Developments in Thermodynamic Models of Deposit-Induced Corrosion of High-Temperature Coatings

Abstract

Degradation caused by silicate deposits limits the lifetime of protective coatings in gas turbine engines. In order to design more durable coating materials and architectures it is important to understand the behavior of ingested debris leading to the formation of deposits on component surfaces, and the subsequent reaction of those deposits with the coating materials. This article reviews recent advances in thermodynamic models and databases capable of predicting these reactions. It also describes the development of modeling approaches to capture key features associated with the intrinsic behavior of debris and deposits, their interaction with dense environmental barrier coatings, and reactions occurring during infiltration of molten deposits into porous or segmented thermal barrier coatings.