Investigating High Temperature Damping Behavior of Plasma Sprayed Ni-Alloy Coatings

In recent year, there has been an increasing trend to design the turbine coating together with the substrate. In this harsh environment, a failure in one quickly leads to a failure in the other. Materials that are used in structural applications are prone to mechanical vibration which when not attenuated, will lead to fatigue of components and shortening of life cycle. Therefore, it is not uncommon to find that it is important to understand the thermal stability and dynamic mechanical properties of coatings as well, which will be used in the dynamic conditions. In addition to these essentially noise reduction and vibration amplitude control motivated objectives, however, mechanical energy dissipation processes also find intrinsic applications in cases where a thorough understanding of the mechanisms responsible for the damping response of the material are required. This article describes the damping behavior and mechanisms that exist in plasma sprayed NiCoCrAlY coatings.