. Also, single-phase tungsten is a highly brittle material, thus often leading to surface damage when machining. In this study, eleven different tool materials: ceramics, coated and uncoated cemented carbide, cermet, PcBN and PCD have been tested in longitudinal turning of high purity tungsten (W &gt; 99.9%) in order to identify suitable tool candidates. Seven cutting tool solutions consistently suffered from excessive tool wear or breakage after a few seconds of engagement time. Only two tool materials, PCD and PVD (TiAlN – TiSiN) coated cemented carbide provided sufficient performance. Analysis of their wear mechanisms with scanning and transmission electron microscopy revealed abrasion, oxidation and cracking of WC grains and diffusional dissolution of WC and Co in case of carbide tools. For PCD tools the main identified mechanisms are abrasion and diffusional dissolution. Cracking, formation of build-up edges, presence of workpiece porosity and W adhesion on the machined surface was found to be responsible for poor surface quality and sub-surface damage. Surface roughness for the PCD ranged within R<sub>a</sub> = 1.3–1.7 μm and for the PVD coated carbide tool R<sub>a</sub> = 1.0–1.5 μm.</p>},
  author       = {Olsson, Mike and Bushlya, Volodymyr and Lenrick, Filip and Ståhl, Jan Eric},
  issn         = {0263-4368},
  language     = {eng},
  month        = {01},
  publisher    = {Elsevier},
  series       = {International Journal of Refractory Metals and Hard Materials},
  title        = {Evaluation of tool wear mechanisms and tool performance in machining single-phase tungsten},
  url          = {http://dx.doi.org/10.1016/j.ijrmhm.2020.105379},
  doi          = {10.1016/j.ijrmhm.2020.105379},
  volume       = {94},
  year         = {2021},
}