Abstract:
This invention relates to the production of hard, high-modulus glass-ceramic articles having compositions within the MgO-Al2O3B2O3-SiO2 field nucleated with a combination of TiO2 and ZrO2 wherein the principal crystal phases are alpha-quartz and sapphirine. Where such articles are contacted with a source of lithium ions at elevated temperatures, an exchange of lithium ions for magnesium ions on a two-Li -for-one Mg 2basis takes place within the crystal structures resulting in the development of a surface layer wherein the primary crystal phase is a lithium-stuffed beta-quartz solid solution, also sometimes termed beta-eucryptite solid solution. This phenomenon causes the development of compressive stresses within the ion exchanged surface layer as the articles are cooled below the exchange temperature leading to a marked improvement in the mechanical strength of the articles.
Abstract translation:本发明涉及具有在TiO 2和ZrO 2的组合中形成的MgO-Al 2 O 3 -B 2 O 3 -SiO 2场中的组成的硬质高模量玻璃陶瓷制品,其中主晶相是α-石英和蓝宝石。 当这些物品在升高的温度下与锂离子源接触时,在晶体结构内发生基于二Li +一Mg 2+的镁离子的锂离子交换,导致 表面层的开发,其中初晶相是锂填充的β-石英固溶体,有时也被称为β-锂辉石固溶体。 当物品被冷却到交换温度以下时,这种现象导致离子交换表面层内的压应力的发展,导致制品的机械强度显着提高。
Abstract:
THIS INVENTION RELATES TO THE MANUFACTURE OF GLASSCERAMIC ARTICLES, WHEREIN MAGNETITE CRYSTALS ALONE OR IN COMBINATION WITH CLINOPYROXENE CRYSTALS CONSTITUTE SUBSTANTIALLY ALL OF THE CRYSTALS PRESENT, BY MELTING NATURALLYOCCURRING BASALTS UNDER OXIDIZING CONDITIONS, COOLING THE MOLTEN BASALT TO A GLASS, AND THEN HEAT TREATING THE GLASS UNDER NON-REDUCING CONDITIONS TO C RYSTALLIZE IN SITU UNIFORMLY FINE-GRAINED CRYSTALS OF MAGNETITE WITH OR WITHOUT CLINOPYROXENE HOMOGENEOUSLY DISPERSED IN A GLASSY MATRIX.
Abstract:
THIS INVENTION RELATES TO THE PRODUCTION OF FLUORINE MICA GLASS-CERAMIC ARTICLES FROM GLASS ARTICLES IN THE COMPOSITION SYSTEM SIO2-B2O3-AL2O3-MGO-K2O-F WHICH ARE ABOUT 50-90% BY VOLUME CRYSTALLINE, THE CRYSTALS BEING RELATED IN STRUCTURE AND COMPOSITION TO THE NATURAL MINERAL PHLOGOPITE. THESE MICA GLASS-CERAMIC PRODUCTS EXHIBIT GOOD MACHINEABILITY WITH STEEL TOOLS, GOOD MECHANICAL STRENGTH AND IMPACT RESISTANCE, EXCELLENT THERMAL SHOCK RESISTANCE, AND SUPERIOR DIELECTRIC PROPERTIES.
Abstract:
THIS INVENTION RELATES TO THE MANUFACTURE OF GLASSCERAMIC ARTICLES EXHIBITING VERY LOW COEFFICIENTS OF THERMAL EXPANSION WHICH HAVE COMPOSITIONS IN THE ZN0-AL2O3SIO2 FIELD. THE ESSENTIAL ABSENCE OF ALKALI METAL IN THE COMPOSITIONS ENDOWS THE PRODUCTS OF THIS INVENTION WITH HIGH ELECTRICAL RESISTIVITY.
Abstract:
Compositions comprising sodium oxide and optionally other alkali metal oxides, a glass network-forming oxide such as SiO2 or GeO2, a modifying oxide such as Al2O3 or Ga2O3, a halogen such as Cl or F, and an electron donor constituent such as sulfur, selenium or tellurium, are melted to form glasses which may be reversibly photochromic, and are thermally crystallized to form glassceramics comprising sodalite or analogous crystal phases which are also reversibly photochromic. The glasses and glass-ceramics may also exhibit induced fluorescence in the activated (darkened) state.
Abstract translation:包含氧化钠和任选的其它碱金属氧化物的组合物,诸如SiO 2或GeO 2的玻璃网络形成氧化物,诸如Al 2 O 3或Ga 2 O 3的改性氧化物,诸如Cl或F的卤素,以及诸如硫,硒的电子给体成分 或碲被熔化以形成可逆的光致变色的玻璃,并且被热结晶以形成也可逆的光致变色的包含方钠石或类似晶相的玻璃陶瓷。 玻璃和玻璃陶瓷也可能在活化(变暗)状态下表现出诱导荧光。
Abstract:
THIS INVENTION RELATES TO THE PRODUCTION OF A DEVITRIFIABLE GLASS FRIT HAVING A COMPOSITION WITHIN THE LI2OAL2O3-SIO2 FIELD WHICH EXHIBITS, AFTER DEVITRIFICATION, A COEFFICIENT OF THERMAL EXPANSION (0*-1000* C.) OF LESS THAN 15X10-7/* C. AND EXCELLENT DIMENSIONAL STABILITY WHEN SUBJECTED FOR LONG PERIODS OF TIME AT TEMPERATURES UP TO 900*C. SUCH A FRIT IS ESPECIALY SUITABLE FOR THE MANUFACTURE OF REGENERATIVE HEAT EXCHANGER BODIES FOR USE WITH GAS TURBINES.
Abstract:
THIS INVENTION RELATES TO THE MANUFACTURE OF GLASSCERAMIC ARTICLES IN THE RO-AL2O3-SIO2 COMPOSITION FIELD WHEREIN RO CONSISTS OF MGO AND/OR CAO AND WHEREIN WO3 AND, OPTIONALLY, MOO3 ACT AS NUCLEATING AGENTS. MULLITE, MGWO4, CAWO4, MGMOO4, CA-MOO4 AND AN AS YET UNIDENTIFIED SILICATE CRYSTAL CONSTITUTE THE PRINCIPAL CRYSTAL PHASES.
Abstract:
This invention relates to the development of strong, highly porous glass-ceramic bodies exhibiting extremely high surface areas such as to render them eminently suitable for catalyst supports designed for use in emissions control systems utilized in combination with internal combustion engines. These bodies are manufactured through a leaching process which provides a surface layer or an entire bulk having a relatively homogeneous porosity with very high surface area wherein the size of the pores can be controlled to a reasonable uniformity.
Abstract:
THIS INVENTION RELATES TO THE STRENGTHENING OF GLASSCERAMIC ARTICLES THROUGH AN ION EXCHANGE PROCESS WHEREIN THE STRENGTH IS RETAINED WHEN THE ARTICLES ARE USED IN SERVICE APPLICATIONS AT HIGH TEMPERATURES. MORE PARTICULARLY, THIS INVENTION RELATES TO THE STRENGTHENING OF GLASSCERAMIC ARTICLES CONTAINING STUFFED BETA-QUARTZ AS THE PRINCIPAL CRYSTAL PHASE THROUGH THE EXCHANGE OF LITHIUM IONS FOR ALUMINUM IONS IN THE SURFACE OF SUCH ARTICLES AT A TEMPERATURE OF AT LEAST ABOUT 900*C.