Crystalline-amorphous interfaces and their relation to grain boundary films

Technical Report · Mon Feb 03 00:00:00 EST 1992

DOI:https://doi.org/10.2172/5738322· OSTI ID:5738322

Carter, C B ^[1]

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1. Minnesota Univ., Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science

In presence of glass in grain boundaries greatly enhances sintering, in part, because transport of matter along and across the intergranular regions is faster. The glass does not simply act as a catalyst but also changes the character of the interfacial regions. In particular, it tends to encourage faceting of the grains; the scale of this faceting may vary from nanometers to microns. After processing, the glass may remain as a thin layer in the interface during preparation of the polycrystalline compact as was initially demonstrated for Si{sub 3}N{sub 4} and proposed for other ceramics. The glass may also crystallize to form an intergranular crystalline layer or it may withdraw from the planar interfaces into three-grain and four-grain junctions (the dewetting process). The present program has begun to examine how glass affects and interacts with crystalline ceramics. The main aim of the program is to examine how glass moves into and out of grain boundaries and why this movement takes. By understanding this process we will be better able to control this important aspect of many ceramic materials. Since TEM is the main tool used in this investigation, we will continue to develop methods for analyzing interfaces as part of this program.

• Research Organization: Cornell Univ., Ithaca, NY (United States). Dept. of Materials Science and Engineering
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-89ER45381
• OSTI ID: 5738322
• Report Number(s): DOE/ER/45381-3; ON: DE92009812
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CERAMICS
INTERFACES
SINTERING
GLASS
ALUMINIUM OXIDES
AMORPHOUS STATE
GRAIN BOUNDARIES
PROGRESS REPORT
SILICON NITRIDES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CRYSTAL STRUCTURE
DOCUMENT TYPES
FABRICATION
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies
360602 - Other Materials- Structure & Phase Studies