15th annual conference on composites and advanced ceramics

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5681294

Bansal, N P; Hyatt, M J; Drummond, III, C H

Powders of roller quenched (Sr,Ba)O-Al{sub 2}O{sub 3}-{sup 2}SiO{sub 2} glasses of various compositions were uniaxially pressed into bars and hot isostatically pressed at 1350{degree}C for 4 hours or cold isostatically pressed and sintered at different temperatures between 800 to 1500{degree}C for 10 or 20 hours. Densities, flexural strengths, and linear thermal expansion were measured for three compositions. The glasss transition and crystallization temperatures were determined by Differential Scanning Calorimetry (DSC). The liquidus and crystallization temperature from the melt were measured using high temperature Differential Thermal Analysis (DTA). Crystalline phases formed on heat treatment of the glasses were identified by powder x ray diffraction. In Sr containing glasses, the monoclinic celsian phase always crystallized at temperatures above 1000{degree}C. At lower temperatures, the hexagonal analog formed. The temperature for orthorhombic to hexagonal structure transformation increased monotonically with SrO content, from 327{degree}C for BaO-Al{sub 2}O{sub 3}-{sup 2}SiO{sub 2} to 758{degree}C for SrO-Al{sub 2}O{sub 3}-{sup 2}SiO{sub 2}. These glass powders can be sintered to almost full densities and monoclinic celsian phase at a relatively low temperature of 1100{degree}C.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
• OSTI ID: 5681294
• Report Number(s): N-91-19308; NASA-TM--103764; E--6027; NAS--1.15:103764; CONF-910162--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BARIUM COMPOUNDS
BARIUM OXIDES
CERAMICS
CHALCOGENIDES
CRYSTAL STRUCTURE
CRYSTALLIZATION
DENSITY
EXPANSION
FABRICATION
FLEXURAL STRENGTH
GLASS
HEAT TREATMENTS
HIGH TEMPERATURE
HOT PRESSING
LOW TEMPERATURE
MATERIALS WORKING
MECHANICAL PROPERTIES
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PRESSING
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SINTERING
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
THERMAL ANALYSIS
THERMAL EXPANSION
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE