Inter-diffusion Induced Strains in Coatings
David Clarke (), Vladimir Tolpygo (Honeywell)
Advancement in Coating Science and Technology
Mon 2:40 - 4:00
RI Hall 108
During use at high-temperatures, inter-diffusion occurs between the single crystal superalloy blade and the oxidation resistant outer coating. This occurs whether the coating is covered with an oxide top-coat to form a thermal barrier coating (TBC)system or not. In this talk we will describe the inter-diffusion induced strains produced in bi-strips of single crystal NiAl bonded to a N5 superalloy. Inter-diffusion causes the initially flat bi-strip to curl and the net curvature decreases with annealing time as inter-diffusion takes place. The observations will be described in detail together with the consequences for both thermal-cycling induced rumpling and TBC life.