Isolating the effect of residual stresses on coating wear by a mechanical stress relaxation technique

Beitrag in einer Fachzeitschrift
(Originalarbeit)


Details zur Publikation

Autor(en): Vierneusel B, Benker L, Tremmel S, Göken M, Merle B
Zeitschrift: Thin Solid Films
Jahr der Veröffentlichung: 2017
Band: 638
Seitenbereich: 159 - 166
ISSN: 0040-6090
Sprache: Englisch


Abstract


Residual stresses play an essential role for the tribological performance of sputtered coatings since compressive residual stresses yield positive effects on wear resistance. As deposition induced residual stresses are always related to the coating microstructure, a combination of different effects is typically assessed if coatings are validated by tribological testing. Therefore, the real effect of residual stresses on the tribological performance of coatings is not entirely clear. The study aims to examine this issue by isolating the residual stress effect from the microstructural impact by mechanical relaxation of the coating after the deposition process. For this purpose, MoS2 coated substrates are mechanically pre-stretched during the coating process and relaxed again afterwards in order to reduce the coating's macroscopic residual stresses. Other samples, which are not pre-stretched but coated inside the same process with identical distance to the target, serve as a reference material. The proper function of the relaxation technique is demonstrated by applying a recently developed method for residual stress measurement, namely the “Focused Ion Beam – Digital Image Correlation” method. Both samples, the relaxed and as-deposited one, were subjected to a tribological pin-on-disk test. The results show that at high compressive residual stress levels, only mild wear at the upper surface inside the contact area occurs. In contrast, at low compressive residual stress levels, wear results from an abrasive material removal inside the contact track but most significantly from additional coating detachments outside the contact area. The observations can be related, firstly, to a superimposition of harmful bending stresses and beneficial compressive residual stresses beneath the contact area and, secondly, to a stress relaxation effect taking place only inside the tribological contact zone. In summary, owing to the developed stress relaxation technique, a microstructurally independent effect of residual stresses on wear resistance of sputtered MoS2-coatings has been proved.



FAU-Autoren / FAU-Herausgeber

Benker, Lisa
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)
Göken, Mathias Prof. Dr.
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)
Merle, Benoit Dr.-Ing.
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)
Tremmel, Stephan Dr.-Ing.
Lehrstuhl für Konstruktionstechnik
Vierneusel, Bernd
Lehrstuhl für Konstruktionstechnik


Zusätzliche Organisationseinheit(en)
Exzellenz-Cluster Engineering of Advanced Materials


Zitierweisen

APA:
Vierneusel, B., Benker, L., Tremmel, S., Göken, M., & Merle, B. (2017). Isolating the effect of residual stresses on coating wear by a mechanical stress relaxation technique. Thin Solid Films, 638, 159 - 166. https://dx.doi.org/10.1016/j.tsf.2017.06.016

MLA:
Vierneusel, Bernd, et al. "Isolating the effect of residual stresses on coating wear by a mechanical stress relaxation technique." Thin Solid Films 638 (2017): 159 - 166.

BibTeX: 

Zuletzt aktualisiert 2018-11-08 um 02:28