TY - JOUR
T1 - Silicate Deposit Degradation of Engineered Coatings in Gas Turbines
T2 - Progress Toward Models and Materials Solutions
AU - Poerschke, David L.
AU - Jackson, R. Wesley
AU - Levi, Carlos G.
PY - 2017/7/3
Y1 - 2017/7/3
N2 - Modern gas turbines rely on ceramic coatings to protect structural components along the hot gas path. These coatings are susceptible to accelerated degradation caused by silicate deposits formed when ingested environmental debris (dust, sand, ash) adheres to the coatings. This article reviews the current understanding of the deposit-induced failure mechanisms for zirconia-based thermal barrier coatings and silicate environmental barrier coatings. Details of the debris melting and crystallization behavior, the nature of the chemical reactions occurring between the deposits and coatings, and the implications for the thermocyclic durability of the coatings are described. Given the challenges posed in understanding how prospective coating materials and architectures will respond to a broad range of deposit compositions, it is proposed to develop an integrated framework linking thermochemical and thermomechanical models to predict coating durability. Initial progress toward developing this framework, and the requisite research needs, are discussed.
AB - Modern gas turbines rely on ceramic coatings to protect structural components along the hot gas path. These coatings are susceptible to accelerated degradation caused by silicate deposits formed when ingested environmental debris (dust, sand, ash) adheres to the coatings. This article reviews the current understanding of the deposit-induced failure mechanisms for zirconia-based thermal barrier coatings and silicate environmental barrier coatings. Details of the debris melting and crystallization behavior, the nature of the chemical reactions occurring between the deposits and coatings, and the implications for the thermocyclic durability of the coatings are described. Given the challenges posed in understanding how prospective coating materials and architectures will respond to a broad range of deposit compositions, it is proposed to develop an integrated framework linking thermochemical and thermomechanical models to predict coating durability. Initial progress toward developing this framework, and the requisite research needs, are discussed.
KW - Apatite
KW - Environmental barrier coating
KW - Phase equilibria
KW - Rare earth silicate
KW - Rare earth zirconate
KW - Thermal barrier coating
UR - http://www.scopus.com/inward/record.url?scp=85022070509&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85022070509&partnerID=8YFLogxK
U2 - 10.1146/annurev-matsci-010917-105000
DO - 10.1146/annurev-matsci-010917-105000
M3 - Article
AN - SCOPUS:85022070509
SN - 1531-7331
VL - 47
SP - 297
EP - 330
JO - Annual Review of Materials Research
JF - Annual Review of Materials Research
ER -