Ammonia-treated phosphate glasses useful for sealing to metals metals

Patent · Tue Jan 01 00:00:00 EST 1991

OSTI ID:867968

Brow, Richard K ^[1]; Day, Delbert E ^[2]

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1. Albuquerque, NM
2. Rolla, MO

A method of improving surface-dependent properties of phosphate glass such as durability and wear resistance without significantly affecting its thermal expansion coefficient is provided which comprises annealing the glass in a dry ammonia atmosphere at temperatures approximating the transition temperature of the glass. The ammonia annealing treatment of the present invention is carried out for a time sufficient to allow incorporation of a thin layer of nitrogen into the surface of the phosphate glass, and the treatment improves the durability of the glass without the reduction in the thermal expansion coefficient that has restricted the effectiveness of prior ammonia treatments. The improved phosphate glass resulting from this method is superior in wear resistance, yet maintains suitable thermal expansion properties so that it may be used effectively in a variety of applications requiring hermetic glass-metal seals.

• 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 5045508
• OSTI ID: 867968
• Country of Publication: United States
• Language: English

Related Subjects

ammonia-treated
phosphate
glasses
useful
sealing
metals
method
improving
surface-dependent
properties
glass
durability
wear
resistance
significantly
affecting
thermal
expansion
coefficient
provided
comprises
annealing
dry
ammonia
atmosphere
temperatures
approximating
transition
temperature
treatment
carried
time
sufficient
allow
incorporation
layer
nitrogen
surface
improves
reduction
restricted
effectiveness
prior
treatments
improved
resulting
superior
maintains
suitable
effectively
variety
applications
requiring
hermetic
glass-metal
seals
applications requiring
expansion coefficient
time sufficient
thermal expansion
phosphate glass
transition temperature
phosphate glasses
wear resistance
metal seal
significantly affecting
ammonia atmosphere
expansion properties
glass resulting
glasses useful
hermetic glass
metal seals
significantly affect
annealing treatment
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