Effect of silicon content on PVD film mechanical properties and cutting performance of coated cemented carbide inserts

• Published in: Surface & coatings technology 2013-12, Vol.237, p.379-389
• Main Authors: Bouzakis, K.-D., Bouzakis, E., Kombogiannis, S., Paraskevopoulou, R., Skordaris, G., Makrimallakis, S., Katirtzoglou, G., Pappa, M., Gerardis, S., M’Saoubi, R., Andersson, J.M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Austenitic stainless steels; Cemented carbides; Coating effects; Coatings; Cross-disciplinary physics: materials science; rheology; Cutting performance; Cutting speed; Exact sciences and technology; Fatigue (materials); Impact resistance; Inserts; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Nanostructure; Physics; Production techniques; PVD coatings; Si content; Silicon; Surface treatment; Surface treatments
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2013.06.044

The paper investigates the effect of Si content on TiAlSiN, TiSiN and TiAlN/TiSiN films mechanical strength, brittleness, fatigue and adhesion. The films used were deposited on cemented carbide inserts by employing cathodic arc evaporation. For determining coating strength properties, nanoindentations were carried out. Based on the data acquired and a FEM continuous simulation of nanoindentation, elasto-plastic laws for the films were determined. The adhesion of the coatings was evaluated by inclined impact tests and by Rockwell indentations. The fatigue of the examined coatings, at ambient and elevated temperatures, was characterized via perpendicular impact tests. Moreover, nano-impact tests were conducted for capturing the influence of Si-content on film brittleness. The cutting performance of the coated cemented carbide inserts was tested in milling stainless steel 304L at various cutting speeds. According to the obtained results, the beneficial effect of Si on the cutting performance of PVD coated tools was detected within an optimum cutting speed range. In addition, a superficial TiSiN layer on TiAlN coated cemented carbide tools leads to improved compound mechanical properties. These properties, as well as the cutting performance, depend on the TiSiN-film Si content and coating structure. •Coated tools properties and cutting performance are affected by the film Si content.•TiAlN, TiAlSiN, TiSiN and bilayer TiAlN/TiSiN of different Si content were examined.•Films’ strength, adhesion, fatigue and brittleness were tested by innovative methods.•Si up to 8% improves neither properties nor cutting performance of TiAlN films.•TiSiN and bilayer TiAlN/TiSiN coatings increase the tool life depended on Si content.