Comparative Investigation on the Mechanical Properties of Thermal Barrier Coatings Made by Atmospheric Plasma Spaying and Suspension Plasma Spraying

摘要

In the present work fundamental mechanical properties of both SPS and APS coatings were investigated. Four point bending test of coated samples revealed lower values of Young's modulus for as-sprayed SPS than APS coatings. Measurements of interfacial toughness between the YSZ top coating and the CoNiCrAlY-based bond coating showed higher values for SPS coatings. Low stiffness of SPS coatings limits elastic energy stored in the ceramic coating. This coupled with good interfacial toughness might make SPS coatings less prone to delamination under various thermomechanical loading conditions such as these encountered during thermal cycling.