Abstract: There is disclosed an integral vitreous article composed of an opaque portion encased within a thin surface layer of transparent, colored glass. The article has a uniform chemical composition of an alkaline aluminosilicate nature, the opaque portion contains light scattering particles of a titaniferous nature, and the surface layer contains a titania coupled colorant. The article may be produced by simultaneously forming an article and quenching its surface whereby differential heat extraction produces the transparent surface layer.

Abstract: There is disclosed an integral vitreous article composed of an opacified interior portion encased within a surface layer of glass that is transparent except for an opacified zone of predetermined configuration. The article may be produced by momentarily contacting an exposed surface on a molten glass charge with a chilling member before forming the glass.

Abstract: This invention is concerned with the production of glass-ceramics especially suitable for incorporating radioactive wastes. The inventive glass-ceramics contain at least two crystal phases selected from the group of pollucite, mullite, monazite, and, optionally, tetragonal or cubic zirconia as the predominant crystal phases and consist essentially, expressed in weight percent on the oxide basis, of 5-40% Cs.sub.2 O, 15-50% Al.sub.2 O.sub.3, 0-30% La.sub.2 O.sub.3 +CeO.sub.2, 0-20% P.sub.2 O.sub.5, 0-30% ZrO.sub.2, 12-65% La.sub.2 O.sub.3 +CeO.sub.2 +P.sub.2 O.sub.5, and 15-50% SiO.sub.2.

Abstract: This invention relates to the production of essentially transparent glass-ceramic sheet useful as surfaces for smoothtop cooking stoves which will display a warm brown coloration sufficiently dark to conceal the heating element when not in use, but permitting visible observation thereof when in operation. The products consist essentially, on an analyzed basis, of 2.5-4.5% Li.sub.2 O, 1-2% MgO, 1-2% ZnO, 19.5-21% Al.sub.2 O.sub.3, 66.5-68% SiO.sub.2, 4-5% TiO.sub.2, and 0.02-0.2% V.sub.2 O.sub.5.

Abstract: There are disclosed a composite optical waveguide characterized by a glass-ceramic coating over a vitreous waveguide member, and methods of producing this composite waveguide by drawing a glass coated waveguide and thermally crystallizing the glass coating.

Abstract: There is disclosed a method of converting a thin glass body, such as a glass fiber or coating, to a corresponding glass-ceramic body by a heat treatment comprising a plurality of heating-cooling cycles.

Abstract: Fine-grained, polycrystalline, basalt-type glass-ceramic fibers, having a crystal content of at least 35% and particular application as fiber reinforcement in concrete structures, are disclosed. A method of production comprises treating a vitreous fiber in the temperature range of 900.degree. to 1250.degree. C. for a time not exceeding ten minutes, and preferably less than one minute.

Abstract: Light-absorbing glass-ceramic articles comprising beta-spodumene and/or beta-quartz as the principal crystal phase and exhibiting blue-to-black coloration are provided by adding a glass reducing agent to a titanium-containing lithium aluminosilicate glass batch for the parent glass.

Abstract: This invention relates to the manufacture of highly-crystalline, opaque glass-ceramic articles, wherein the primary crystal phase is a beta-spodumene solid solution, which exhibit coefficients of thermal expansion (25.degree.-700.degree. C.) less than about 15 .times. 10.sup.-7 /.degree. C. and, preferably, less than 10 .times. 10.sup.-7 /.degree. C., and wherein transmittances to infra-red radiations as great as 60% have been measured at a wavelength of 3.5 microns in samples having thicknesses of about 4.25 mm. Such articles have compositions circumscribed within a narrow field of the Li.sub.2 O--Al.sub.2 O.sub.3 --SiO.sub.2 system nucleated with TiO.sub.2 which contain ZnO as the principal modifier ion and are essentially free from the alkaline earth metal oxides, alkali metal oxides other than Li.sub.2 O, and ZrO.sub.2.

Abstract: The instant invention is concerned with a unique method for crystallizing glass bodies into glass-ceramic articles. More particularly, this invention is drawn to a method whereby glass-ceramic articles can be formed without cooling the precursor glass below the transformation range thereof. Thus, the glass melt is cooled and formed into a vitreous body. This vitreous body is cooled to a temperature no lower than about 25.degree.-250.degree. C. above the transformation range where nucleation is developed therewithin. Essentially immediately thereafter, the nucleated body is exposed to a temperature between about 100.degree.-500.degree. C. higher than that of the nucleation step to cause the growth of crystals on the nuclei. The process significantly expedites the production of glass-ceramic articles and substantially reduces energy consumption from the forming stage to the finished product.

Abstract: Suitable glass-ceramic base compositions, including some silicates, aluminosilicates, lithium aluminosilicates, and boroaluminates, are modified by the addition of suitable quantities of transition metal oxides prior to melting and forming into thermally-crystallizable glass articles. Appropriate crystallization and post-crystallization heat treatments are thereafter employed to cause crystallization of the articles and the formation and growth of films thereon, which films are characterized by the presence of transition metal compounds, typically of spinel structure, therein. Such films demonstrate useful electrical, magnetic, catalytic and/or light-absorptive properties.

Abstract: The instant invention relates to the production of highly-crystalline, transparent glass-ceramic articles wherein the predominant crystal phase is a beta-quartz solid solution and which demonstrate transmittances of infra-red radiations up to about 80% at a wavelength of 3.5 microns in bodies having thickness dimensions of about 4 mm. The articles of the invention have compositions within a very narrow area of the Li.sub.2 O--Al.sub.2 O.sub.3 --SiO.sub.2 field, nucleated with TiO.sub.2, and wherein some of the silica is replaced with AlPO.sub.4. Minor additions of ZrO.sub.2 enhance the chemical durability of the articles and, if desired, coloring agents can be added to yield colored, transparent, crystalline articles.

Abstract: This invention relates to the production of vitreous fibrous materials exhibiting excellent resistance to alkaline attack. More particularly, the instant invention is directed to the production of fibers consisting essentially of basalt and zirconia which demonstrate such exceptional resistance to attack from the basic components present in such calcareous cementitious materials as portland cement as to render them especially useful as reinforcing elements in cementitious materials.

Abstract: The instant invention relates to the manufacture of articles demonstrating the physical properties and internal microstructure of glass-ceramic bodies but which can be formed spontaneously from molten glass. Thus, the heat treatment of a precursor glass body, such as is required in the production of conventional glass-ceramic articles to cause the crystallization in situ thereof, is avoided. More particularly, this invention relates to the manufacture of highly crystalline glass-ceramic articles having compositions within the Na.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 field, wherein carnegieite and/or nepheline solid solution crystals constitute the predominant crystal phase, which can be formed spontaneously from a molten glass batch.

Abstract: The present invention is concerned with the production of articles having the physical properties and internal microstructure normally associated with glass-ceramic articles, but which can be formed spontaneously from a molten glass batch. Hence, the instant invention avoids the heat treatment of a precursor glass body, such as is required in the manufacture of conventional glass-ceramic bodies to cause the crystallization in situ thereof. More specifically, this invention relates to the production of highly-crystalline glass-ceramic articles having compositions within the BaO and/or SrO-Fe.sub.2 O.sub.3 -SiO.sub.2 field, wherein BaO and/or SrO-Fe.sub.2 O.sub.3 -SiO.sub.2 solid solution crystals comprise the predominant crystal phase, which can be formed spontaneously from a molten glass batch.

Abstract: Suitable glass-ceramic base compositions, including some siicates, aluminosilicates, lithium aluminosilicates, and boroaluminates, are modified by the addition of suitable quantities of transition metal oxides prior to melting and forming into thermallycrystallizable glass articles. Appropriate crystallization and post-crystallization heat treatments are thereafter employed to cause crystallization of the articles and the formation and growth of films thereon, which films are characterized by the presence of transition metal compounds of spinel structure therein. Such films demonstrate useful electrical, magnetic, catalytic and/or light-absorptive properties.