Glass ceramic toughened with tetragonal zirconia

Patent · Wed Jan 01 00:00:00 EST 1986

OSTI ID:865843

Keefer, Keith D ^[1]; Michalske, Terry A ^[2]

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1. Albuquerque, NM
2. Sandia Park, NM

A phase transformation-toughened glass ceramic and a process for making it are disclosed. A mixture of particulate network-forming oxide, network-modifying oxide, and zirconium oxide is heated to yield a homogeneous melt, and this melt is then heat-treated to precipitate an appreciable quantity of tetragonal zirconia, which is retained at ambient temperature to form a phase transformation-toughened glass ceramic. Nucleating agents and stabilizing agents may be added to the mixture to facilitate processing and improve the ceramic's properties. Preferably, the mixture is first melted at a temperature from 1200.degree. to 1700.degree. C. and is then heat-treated at a temperature within the range of 800.degree. to 1200.degree. C. in order to precipitate tetragonal ZrO.sub.2. The composition, as well as the length and temperature of the heat-treatment, must be carefully controlled to prevent solution of the precipitated tetragonal zirconia and subsequent conversion to the monoclinic phase.

• Research Organization: AT&T
• DOE Contract Number: AC04-76DP00789
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4587224
• OSTI ID: 865843
• Country of Publication: United States
• Language: English

Related Subjects

glass
ceramic
toughened
tetragonal
zirconia
phase
transformation-toughened
process
disclosed
mixture
particulate
network-forming
oxide
network-modifying
zirconium
heated
yield
homogeneous
melt
heat-treated
precipitate
appreciable
quantity
retained
ambient
temperature
form
nucleating
agents
stabilizing
added
facilitate
processing
improve
properties
preferably
melted
1200
degree
1700
range
800
zro
composition
length
heat-treatment
carefully
controlled
prevent
solution
precipitated
subsequent
conversion
monoclinic
phase transformation
carefully controlled
glass ceramic
ambient temperature
zirconium oxide
stabilizing agent
nucleating agents
monoclinic phase
homogeneous melt
tetragonal zro
nucleating agent
/501/