Degradation of zirconia in moisture. (November 2020)

• Record Type: Journal Article
• Authors: Cao, Xueqiang; Vassen, Robert; Wang, Jinshuang; Zou, Binglin; Li, Shibao; Hui, Yu; Yuan, Jieyan; Song, Wenjia; Cao, Qin; Jiang, Jianing; Deng, Longhui; Dong, Shujuan
• Is Part Of: Corrosion science. Volume 176(2020)
• Publication Date: 2020-11
• Subjects: Zirconia -- Degradation -- Moisture -- Residual yttria -- Core/shell structure; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2020.109038
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: The degradation of YSZ coatings in moisture is newly discovered, which could be related to the residual Y2 O3, wate corrosion and oxygen vacancies. A core/shell structure of ZrO2 /Y2 O3 in YSZ crystalline grains has been proved, which is very important to its stability in moisture. Calcination of YSZ above 1100 °C can obviously prevent the corrosion risk in moisture. Abstract: Zirconia especially stabilized by Y2 O3 (YSZ) is an important and popularly used material. We have observed the degradation of YSZ in moisture, and have also revealed the degradation mechanism which could be related to the following three chemical processes: (1) reaction of water with the residual Y2 O3 which is not incorporated into the crystal lattice of ZrO2 ; (2) corrosion of YSZ by water; (3) depletion of Y 3+ from the crystal lattice by water molecule due to oxygen vacancies. A core/shell structure of ZrO2 /Y2 O3 in YSZ crystalline grains has been proved. Calcination of YSZ above 1100 °C can prevent the degradation.