High temperature fracture toughness of single-layer CrAlN and CrAlSiN hard coatings

Research output: Contribution to journalArticleResearchpeer-review


External Organisational units

  • Department of Nuclear Engineering, University of California Berkeley
  • Plansee Composite Materials GmbH
  • Department for Nanostructured Materials, Jožef Stefan Institute
  • Lawrence Berkeley National Laboratory


Hardness and toughness are among of the most important physical properties of hard coatings and it is important to analyze them at temperatures present during coating applications. CrAlN and CrAlSiN are hard coating materials frequently used in high temperature applications. While both possess high oxidation resistance and thermal stability, they differ in their microstructure. In this work, the fracture toughness of magnetron-sputtered single-layer CrAlN and CrAlSiN hard coatings was determined up to 700 °C by in-situ scanning electron microscopy micro-cantilever deflection tests. The results show a decreasing trend of the fracture toughness with increasing temperature. While both coatings' fracture toughness trends are similar up to 400 °C, they diverge at higher temperatures. In general, the evolution of the fracture toughness with increasing temperature shows similarities to the observed changes in hardness in the same temperature range.


Original languageEnglish
Article number126909
Number of pages7
JournalSurface & coatings technology
Issue number15 March
Early online date29 Jan 2021
Publication statusPublished - 15 Mar 2021