Study of indentation creep of thermal barrier coating systems using cylindrical indenters

Finite element method was used to investigate the creep behavior when cylindrical indenters impressed into thermal barrier coating (TBC) systems. Emphasis was placed on the effects of indenter shape, indenter sizes and applied loads. Three different kinds of indenters were used. They were rigid indenters, elastic indenters and elastic worn indenters. FEM results gave curves of indentation creep depth d as a function of creep time t and Mises stress ahead of the indenters. Some conclusions have been drawn. First, with cylindrical indenters the creep of TBC systems can reach steady state in a short time. Second, the impression depths increase with the increase of indenter sizes and applied stresses. Third, at the same indenter size and stress the impression depth of the worn elastic indenter is deeper than that of the elastic indenter and the rigid indenter. Four, for worn elastic indenters, at the same indenter size and stress the impression depths increase with the increase of the worn rim radius. The study of the indention creep responses of TBC systems with cylindrical indenters gives better understanding of creep performances of TBC systems and it is a basis to determine creep parameters of each layer of TBC systems.