Sputtered Cr1-xAlxN hard coatings with 0.21 ≤ x ≤ 0.46

Corinna Sabitzer

Research output: ThesisDiploma Thesis

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Abstract

Within the scope of this thesis, segmented, triangle-like Cr and Al targets were used for industrial-scale sputter deposition of Cr1-xAlxN films, with various compositions to study the resulting structure-property relation. Two different film architectures, a TiAlN-CrAlN Bilayer and Multilayer, have been synthesized on a TiAlN base layer on the substrates by reactive unbalanced magnetron sputtering to investigate the influence of the Al-content onto film properties. The films were evaluated with respect to their thickness, adhesion, chemical composition, structure, residual stresses, hardness, Young’s modulus and tribological properties. The mean film thickness for the Bi- and the Multilayer was similar, with comparable, moderate adhesion to the substrates. Al/(Al+Cr) atomic-ratios of the Cr1-xAlxN layers between 0.21 and 0.46 were obtained. Consequently, a single-phase cubic film structure was observed, while the Bilayer showed a 100 and the Multilayer no preferred orientation. Relatively low residual stresses were found for the Bi- and the Multilayer compared to other film systems, with slightly higher compressive stresses for the Multilayer than for the Bilayer. For both film architectures, stresses decrease with increasing Al-content, until reaching minimum values at Al/(Al+Cr) atomic-ratios of 0.3-0.4, which corresponds to the samples, that were positioned in front of the central area of the Cr and Al targets. For the Multilayer films, higher hardness values and Young’s moduli were obtained than for the Bilayer. For both, hardness and Young’s moduli increase with increasing Al-content, with highest values for Al/(Al+Cr) atomic-ratios of approximately 0.3. The Bilayer exhibit increased tribological properties during room temperature testing, compared with the Multilayer. However, by increasing the temperature during tribological investigations, the multilayered films indicate less coating wear. Here, the Al-content does not influences the obtained results. Furthermore, it can be concluded that the segmented targets are a good opportunity to analyze the structure-property evolution in an industrial-scaled sputtering system, over a broad compositional range, in one single deposition run.
Translated title of the contributionGesputterte Cr1-xAlxN Hartstoffschichten mit 0.21 ≤ x ≤ 0.46
Original languageEnglish
QualificationDipl.-Ing.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Mitterer, Christian, Supervisor (internal)
Award date16 Dec 2011
Publication statusPublished - 2011

Bibliographical note

embargoed until 17-11-2016

Keywords

  • PVD
  • sputtering
  • CrAlN
  • AlCrN
  • hard coatings
  • structure
  • tribology

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