Abstract: The glass-ceramic disclosed is characterized by a lithium aluminosilicate crystal phase having a very low coefficient of thermal expansion and a residual glassy phase of substantial amount and higher coefficient of expansion, usually a borosilicate or boroaluminosilicate glass. The two phases form a dilatant system wherein the thermal expansion curve changes markedly in character at a transition point in the range of 500.degree.-750.degree. C., the crystal phase dominating below that temperature and the glass phase controlling at higher temperatures.

Abstract: The instant invention is directed to the production of highly crystalline glass-ceramic articles demonstrating high intrinsic mechanical strength and toughness containing crystals of canasite and/or agrellite and/or fedorite as the predominant crystal phase. The articles have overall compositions consisting essentially, expressed in terms of weight percent on the oxide basis, of about______________________________________ SiO.sub.2 45-75 CaO 8-30 F 3.5-12 Na.sub.2 O 3-15 K.sub.2 O 0-20 Na.sub.2 O + K.sub.2 O 5-25 B.sub.2 O.sub.3 0-6 Al.sub.2 O.sub.3 0-7 ZrO.sub.

Abstract: The present invention is concerned with glass-ceramic articles which are extremely resistant to impact and spontaneous delayed breakage, are capable of being sawn with a diamond wheel to a depth of over one-third the cross section thereof without breakage, and exhibit modulus of rupture values of at last 150,000 psi. The articles consist of a body portion and an integral surface compression layer having a depth of at least 0.005". The body portion consists essentially, in weight percent, of about 8-13% Na.sub.2 O, 7-13% K.sub.2 O, 30-36% Al.sub.2 O.sub.3, 35-43% SiO.sub.2, and 6-10% RO.sub.2, wherein RO.sub.2 consists of 6-10% TiO.sub.2 and 0-4% ZrO.sub.2, wherein the molar ratio Al.sub.2 O.sub.3 :SiO.sub.2 is >0.5 but <0.6 and the molar ratio K.sub.2 O:Na.sub.2 O is >1:3 but <1 and contains nepheline solid solution crystals corresponding to the formula Na.sub.8-x K.sub.x Al.sub.8 Si.sub.8 O.sub.32, with x varying from 0.25-4.73, as the predominant crystal phase.

Abstract: The present invention is related to the production of crystal-containing gels and papers, films, fibers, boards, and coatings made therefrom. The process for making the gels comprises three general steps: first, a fully or predominantly crystalline body is formed containing crystals consisting essentially of a lithium and/or sodium water-swelling mica selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structures selected from the group of talc, fluortalc, polylithionite, fluorpolylithionite, phlogopite, and fluorphlogopite; second, that body is contacted with a polar liquid, desirably water, to cause swelling and disintegration of the body accompanied with the formation of a gel; and, third, the solid:liquid ratio of the gel is adjusted to a desired value depending upon the application therefor.

Abstract: Polychromatic glass articles and methods of producing such articles are disclosed in which the glass is activated by exposure to ultraviolet radiation and contains as a sensitizing agent an oxide of copper, samarium, terbium, praeseodymium, or europium.

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: The present invention is concerned with glass-ceramic articles which are extremely resistant to impact and spontaneous delayed breakage, are capable of being sawn with a diamond wheel to a depth of over one-third the cross section thereof without breakage, and exhibit modulus of rupture values of at least 150,000 psi. The articles consist of a body portion and an integral surface compression layer having a depth of at least 0.005". The body portion consists essentially, in weight percent, of about 8-13% Na.sub.2 O, 7-13% K.sub.2 O, 30-36% Al.sub.2 O.sub.3, 35-43% SiO.sub.2, and 6-10% RO.sub.2, wherein RO.sub.2 consists of 6-10% TiO.sub.2 and 0-4% ZrO.sub.2, wherein the molar ratio Al.sub.2 O.sub.3 :SiO.sub.2 is >0.5 but <0.6 and the molar ratio K.sub.2 O:Na.sub.2 O is >1:3 but <1 and contains nepheline solid solution crystals corresponding to the formula Na.sub.8-x K.sub.x Al.sub.8 Si.sub.8 O.sub.32, with x varying from 0.25-4.73, as the predominant crystal phase.

Abstract: A polychromatic glass article, colored by silver, is disclosed wherein the silver occurs as an anisotropic film at the surface of lithium bromide spherulites which crystallize directly on silver nuclei from lithium silicate and lithium aluminosilicate glasses. The article is produced by sequential radiation exposures and heat treatments of the glass.

Abstract: The present invention is related to the production of crystal-containing gels and papers, films, fibers, boards, and coatings made therefrom. The process for making the gels comprises three general steps: first, a fully or predominantly crystalline body is formed containing crystals consisting essentially of a lithium and/or sodium water-swelling mica selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structurally-compatible species selected from the group of talc, fluortalc, polylithionite, fluorpolylithionite, phlogopite, and fluorphlogopite; second, that body is contacted with a polar liquid, desirably water, to cause swelling and disintegration of the body accompanied with the formation of a gel; and, third, the solid:liquid ratio of the gel is adjusted to a desired value depending upon the application therefor.

Abstract: The instant invention to the manufacture of articles exhibiting the highly-crystalline, uniformly fine-grained microstructure of conventional glass-ceramic bodies, but which can be formed spontaneously through cooling a molten glass-forming batch. Hence, the articles of the present invention are not produced by heat treating glass bodies at elevated temperatures to cause crystallization in situ as is required in the manufacture of the classic glass-ceramic articles. Instead, this invention provides a method for spontaneously-forming glass-ceramic articles having compositions within a narrowly-defined area of the Li.sub.2 O-Al.sub.2 O.sub.3 -B.sub.2 O.sub.3 -SiO.sub.2 -TiO.sub.2 field wherein alpha-quartz solid solution constitutes the predominant crystal phase.

Abstract: The present invention is related to the production of crystal-containing gels and papers, films, fibers, boards, and coatings made therefrom. The process for making the gels comprises three general steps: first, a fully or predominantly crystalline body is formed containing crystals consisting essentially of a lithium and/or sodium water-swelling mica selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structurally-compatible species selected from the group of talc, fluortalc, polylithionite, fluorpolylithionite, phlogopite and fluorphlogopite; second, that body is contacted with a polar liquid, desirably water, to cause swelling and disintegration of the body accompanied with the formation of a gel; and, third, the solid:liquid ratio of the gel is adjusted to a desired value depending upon the application therefor.

Abstract: The present invention provides a method for making porous bodies of magnetic glass and/or crystal-containing materials having magnetic crystals incorporated therein with dimensions less than about 1000A. Preferably, the crystals have dimensions less than 500A such that the porous bodies demonstrate essential superparamagnetic behavior. The method involves preparing a body which, upon heat treatment, will separate into at least two vitreous phases and at least one crystal phase. One of the vitreous phases is etched away leaving a structure remaining which contains said magnetic crystals. When present as fine particles, the porous magnetic bodies are especially suitable for use in biological assays.

Abstract: The present invention relates to the preparation of essentially silica-free glasses which can be melted at low temperatures and which have compositions within the Li.sub.2 O--Al.sub.2 O.sub.3 and/or F--B.sub.2 O.sub.3 system. The glasses exhibit very high lithium ion mobility which, resulting in low electrical resistivity, has led to their consideration as solid membrane electrolyte-separators in such devices as the lithium metal-sulfur battery.

Abstract: The instant invention relates to the production of glass and glass-ceramic compositions containing a ferrimagnetic crystal phase throughout which respond thermally to fields generated by induction coils. Magnetite (Fe.sub.3 O.sub.4) is the preferred ferrimagnetic crystal phase because of its high permeability and low resistivity (.about.10.sup.-4 ohm-cm) at room temperature as well as the relative low cost of iron when compared with other ferrimagnetic species. Two general composition areas are of interest: Na.sub.2 O and/or K.sub.2 O-FeO-B.sub.2 O.sub.3 -SiO.sub.2 and Li.sub.2 O-Al.sub.2 O.sub.3 -B.sub.2 O.sub.3 -SiO.sub.2. Where the coefficient of thermal expansion is sufficiently low to impart good thermal shock resistance, the compositions can be considered for top-of-stove cooking vessels.

Abstract: The instant invention is related to the production of glass-ceramic articles which exhibit a hydrophobic character and an inherent tactile quality of being slippery or oily to the touch. Such articles are dervived from compositions within the MgO--Al.sub.2 O.sub.3 --SiO.sub.2 --F quaternary and contain the humite mineral norbergite (Mg.sub.2 SiO.sub.4. MgF.sub.2) as a major crystal phase. The intrinsic hydrophobic character and lubricity of the inventive compositions recommend their utility in such applications as (1) high temperature bearing or other low friction mechanical devices, an (2) non-sticking and easily-cleaned culinary ware.

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 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: This invention is concerned with the production of glass-ceramic articles wherein phlogopite mica solid solution and beta-spodumene solid solution comprise the primary crystal phases. Such articles demonstrate good machineability characteristics along with low coefficients of thermal expansion, excellent thermal shock resistance, and relatively high refractoriness.

Abstract: This invention is concerned with glass-ceramic articles having compositions within a very narrowly-delimited area of the MgO-Al.sub.2 O.sub.3 -B.sub.2 O.sub.3 -SiO.sub.2 field and having alpha-quartz and sapphirine as the principal crystal phases, resulting from nucleation through a combination of TiO.sub.2 and ZrO.sub.2. Upon contacting such articles with lithium ions at an elevated temperature, said lithium ions will replace magnesium ions on a two Li.sup.+-for-one Mg.sup..sup.+2 basis within the crystal structures, thereby providing a unitary glass-ceramic article having an integral surface layer wherein the principal crystal phase is a lithium-stuffed beta-quartz solid solution. That transformation of crystal phases results in compressive stresses being set up within the surface layer as the articles are cooled.

Abstract: A strengthened glass-ceramic laminated article having a compressively-stressed surface layer substantially enveloping a tensilely-stressed core portion, produced by choosing the core and surface layer compositions such that the core undergoes a net positive differential densification with respect to the surface layer as the result of phase transformations occurring in the laminated article during crystallization in situ. Such an article offers significant advantages over glass and glass-ceramic articles strengthened by prior art methods, including improved mechanical stability, thermal shock resistance, and, most importantly, excellent high temperature strength retention.