AVS 58th Annual International Symposium and Exhibition
    Tribology Focus Topic Thursday Sessions
       Session TR-ThA

Paper TR-ThA8
Study of Failure Mechanisms of a PVD TiAlN Coating by an Impact-Sliding Tester

Thursday, November 3, 2011, 4:20 pm, Room 111

Session: Advanced Tribological Materials
Presenter: JunFeng Su, University of Windsor, Canada
Authors: J.F. Su, University of Windsor, Canada
X. Nie, University of Windsor, Canada
Correspondent: Click to Email
Physical vapor deposition (PVD) coatings usually have high hardness and wear resistance and have been considered as necessary top layers of a wide variety of mechanical components to battle the wear problems. One of applications of hard PVD coatings is used as much-needed protective top layers on surfaces of stamping dies thereby to extend the tool life and improve the quality of the stamped products. Impact fatigue tests have been carried out to investigate the failure behavior of coating-substrate systems under simulated stamping force conditions in our group. However, machining forces on the work pieces are not always only perpendicular to the surface. Tangential or parallel forces are usually involved such as in stamping, milling and turning. In this work, an impact-sliding fatigue tester was proposed as an experimental technique to investigate the failure behavior of coating-substrate systems under shear combined conditions. Each impact-sliding cycle consisted of an 200 N impact force and a 200 N pressing force, respectively. One PVD TiAlN coating on D2 substrates was tested at this combination of impact/pressing loads for 1,500 cycles. Impact-sliding wear track was then observed at cross section obtained by Electrical discharge machining (EDM). Coating failure mechanisms were found to be chipping, peeling, fatigue cracks and material transfer. Fatigue cracks were particularly discussed from the point of view of fracture toughness.