Showing papers by "Rao Tummala published in 1975"

Sealing glass composition and process

Abstract: A low temperature glass frit seal composition and process employs a paste including particulate lead glass, an organic vehicle, and small amounts of finely divided TiO2. The TiO2 prevents attack by residual organic vehicle on the lead glass during sealing and adjusts the coefficient of thermal expansion to be compatible with the substrate glass.

Process for increasing the strength of sealing glass

Abstract: The strength of high lead or alkaline earth oxide sealing glass articles is increased by treating the surface of the articles with a solution of dilute nitric acid containing about 1-10 weight percent of concentrated nitric acid in water for the time necessary to remove a thin layer of material from the surface of the article. The purpose of this abstract is to enable the public and the Patent Office to rapidly determine the subject matter of the technical disclosure of the application. This abstract is neither intended to define the invention of the application nor is it intended to be limiting as to the scope thereof.

Bi2 O3 and Al2 O3 containing PbO-ZnO-B2 O3 low temperature sealing glass

Abstract: Sealing glass which may be used for sealing glass plates together at relatively low temperatures. The glass has a softening temperature of about 412°C and has a thermal coefficient of expansion (from room temperature to 300°C) of about 84 × 10-7 per °C. The glass consists substantially of the following constituents in the following proportions:

Process for preparing a copper containing sealing glass

Abstract: A copper oxide containing seal glass is formed by a controlled low temperature process which reduces the formation of seeds in the glass. In one embodiment the glass is prepared in two portions with the first portion containing the high melting oxides and the second portion containing the low melting oxides. The copper oxide is added to the second portion and the two portions are combined to form the seal glass at temperatures below about 800°C which reduces the formation of Cu 2 O crystals in the glass.

Stress corrosion of a low-temperature solder glass

Abstract: The stress corrosion of a typical low-temperature, high-lead vitreous solder glass suitable for sealing TV tubes and other displays was investigated in terms of static, dynamic and button tests. The button tests, which take into account the effects of interactions that occur between various glasses during fabrication of the display assembly, have been found to be extremely useful in selecting sealing glasses for the application, in estimating seal life during product service and in determining the acceleration factors for pretesting the seal prior to use in the field. The time-to-failure of the seal was found to be highly thickness dependent, and, for a given thickness, humidity had a much more pronounced effect than temperature.