Failure mechanism of YSZ coatings prepared by EB-PVD under partial penetration of CMAS attacking

• Published in: Corrosion science Vol. 203; p. 110339
• Main Authors: Weiwei, Qu, Zehao, Chen, Shusuo, Li, Mengmeng, Wu, Yanling, Pei, Shengkai, Gong
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 15.07.2022; Elsevier BV
• Subjects: Aluminum oxide; CMAS; Crack tips; Cracks; Failure mechanism; Failure mechanisms; Failure modes; Magnesium; Partial penetration; Penetration; Phase transitions; Stress analysis; Thermal barrier coatings; Thermal cycle; Thermal cycling; Yttria-stabilized zirconia; Failure mechanism; Partial penetration; Thermal cycle; Stress analysis; CMAS
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2022.110339

The development of thermal barrier coating has been limited by calcium–magnesium–alumina–silicate (CMAS) corrosion. ~13 wt% YSZ coating under partial penetration of CMAS attacking is used as materials of thermal cycling experiment to exclude the influence of phase transition. Failure modes at boundary of CMAS permeable and impermeable zone at 1100 ℃ and 1250 ℃ are not completely consistent. The boundary of two conditions is inclined to occur vertical, transverse and oblique cracks. However, step-type cracks developed by the vertical crack tip are formed at 1100 ℃, and straight oblique penetrating cracks are formed at 1250 ℃. •Thermal cycling experiments are conducted at 1100 °C and 1250 °C.•Three kinds of cracks are formed at boundary of TBCs coated with and without CMAS.•The stepped oblique cracks are formed in 1100 °C thermal cycling samples.•The oblique cracks formed at 1250 °C are continuous penetrating cracks.•CMAS enrich at the interface between TC and TGO to form anorthite layer at 1250 °C.