Reactively sputtered TiN/SiO2 multilayer coatings with designed anisotropic thermal conductivity – From theoretical conceptualization to experimental validation

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung

3 Zitate (Scopus)

Abstract

Wear resistant coatings are frequently used for cutting applications due to their high hardness, chemical stability and low thermal conductivity. The low thermal conductivity is generally believed to redirect the heat generated during cutting into the chip, while the heat transfer into the tool is kept low. However, a low isotropic thermal conductivity of the applied coatings consequently causes high lateral thermal gradients close to the heat affected zone. These gradients in turn might cause local degradation of mechanical properties, increased local wear and pronounced local thermal stress. A promising concept for thermal management during cutting is the use of coatings with designed anisotropic thermal conductivity. Thereby, the heat flow into the tool can be still kept low, while heat dissipation within the coating can be maximized. Following this concept, the focus of this work is the design, deposition and characterization of coatings with tailored anisotropic thermal conductivity. TiN/SiO 2 multilayer coatings with periodicities between ~100 and ~400 nm and different TiN/SiO 2 thickness ratios resulting in theoretical anisotropy factors ranging from ~1.7 to ~4.0 were designed. Subsequently, corresponding coatings were deposited by unbalanced reactive magnetron sputtering to a total thickness of ~12 μm using Ti and Si targets. The multilayers were prepared for cross-sectional measurements of their in-plane and surface measurements of their cross-plane thermal conductivity by time-domain thermoreflectance to successfully verify the predicted anisotropies.

OriginalspracheEnglisch
Aufsatznummer125763
Seitenumfang9
FachzeitschriftSurface & coatings technology
Jahrgang393.2020
Ausgabenummer15 July
Frühes Online-Datum14 Apr. 2020
DOIs
PublikationsstatusVeröffentlicht - 15 Juli 2020

Bibliographische Notiz

Funding Information:
The authors gratefully acknowledge the financial support under the scope of the COMET program within the K2 Center “Integrated Computational Material, Process and Product Engineering (IC-MPPE)” (Project No 859480 ). This program is supported by the Austrian Federal Ministries for Transport, Innovation and Technology ( BMVIT ) and for Digital and Economic Affairs ( BMDW ), represented by the Austrian research funding association ( FFG ), and the federal states of Styria, Upper Austria and Tyrol. The financial support by the Austrian Federal Ministry for Digital and Economic Affairs and the National Foundation for Research, Technology and Development is gratefully acknowledged.

Publisher Copyright:
© 2020 Elsevier B.V.

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