Synthesis, Properties and Performance of selected hard and wear resistant Coatings for Metal Cutting Applications

Birgit Ella Friedrich

Research output: ThesisMaster's Thesis

Abstract

Rapid technological development entails a high demand on new materials, which are often difficult to process. Consequently, adjustments of the manufacturing methods are continuously required. In the context of metal machining, the permanent request for an increase in productivity asks for higher cutting speeds and thus cutting tools with superior wear resistance. For this purpose, a wide range of coatings has been developed. In the metal tooling industry, for example, (Ti, Al)N coatings synthesized by chemical (CVD) or physical (PVD) vapor deposition techniques are widely used. To further improve and exceed the properties of these coatings, growing attention is currently drawn towards quaternary material compounds. The present work focuses on Ti1−x−yAlxMeyN coatings (Me = W, Mo or Cr; x ~ 0.30 − 0.55 and y ~ 0.10) deposited onto WC-Co-inserts by means of PVD, more precisely cathodic arc deposition. Longitudinal turning of AISI 316L austenitic stainless steel is utilized to investigate the wear behavior and cutting performance of the coatings. By means of SEM, XRD and friction testing the coating thickness, chemical composition, phase- and microstructure, as well as inherent stress state are correlated with the prevalent wear mechanisms and cutting performance. Overall, several active wear types are identified in this cutting application, such as notch wear, adhesive wear and crater wear. Possible influences on each wear type are analyzed and assessed separately. The notch wear is determined as the dominant wear on the flank face and is therefore used as tool life criterion in all cutting tests. The developed wear behavior on the rake face is found to strongly depend on the titanium/aluminum-ratio of the coating. Also impacts by the alloying elements are discovered. Adding tungsten and molybdenum to the material compound leads, at least to some extent, to reduced crater wear on the rake face. Alloying chromium to the coating, on the other hand, improves the wear resistance only in connection with high titanium-content.
Translated title of the contributionSynthese, Eigenschaften und Performance ausgewählter Hart- und Verschleißschutzbeschichtungen für Schneidanwendungen in der Metallbearbeitung
Original languageEnglish
QualificationDipl.-Ing.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Andersson, Jon, Co-Supervisor (external), External person
  • Johansson Jöesaar, Mats, Supervisor (external), External person
  • Grün, Florian, Supervisor (internal)
Award date25 Jun 2021
Publication statusPublished - 2021

Bibliographical note

embargoed until null

Keywords

  • metal cutting tools
  • PVD-coatings
  • wear
  • wear behavior
  • (Ti
  • Al
  • W)N
  • Mo)N
  • Cr)N
  • 316L austenitic stainless steel
  • IMM-cutting test
  • longitudinal turning

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