Determination of Mechanical Properties of TiN Coating Using a Notched Cylindrical Stainless Steel Substrate
Comprehensive studies of the fracture morphology and the sequence of fracture patterns during tensile loading are important to understand the performance of ceramic coatings during operation. The ceramic coatings are applied to relatively rough surfaces with edges and corners. When the substrate is not perfectly smooth and flat, large stress concentrations are generated in the coated system. The stress concentrations due to the shape of the substrate also affect the initiation and propagation of cracks in the coatings. The mechanical integrity of TiN coating is studied using a new test specimen, known as the Cylindrically-Notched-Tensile (CNT) specimen that can mimic real life situations. The coated specimens under tensile loading are then examined using a scanning electron microscope to study the response of the coatings to the applied loads. The interfacial shear strength of the coatings is determined using the Agrawal-Raj model. Multiple cracks are observed in the coating and the fracture morphology was found to depend on the stress concentration at notch corners.
Jian-Feng Nie and Allan Morton
J. Elambasseril et al., "Determination of Mechanical Properties of TiN Coating Using a Notched Cylindrical Stainless Steel Substrate", Materials Science Forum, Vols. 654-656, pp. 1860-1863, 2010