Abstract: Porous, silica-rich shapes have improved strength and abrasion resistance by leaching the precursor glass shape in preconditioned acid having silica ion and at least one common ion that is also present in the precursor glass shape. The precursor glass shapes have shapes such as fibers, hollow fibers, tubes, rods, beads, hollow spheres and plates and compositions having 30-75 volume percent silica and at least 10-65 volume percent nonsiliceous acid extractable components. Preconditioning of the acid solution results from a pretreatment of the acid with compounds that dissociate into the ions when added to the acid solution or with shapes, particles or fragments of glass compositions different from or similar to the glass shape to be leached so long as the glass composition has extractable material to provide the silica ion and at least one common ion.

Abstract: A sol-gel method for making gradient-index glass and a novel composition therefor, comprising at least a ternary system of metal alkoxides.

Abstract: A particulate porous material suitable for use as a high surface area column packing material comprises particles substantially all of which are not smaller than 5 micrometers and not larger than 1 millimeter in diameter, and each particle is in the form of a substantially cellular body and consists predominantly of an open, three-dimensional matrix of crystals of mullite which define between them interconnecting pores having a width in the range of from 5 nanometers to about 2 micrometers. The particles can be coated with a reactive layer. There is also disclosed a process for producing the particulate porous material wherein a particulate product comprising particles substantially all of which are between 5 micrometers and 1 millimeter in diameter and consisting predominantly of a mixture of mullite crystals and silica is treated with a concentrated aqueous solution of an alkali metal hydroxide at a temperature of at least 50.degree. C.

Abstract: A particulate porous material suitable for use as a high surface area column packing material comprises particles substantially all of which are not smaller than 5 micrometers and not larger than 1 millimeter in diameter, and each particle is in the form of a substantially cellular body and consists predominantly of an open, three-dimensional matrix of crystals of mullite which define between them interconnecting pores having a width in the range of from 5 nanometers to about 2 micrometers. The particles can be coated with a reactive layer. There is also disclosed a process for producing the particulate porous material wherein a particulate product comprising particles substantially all of which are between 5 micrometers and 1 millimeter in diameter and consisting predominantly of a mixture of mullite crystals and silica is treated with a concentrated aqueous solution of an alkali metal hydroxide at a temperature of at least 50.degree. C.

Abstract: There is disclosed a lithium aluminosilicate glass body encased within, and integral with, a thin, compressive, semicrystalline layer containing beta-eucryptite and/or beta-quartz solid solution crystals, and a method of producing such body. The layer has a substantially lower thermal coefficient of expansion than the glass, but has the same chemical composition as the glass. That composition, in percent by weight on a calculated oxide basis is 55-67% SiO.sub.2, 5.0-7.5% Li.sub.2 O, 22-28% Al.sub.2 O.sub.3, 0-2% Na.sub.2 O and 0-10% ZnO, the molar ratio of R.sub.2 O+RO to Al.sub.2 O.sub.3 being greater than one. Controlled crystallization procedure is described whereby the crystallized layer can be produced in a relatively short time.

Abstract: This specification discloses optical light-weight glass having a composition of SiO.sub.2 47--70, Li.sub.2 O 5.5-21, K.sub.2 O 2-30, Na.sub.2 O 0-30 (Li.sub.2 O+Na.sub.2 O+K.sub.2 O 21-50), TiO.sub.2 9.5-24, B.sub.2 O.sub.3 0-20, CaO 0-20, MgO+SrO+BaO+ZnO 0-4, Al.sub.2 O.sub.3 0-5 and ZrO.sub.2 +La.sub.2 O.sub.3 +Ta.sub.2 O.sub.5 +WO.sub.3 0-3, all being in % by weight, and having a refractive index (n.sub.d) of 1.58-1.65, an Abbe number (.gamma..sub.d) of 35-50 and a specific gravity of 2.69 or less. This optical glass is light in weight, high in transparency and low in dispersion, and is particularly suitable for spectacle lenses, but can also be utilized for photographic lenses.

Abstract: A sol-gel method for making gradient-index glass and a novel composition therefor, comprising at least a ternary system of metal alkoxides.

Abstract: A radioactive microsphere for radiation therapy of a mammal comprising a biologically compatible glass material containing a beta or gamma emitting radioisotope distributed substantially uniformly throughout the glass. Advantageously, the radioisotope is produced by irradiation of the microsphere.

Abstract: A duplex glass preform for forming hermetic glass-to-metal seals of the compression type. The duplex glass preform comprises a glass infrasturcture or matrix having at least one end thereof modified by the selective distribution therein of ceramic particles. The ceramic particles are selectively distributed to form a ceramic density gradient having the largest concentration of ceramic particles at the surface and gradually decreasing with depth. The duplex glass preform of the present invention has utility in forming glass-to-metal compression seals in hybrid metal packages containing microcircuit chips. The duplex glass preform may be used in the normal insulative fashion or as a conductive member.

Abstract: A fluoroaluminosilicate glass powder for dental glass ionomer cement, a surface of which is treated with a fluoride in an amount of from 0.01 to 5 parts by weight based on 100 parts by weight of the glass powder, is disclosed. The fluoroaluminosilicate glass powder of the invention is improved in not only physical properties such as crushing strength but also mixing workability without impairing the inherent characteristics thereof for the dental use.

Abstract: Optical glasses based on silica and alumina, rich in modifying metals such as silver, thallium and cesium. The exchange by cathodic migration in a melted salt bath of said modifying metals by metals such as K, Na and Li, exchange which leads to a corresponding variation of the refraction index of the glass according to a certain predetermined profile, is performed very efficiently and rapidly. Such an exchange is performed either on the finished glass or on a microporous form thereof.

Abstract: A glass composition is disclosed which is formed from a mixture comprising one or a plurality of natural mineral zeolites and having a melting point in the range of from about 1000.degree. to about 1500.degree. C. The glass compositions of this invention can be formed into various glass articles, including flat glass, glass containers, glass fiber and glass foam.

Abstract: Suspensions of particulate oxides, e.g., fumed silica, are prepared in non-aqueous media and the suspensions are used to cast shapes for glass or ceramic products. The suspensions are formed and then caused to gel by means of an added gelling agent, and thereafter dried and, optionally, sintered to transparent glass or void-free ceramic products.

Abstract: A composition for forming a high temperature, acid and alkali resistant refractory fiber. The compositional formulation, by weight, is 56-76% silica, 12-33% alumina, and 3-22% zirconia. These fibers are chemically resistant in both acidic and alkaline environments even when heat treated to temperatures exceeding 500.degree. F. (260.degree. C.) in such environments.

Abstract: A composition for forming a high temperature, alkali resistant refractory fiber. The compositional formulation, by weight, is 46-52% silica, 32-38% alumina, 13-18% zirconia with a silica to zirconia ratio in the range from 2.6 to 3.8. These fibers have a maximum service temperature in the range of 2550.degree. F. (1400.degree. C.) to 2650.degree. F. (1455.degree. C.) and exhibit better shrinkage resistance than similarly rated commercially available refractory fiber.

Abstract: This invention is related to the production of machinable glass-ceramic articles which are essentially free from crystals having a mica structure and consist essentially, in weight percent, ofSiO.sub.2 : 24-28Al.sub.2 O.sub.3 : 9-20MgO: 12-28SrO: 0-11BaO: 0-14CuO: 0-5Ag.sub.2 O: 0-3.5NiO: 0-1.5Cr.sub.2 O.sub.3 : 0.5-6.

Abstract: A mixture containing 35 to 65% by weight of Al.sub.2 O.sub.3, 30 to 60% by weight of SiO.sub.2, 1.5 to 4% by weight of Cr.sub.2 O.sub.3, and 0.01 to 0.1% by weight of carbon, the balance being unavoidable impurities, is melted, and amorphous fibers are formed from said molten material by blowing or spinning. The fibers are heated rapidly to a temperature of 950.degree. C. to 1,150.degree. C., held at that temperature for several to about a dozen minutes, and cooled rapidly to ordinary room temperature.

Abstract: Quartz glass includes iron and aluminum. The total iron content ranges from 0.01 to 5% by weight, and the total aluminum content ranges from 0.01 to 10% by weight. The quartz glass exhibits infrared rays-absorbing ability and visible light-transmitting ability. Also a process for making such a quartz glass is disclosed.

Abstract: A thallium-containing optical glass composition which contains the following oxides in the indicated proportions in mole %:______________________________________ SiO.sub.2 35-80 Tl.sub.2 O 4-26 Tl.sub.2 O + R.sub.2 O 8-42 (in which R is an alkali metal) ZnO 6-26 ZrO.sub.2 0-2 Al.sub.2 O.sub.3 0-8 SnO and/or SnO.sub.2 0-5 B.sub.2 O.sub.3 0-less than 10 ______________________________________and satisfies the following relations:O.ltoreq.K.sub.2 O.ltoreq.104.ltoreq.Na.sub.2 O+Li.sub.2 O.ltoreq.260.1.ltoreq.ZrO.sub.2 +Al.sub.2 O.sub.3 +SnO and/or SnO.sub.2 .ltoreq.

Abstract: A thallium-containing optical glass composition which comprises the following oxides in the indicated proportions in mole %: SiO.sub.2 35-80, Tl.sub.2 O 1-30, Tl.sub.2 O+R.sub.2 O (R being an alkali metal) 1-35, ZnO 0-35, GeO.sub.2 0-30, BaO 0-25, TiO.sub.2 0-20, MgO 0-20, B.sub.2 O.sub.3 0-less than 10, ZrO.sub.2 0-2, Al.sub.2 O.sub.3 0-8, SnO 0-5, CaO 0-10, SrO 0-10, PbO 0-10, La.sub.2 O.sub.3 0-5, Bi.sub.2 O.sub.3 0-8, and Ta.sub.2 O.sub.5 0-2, and satisfies the following relations:5.ltoreq.ZnO+GeO.sub.2 +BaO+TiO.sub.2 +MgO+B.sub.2 O.sub.3 .ltoreq.40,0.1.ltoreq.ZrO.sub.2 +Al.sub.2 O.sub.3 +SnO.ltoreq.8,and0.ltoreq.CaO+SrO+PbO+La.sub.2 O.sub.3 +Bi.sub.2 O.sub.3 +Ta.sub.2 O.sub.5 .ltoreq.10.

Abstract: What is disclosed is a method of preparing carbon-containing monolithic glassy ceramics from organosilsesquioxanes, metal oxides and metal alkoxides through pyrolysis of their gels. Also disclosed are certain gel compositions used in the method and the glassy ceramics.

Abstract: An ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A.sub.1+x D.sub.2-x/3 Si.sub.x P.sub.3-x O.sub.12-2x/3, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

Abstract: This invention is directed to the production of transparent, translucent, and opaque glass-ceramic articles containing .beta.-quartz solid solution as the predominant crystal phase exhibiting colors ranging from black to brown to red, and opaque glass-ceramic articles containing .beta.-spodumene solid solution as the predominant crystal phase exhibiting colors ranging from gray to brown to almond to beige to yellow to blue. Both types of articles can be prepared by heat treating precursor glass articles essentially free from MgO and consisting essentially, in weight percent, of:______________________________________ SiO.sub.2 63.5-69 BaO 0-5 Al.sub.2 O.sub.3 15-25 TiO.sub.2 >2.5-6 Li.sub.2 O 2.5-4 ZrO.sub.2 0-2 Na.sub.2 O 0.1-0.6 As.sub.2 O.sub.3 0.4-0.8 K.sub.2 O 0.1-0.6 Fe.sub.2 O.sub.3 0.05-0.2 ZnO 0-2 ______________________________________and 0.3-3% total of at least two oxides in the indicated proportions selected from the group of 0-2% CaO, 0-3% CeO.sub.2, 0-1% NiO, 0-1.5% SnO.sub.2, 0-0.3% V.sub.

Abstract: The present invention is concerned with the preparation of hydraulic cements, demonstrating high mechanical strength, long term resistance to attack by moisture, and virtual freedom from creep, from glass powders consisting essentially, expressed in terms of mole percent on the oxide basis, of about 60-76% SiO.sub.2, 15-30% K.sub.2 O, and 2-15% total of at least one metal oxide selected from the group of 0-10% Al.sub.2 O.sub.3, 0-5% V.sub.2 O.sub.5, 0-5% TiO.sub.2, 0-5% MoO.sub.3 and 0-5% WO.sub.3. The cements exhibit particular utility in forming strong cellular ceramic articles. The glass powders may contain a phosphate component in which case the composition ranges are limited to 68-76% SiO.sub.2, 18-24% K.sub.2 O, 2-4.5% P.sub.2 O.sub.5 with the molar ratio K.sub.2 O:P.sub.2 O.sub.5 ranging between 5 and 10, and 2-5% total of at least one metal oxide selected from the group of Al.sub.2 O.sub.3, MoO.sub.3, V.sub.2 O.sub.5 and WO.sub.3.

Abstract: Foamable glass composition suitable for making glass foam, which starts from water glass material and consisting essentially of 100 parts by weight of anhydrous modified sodium silicate and 0.5-4 parts by weight of CaCO.sub.3 as a foaming agent. A foam in the closed-cell form, which is light is in weight, and excellent water resistance, strength and heat resistance, is obtained, wherein CO.sub.2 in a gas existing in the cell is 50% by volume or more.

Abstract: Soda-lime glass contains by weight the following glass forming oxides:______________________________________ SiO.sub.2 60 to 75% Na.sub.2 O 10 to 20% CaO 0 to 16% K.sub.2 O 0 to 10% MgO 0 to 10% Al.sub.2 O.sub.3 0 to 5% BaO 0 to 2% BaO + CaO + MgO 10 to 20% K.sub.2 O + Na.sub.2 O 10 to 20% ______________________________________In order to produce a tinted glass having favorable properties as regards its cost, color and freedom from haze, the following coloring agents (proportions by weight) are incorporated in the glass: ______________________________________ Fe.sub.2 O.sub.3 0.3 to 0.5% Cr.sub.2 O.sub.3 0.0075 to 0.0230% Se 0.0005 to 0.0019% Co 0.0040 to 0.0070% Ni 0.0050 to 0.

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: Silicon carbide fiber reinforced glass composites are disclosed having high strength, fracture toughness, and oxidative stability, even in high temperature use environments. Disclosed composites include silicon carbide fiber reinforced borosilicate glass, high silica content glass, and aluminosilicate glass. Flexural strengths in excess of 40,000 psi up to temperatures as high as 1150.degree. C. are attained with such composites.

Abstract: What is disclosed is a method of preparing carbon-containing monolithic glassy ceramics from organosilsesquioxanes, metal oxides and metal alkoxides through pyrolysis of their gels. Also disclosed are certain gel compositions used in the method and the glassy ceramics.