Microwave sintering of multiple articles

Patent · Tue Jul 13 04:00:00 EDT 1993

OSTI ID:6352469

Blake, R D; Katz, J D

A method for microwave sintering of multiple small articles of alumina is described comprising: (a) placing at least two articles of alumina in a sintering chamber located within a sintering container, where each article has a mass of no more than about 50 grams, where said chamber is cylindrical in shape, has a floor, a ceiling, and a sidewall, and has a bed of alumina particles located on said floor, where said container has a square or circular planform, where the container is constructed of insulating material and stabilized zirconia, and where the container is comprised of: (1) a base layer of insulating material having a thickness of from about 0.5 to 2.0 inches; (2) a floor layer of stabilized zirconia having a thickness of from about 0.125 to about 0.25 inch; (3) a cylindrical ring of insulating material having a horizontal thickness of from about 0.125 to about 0.375 inch, where said ring rests upon the floor layer and where the inner surface of the ring is the sidewall of the chamber; (4) a stabilized zirconia element which surrounds the ring and has a horizontal thickness of from about 0.25 to about 2.5 inches; (5) a ceiling layer of insulating material having a thickness of from about 0.25 to about 1.5 inches, and (6) a top layer of stabilized zirconia which has a thickness of from about 0.25 to about 1. 5 inches; (b) heating the container to a hold temperature within a hold temperature range, where said hold temperature range is from about 1,400 to about 1,700 C, and where said hold temperature is the surface temperature of one of said alumina articles; (c) maintaining the sintering container at a temperature within the hold temperature range for from about 5 to about 60 minutes by means of microwave radiation; and (d) cooling the container to a temperature below about 1,350 C at a maximum rate of no more than 30 C per minute, where said cooling rate is maintained below said maximum rate by subjecting the container to microwave radiation.

• Assignee: Dept. of Energy, Washington, DC (United States)
• Patent Number(s): US 5227600; A
• Application Number: PPN: US 7-923298
• OSTI ID: 6352469
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CONFIGURATION
CONTAINERS
CONTROL
COOLING
CYLINDRICAL CONFIGURATION
DESIGN
DIMENSIONS
ELECTROMAGNETIC RADIATION
FABRICATION
MASS
MICROWAVE RADIATION
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
SINTERING
TEMPERATURE CONTROL
THERMAL INSULATION
THICKNESS
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES