Non-Linear Mechanical Behavior of Plasma Sprayed Coatings Under Mechanical and Thermal Loading

Mechanical response of plasma sprayed ceramic coatings to mechanical and
thermal loading of various extent was studied. Coated samples were
subjected to four-point bending, with coatings loaded in tension and
compression, respectively. Thermal loading was provided by heating the
samples, while stresses were generated by thermal mismatch between the
coatings and substrates. In both cases, cyclic loading was applied.
Non-linear behavior and significant hystereses were observed, indicating
inelastic phenomena taking place. Mechanical tests were complemented by
structural observations in SEM and FEM modeling of the mechanical
properties based on real structures. Relevant structural features and
possible mechanisms underlying this behavior are discussed.