Physicochemical Interaction in the Al2O3–HfO2–Ln2O3 Systems

 

I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Krzhizhanovsky str., 3, Kyiv, 03142, Ukraine
Powder Metallurgy - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2014, #07/08
http://www.materials.kiev.ua/article/1257

Abstract

The experimental findings are used for the first time to refine the prediction of elements in the phase diagrams for Al2O3–HfO2–Ln2O3 systems, which are still to be examined, and the prognosis for three-phase eutectics in the Al2O3-rich regions is experimentally confirmed. It is established that a series of eutectics solidify through cooperative crystallization of the phases. The highest melting temperature in the system is 2820 °С, corresponding to the HfO2 melting point. The minimum melting temperatures in the systems range from 1600 to 1760 °С and correspond to the melting temperatures of the Al2O3-rich three-phase eutectics. Materials in these systems are promising for the development of high-temperature structural composites based on directly solidified two-phase and three-phase eutectics, materials for thermal barrier coatings, materials for solid electrolytes (SOFCs, oxygen sensors, etc.), and refractories.


CERAMIC HFO2, EUTECTIC MATERIALS, INTERACTION, LANTHANIDE OXIDES, OXIDE CERAMIC, PHASE EQUILIBRIA, STATE DIAGRAM