Ammonia-treated phosphate glasses useful for sealing to metals

Patent · Tue Sep 03 04:00:00 EDT 1991

OSTI ID:7276720

Brow, R K; Day, D E

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.

• DOE Contract Number: AC04-76DP00789
• Assignee: Dept. of Energy, Washington, DC (United States)
• Patent Number(s): US 5045508; A
• Application Number: PPN: US 7-516935
• OSTI ID: 7276720
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360603 -- Materials-- Properties
360606 -- Other Materials-- Physical Properties-- (1992-)
AMMONIA
ANNEALING
ATMOSPHERES
CONTROLLED ATMOSPHERES
EXPANSION
GLASS
HEAT TREATMENTS
HYDRIDES
HYDROGEN COMPOUNDS
MECHANICAL PROPERTIES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
PHOSPHATE GLASS
SURFACE TREATMENTS
THERMAL EXPANSION
USES
WEAR RESISTANCE