Evolution of microstructure and mechanical properties of a graded TiAlON thin film investigated by cross-sectional characterization techniques

Nina Schalk*, Michael Tkadletz, Velislava L. Terziyska, Marco Deluca, Ilse Letofsky-Papst, Jozef Keckes, Christian Mitterer

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

In the last years, quaternary oxynitrides have emerged as a new class of materials due to their tunable properties. Within the present work, a graded TiAl(O)N film was grown by magnetron sputter deposition, using TiAl targets with a Ti/Al atomic ratio of 40/60, constant nitrogen and stepwise increasing oxygen partial pressure over the film thickness. The microstructural evolution of the film was investigated by transmission electron microscopy and synchrotron X-ray nanodiffraction. Complementary, cross-sectional μ-Raman spectroscopy was performed to further validate the phase evolution. The first layer, grown without the addition of oxygen, showed a prevalent wurtzite (w) structure and a subordinate face centered cubic (fcc) phase fraction. The addition of small amounts of oxygen resulted in the stabilization of the fcc-phase and the w-phase vanished. With increasing film thickness and thus, increasing oxygen content, increasing amounts of an additional amorphous phase fraction were observed. In the first layers, tensile in-plain strain was determined, which turns to compressive towards the film surface. Cross-sectional nanonindentation revealed increasing hardness and elastic modulus with increasing oxygen content in the first layers as a result of the w to fcc transition; however, towards the film surface the hardness decreases, which can be related to the increasing amorphous phase fraction.

Original languageEnglish
Pages (from-to)155-161
Number of pages7
JournalSurface and Coatings Technology
Volume359
DOIs
Publication statusPublished - 15 Feb 2019

Keywords

  • Cross-sectional nanoindentation
  • Graded film
  • Sputtering
  • Synchrotron X-ray nanodiffraction
  • TEM
  • TiAlON

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Evolution of microstructure and mechanical properties of a graded TiAlON thin film investigated by cross-sectional characterization techniques'. Together they form a unique fingerprint.

Cite this