Preparation of transparent Y2O3 ceramic via gel casting: Realization of high solid volume via surface modification. Issue 11 (4th June 2019)

• Record Type: Journal Article
• Authors: Liu, Wei; Jin, Lingling; Wang, Shiwei
• Is Part Of: Journal of the American Ceramic Society. Volume 102:Issue 11(2019)
• Page Start: 6414
• Page End: 6421
• Publication Date: 2019-06-04
• Subjects: gel casting -- optical properties -- surface modification -- transparent ceramics -- yttrium; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.16555
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: In this article, isocyanate was adopted to modify Y2 O3 powder for the purpose of preparing transparent Y2 O3 ceramics via gel casting. The modification could enhance the hydration resistance of Y2 O3 powder through the steric hindrance effect. The coating mechanism can be proved by the infrared spectrum of the surface‐modified Y2 O3 powder. Modification could not only prevent Y2 O3 particles from reacting with water, but also prevents agglomeration between particles. The viscosity of the slurry with a solid content of 52.7 vol% is only 0.48 Pa·s at the shear rate of 100 s −1, which is suitable for preparing high‐density compacts by gel casting. The transmittance of the sample (1840°C × 8 h, 1 mm thickness) at 1100 nm reaches 75%. The microstructure of the sintered body is dense with the average grain size of 6.5 μm without obvious impurities nor pores. Five mol% ZrO2 ‐doped Y2 O3 transparent ceramic fairing with the diameter of 5 cm without defects was successfully fabricated by gel casting (52.7 vol% solid volume) and vacuum sintering (1840°C × 8 h).