Abstract: Glasses in the Ca—Al—Si system are useful in forming optical components for use in telecommunication systems. The glasses include, in mole percent: SiO2 present in an amount of about 6 to about 60 percent, Ga2O3, Al2O3, or a combination thereof present in an amount of about 12 to about 31 percent, and CaO present in an amount of about 20 to about 65 percent.

Abstract: Glasses in the Ca—Al—Si system are useful in forming optical components for use in telecommunication systems. The glasses include, in mole percent: SiO2 present in an amount of about 6 to about 60 percent, Ga2O3, Al2O3, or a combination thereof present in an amount of about 12 to about 31 percent, and CaO present in an amount of about 20 to about 65 percent.

Abstract: The present invention is directed at a glass-ceramic having high strength and toughness and containing miserite as a predominant crystal phase. The glass-ceramic has a composition calculated in terms of a weight percent on the oxide basis comprising 40-68% SiO.sub.2, 12-35% CaO, 8-20% CaF.sub.2, 4-10.5% K.sub.2 O, 0-5% Al.sub.2 O.sub.3, 0-5% B.sub.2 O.sub.3, 0-15% P.sub.2 O.sub.5, 0-4% R.sub.2 O.sub.3, wherein R represents Y.sup.3+ and rare earth metals in the lanthanide series, and 0-5% of optional constituents selected from the group consisting of MgO, SrO, BaO, Na.sub.2 O, Nb.sub.2 O.sub.5, ZrO.sub.2, and ZnO, and 0-10% of optional constituents selected from the group consisting of Nb.sub.2 O.sub.5 and TiO.sub.2 and 0-2% Li.sub.2 O as an optional constituent. The glass-ceramic may contain secondary phases of cristobalite (SiO.sub.2), fluorite (CaF.sub.2), xonotlite (Ca.sub.6 Si.sub.6 O.sub.17 F.sub.2), and fluorapatite (Ca.sub.5 (PO.sub.4).sub.

Abstract: This invention is directed to the production of thermally crystallizable glasses which, upon heat treatment in contact with alumina particulates, will form a strong glass-ceramic-bonded composite body, the excellent bonding being attributed to the presence of lithium aluminoborate crystals. The glass-ceramic composition consists essentially, in weight percent, of______________________________________ SiO.sub.2 25-55 MgO 0-12 B.sub.2 O.sub.3 35-65 Li.sub.2 O + MgO 4-16. Li.sub.

Abstract: An article of manufacture comprising protectively coated titanium, titanium alloy or titanium aluminide, and a method for making it, wherein the protective coating is an adherent crystalline alkaline earth silicate glass-ceramic coating having a composition consisting essentially, in weight percent on the oxide basis, of about 20-75% total of oxides selected in amounts not exceeding the indicated proportions from the group consisting of up to about 50% BaO, 55% SrO, and 35% CaO, 25-60% of SiO.sub.2 and, as optional constituents, 0-25% MnO, 0-20% MgO, and 0-30% total of other compatible bivalent and trivalent metal oxides. The coating is applied as a continuous glassy coating and is converted to a crystalline glass-ceramic coating by heat treatment.

Abstract: This invention is directed to the formation of glass bonded ceramic composite articles, with particular emphasis on forming abrasive products such as grinding wheels. The glasses consist essentially, in weight percent of 15-35% CaO, 35-55% B.sub.2 O.sub.3, and 10-35% SiO.sub.2, with alumina comprising the preferred abrasive particles being bonded into an abrasive product.

Abstract: There is disclosed a coated article composed of a metal alloy substrate, the metal alloy having a nickel, chromium, cobalt or iron base, and a coating that serves as an oxygen barrier to insulate the metal surface from oxygen attack at temperatures which may range up to 1200.degree. C. The coating comprises a glass-ceramic selected from barium silicate and strontium silicate systems characterized by additives that enable forming a continuous well flowed glass coating prior to setting of the coating by crystallization. These additives include the refractory oxides Al.sub.2 O.sub.3, ZrO.sub.2 and Y.sub.2 O.sub.3, the transition metal oxides MnO, CoO, NiO and FeO, and MgO.

Abstract: For protection against oxidation or other adverse chemical deterioration, substrates such as carbon, intermetallic aluminides, and refractory metal alloys are provided with barrier coatings of an aluminoborate glass-ceramic coating having a composition, in weight percent, of about 10-55% Al.sub.2 O.sub.3, 4-40% B.sub.2 O.sub.3, up to 70% total of RO, wherein RO consists of one or more alkaline earth metal oxides selected in amounts not exceeding the indicated proportions from the group consisting of up to 70% BaO, up to 60% SrO, up to 40% CaO, and up to 25% MgO, up to 35% total of R.sub.2 O, wherein R.sub.2 O consists of one or more alkali metal oxides selected in amounts not exceeding the indicated proportion from the group consisting of up to 35% Na.sub.2 O, up to 30% K.sub.2 O, and up to 15% Li.sub.2 O, up to 25% total of metal oxides selected from the group consisting of ZnO and MnO, up to 30% of SiO.sub.2, and up to 10% F.

Abstract: The present invention is directed to the production of glass-ceramic coatings capable of being fired repeatedly to temperatures in excess of 950.degree. C. without thermal deformation and being especially suitable for application to titanium-stabilized stainless steels. The coatings are highly crystalline, substantially free from alkali metal oxides, and consist essentially, by weight, of:______________________________________ MgO 5-35 CaO 0-35 ZnO 0-25 CaO + ZnO 10-35 Al.sub.2 O.sub.3 0-10 B.sub.2 O.sub.3 0-25 P.sub.2 O.sub.5 0-10 B.sub.2 O.sub.3 + P.sub.2 O.sub.5 4-25 SiO.sub.

Abstract: This invention is directed to means for producing strengthened, transparent glass-ceramic, partially body-crystallized, and surface-crystallized glass articles wherein beta-quartz solid solution constitutes the predominant crystal phase. The inventive method comprises subjecting a glass article consisting essentially, expressed in terms of weight percent, of about 2.5-6% Li.sub.2 O, 0.5-5% RO, wherein RO consists of ZnO and the alkaline earth metal oxides BaO, CaO, MgO, and SrO, 16-25% Al.sub.2 O.sub.3, 64-73% SiO.sub.2, and 3.0-6% RO.sub.2, wherein RO.sub.2 consists of 0-6% TiO.sub.2 and 0-3.5% ZrO.sub.2, to vapors of SO.sub.2 and thereafter heat treating the glass article to cause crystallization in situ thereof.

Abstract: The present invention is concerned with the production of glass-ceramic articles, wherein the predominant crystal phase consists of beta-spodumene solid solution or nepheline, but which have integral surface films containing alpha-iron. The method for producing such articles comprises two general steps. First, a glass article having a composition within a particularly-defined area within the Li.sub.2 O-FeO-Al.sub.2 O.sub.3 -SiO.sub.2 -TiO.sub.2 field or within the Na.sub.2 O-FeO-Al.sub.2 O.sub.3 -SiO.sub.2 -TiO.sub.2 field is heat treated under oxidizing conditions at temperatures of at least about 1000.degree. C. to cause crystallization in situ of the glass to a glass-ceramic article wherein beta-spodumene solid solution or nepheline crystals constitute the predominant crystal phase in the interior of the article and, at the same time, an integral surface layer containing hematite crystals is developed.

Abstract: The instant invention is concerned with the preparation of iron-containing glasses having compositions within the R.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 field, wherein R.sub.2 O consists of Li.sub.2 O, Na.sub.2 O, and/or K.sub.2 O, which spontaneously develop thin surface layers containing hematite (alpha-Fe.sub.2 O.sub.3) crystals when exposed to relatively low temperature heat treatments, viz., at least about 675.degree. C. but less than about 950.degree. C., in an oxidizing environment. Described visually, the resulting surfaces exhibit a variety of appearances, ranging from mirror-like through lustrous metallic to dull-earthen. In all surface layers, the hematite crystals may subsequently be chemically reduced to magnetite (Fe.sub.3 O.sub.4) or metallic iron crystals. Permanent magnetization can then be induced by means of the application of a strong magnetic force. The magnetite-containing surfaces can also demonstrate semiconductivity. The metallic iron surface can be highly electrically conductive.

Abstract: The instant invention relates to the production of glass-ceramic articles, wherein the predominant crystal phase is beta-quartz solid solution and/or beta-spodumene solid solution, but which have a thin, integral, tightly-bonded surface film containing crystals exhibiting the structure of magnetite. The preferred method of production for such articles requires three general steps. First, a glass article having a particular composition within the Li.sub.2 O--FeO--Al.sub.2 O.sub.3 --SiO.sub.2 field nucleated with TiO.sub.2 is heat treated in air or other oxidizing atmosphere to yield a glass-ceramic article through the crystallization in situ of beta-quartz solid solution and/or beta-spodumene solid solution crystals. Simultaneously during this heat treatment, a surface layer containing hematite is developed. Second, the glass-ceramic article is subjected to a hot acid bath. Third, the acid-washed article is heat treated in a H.sub.