Accession Number : AD0690615

Title :   HIGH TEMPERATURE REACTIONS AND PHASE EQUILIBRIA IN THE STRONTIUM OXIDE-ZIRCONIUM OXIDE SYSTEM.

Descriptive Note : Technical rept. Aug 67-Aug 68,

Corporate Author : AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Simmons,Wilbur C.

Report Date : MAY 1969

Pagination or Media Count : 93

Abstract : An investigation of the strontium oxide-zirconium oxide system by x-ray diffraction, differential thermal analysis. Thermogravimetric, and metallographic analysis has lead to the construction of the equilibrium phase diagram. The diagram is characterized by two compounds. There is a very limited solid solution range on the zirconia rich side (<1%) and on the strontia rich side (<3%). The SR3ZR207 compound was found to be stable from room temperature to 2280C where it decomposed in a peritectic reaction forming SRZR03 plus liquid. Pure zirconia was found to accept less than 0.5% sro in solid solution up to 2050C, above which 5% SRO was taken into cubic solid solution. Strontium zirconate, SRZR03, was found to be in equilibrium with (1) monoclinic zirconia from room temperature to 1110C, (2) tetragonal zirconia from 1110 to 2080C, and (3) cubic zirconia from 2080C to the eutectic at 2290c. The eutectic composition was found to be near 27.5-mole percent SRO. Compositions containing more than 50% SRO were found to be extremely sensitive to moisture in the atmosphere and special precautions were taken to prevent hydration. (Author)

Descriptors :   (*ZIRCONIUM OXIDES, PHASE STUDIES), (*STRONTIUM COMPOUNDS, PHASE STUDIES), (*REFRACTORY MATERIALS, *PHASE STUDIES), OXIDES, X RAY DIFFRACTION, ZIRCONATES, EUTECTICS, DIFFERENTIAL THERMAL ANALYSIS, THERMOGRAVIMETRIC ANALYSIS

Subject Categories : Physical Chemistry
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE