Accession Number : AD0649380

Title :   A STUDY OF THE ZIRCONIA-SCANDIA SYSTEM.

Descriptive Note : Final rept., 1 Oct 65-30 Sep 66,

Corporate Author : IIT RESEARCH INST CHICAGO ILL

Personal Author(s) : Domagala,Robert F.

Report Date : NOV 1966

Pagination or Media Count : 27

Abstract : A tentative diagram for phase relationships in the ZrO2-Sc2O3 system is presented based principally on metallographic analysis of as-cast and annealed specimens of ingots prepared by arc melting together calculated amounts of ZrO2 and Sc2O3. A melting point vs. composition study and a somewhat cursory X-ray investigation were conducted; data from these studies are incorporated in the presentation. Briefly, the ZrO2 -rich region of the system has been left open, since further study is required to define relationships in this portion of the diagram. Two intermediate phases, one at approximately 25 w/o (approximately 23.0 m/o) Sc2O3 (designated gamma) and one at 32 w/o (29.6 m/o) to 42 w/o (39.3 m/o) Sc2O3 (Designated delta), have been positioned. A eutectic L approaches limit of delta + Sc2O3 solid solution has been placed at approximately 55 w/o (52.2 m/o) Sc2O3 and 2450C. There is a broad solubility of Sc2O3 for ZrO2; a single-phase field exists from 77 w/o (74.0 m/o) Sc2O3 to 100% Sc2O3. (Author)

Descriptors :   (*ZIRCONIUM OXIDES, PHASE STUDIES), (*SCANDIUM COMPOUNDS, PHASE STUDIES), OXIDES, SOLUBILITY, MICROSTRUCTURE, EUTECTICS, PHASE DIAGRAMS

Subject Categories : Physical Chemistry
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE