The binary phase diagram of ZrO2-CaO includes the eutectic of the CaZrO3 phase and the CaO-stabilised ZrO2 phase. In this study, Ca(Zr1-xHfx)O3/(Zr1-xHfx)O2 (x=0, 1/3, 0.5) eutectic film was prepared by rapid solidification process using high power laser irradiation method. CaCO3 of 99.9% purity, ZrO2 and HfO2 of 98% purity powders were used as starting materials. The coating process was performed in an electric furnace at 1300°C. Solidified film with fine lamellar structure was obtained. When the Zr site was substituted with Hf, the lamellar spacing increased with the amount of substitution. Separate from the solidification film prepared by laser irradiation, a rapidly solidifying sample with x=0.1 composition was prepared using an optical floating zone apparatus. The melt of the sample was free-falling onto a copper dish. No film-like rapidly solidified sample was obtained. Hf ion was homogeneously solid-soluble in both phases of CaZrO3 and ZrO2. This study attempted to prepare eutectic solidification coatings for CaHfO3/HfO2 eutectic under the same conditions as for CaZrO3/ZrO2 eutectic coatings. No eutectic structure was obtained.
Author (s) Details
Shunkichi Ueno
College of Engineering, Nihon University, Koriyama, Fukushima 963-8642,
Japan.
Please see the book here:- https://doi.org/10.9734/bpi/cmsrf/v4/5468
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