Abstract: A phosphate glass ceramic which can be utilized especially as biomaterial in medicine and biology. The object of the invention is to provide a glass ceramic extensively adapted to bone, possessing adjustable biologically active characteristics. Another object of the invention is to produce a glass ceramic free of SiO.sub.2 or low in SiO.sub.2, of high P.sub.2 O.sub.5 and CaO content, possessing adjustable biologically active characteristics. The object is solved, whereby an initial glass of the composition having the mass percentages of Al.sub.2 O.sub.3 3-21, CaO 8-26, R.sub.2 O 10-25, P.sub.2 O.sub.5 43-58, is provided under the condition that R.sub.2 O can contain up to 25% of mass of Na.sub.2 O and up to 18% of mass of K.sub.2 O, and is thermally treated after melting, to provide the new phosphate glass ceramic. The main crystal phases are apatite and aluminiumorthophosphate. The phosphate glass ceramic can contain additions of SiO.sub.2, B.sub.2 O.sub.3, F.sup.-, MgO, FeO, Fe.sub.2 O.sub.3, TiO.sub.2.

Abstract: This invention relates to the production of highly transparent glass-ceramic articles containing about 30-50% by volume gahnite having dimensions finer than about 300 .ANG. as essentially the sole crystal phase. The articles have compositions essentially free of Li.sub.2 O, Na.sub.2 O, CaO, SrO, and BaO and consist essentially, by weight, of about 1.5-5% R.sub.2 O, consisting of 0-3% K.sub.2 O and/or 0-3% Rb.sub.2 O and/or 0-3% Cs.sub.2 O, 13-22% ZnO, 16-28% Al.sub.2 O.sub.3, 45-65% SiO.sub.2, and 1.5-8% TiO.sub.2.

Abstract: Calcium phosphate glass-ceramics of high strength and toughness is disclosed. These materials are excellent for artificial dental or bone materials. The strength and toughness of these materials are improved substantially in comparison with conventionally used calcium phosphate glass-ceramics by adding rare earth oxide in them. For dental materials, good aesthetic appearance to natural teeth is also obtained by adding one type, or two or more types of compounds selected from oxides of iron, manganese, cerium, titanium, nickel, zinc, cobalt, tungsten, chromium, and vanadium as color component. Also, if necessary, Al.sub.2 O.sub.3 and/or SiO.sub.2 is contained as coloring assistant agent in that composite. Moreover it is possible to adjust the color tone of each individual's teeth. The rare earth oxide, coloring component, and coloring assistant agent added are incorporated in crystals of calcium phosphate. Consequently, they cause no elution during use.

Abstract: The present invention is concerned with the preparation of glass microfoams and gas-ceramics having compositions selected from the systems of SiO.sub.2 --Al.sub.2 O.sub.3 --B.sub.2 O.sub.3 --RO--R.sub.2 O, SiO.sub.2 --Al.sub.2 O.sub.3 (B.sub.2 O.sub.3)--P.sub.2 O.sub.5 --Li.sub.2 O--[ZrO.sub.2 (TiO.sub.2)], and SiO.sub.2 --P.sub.2 O.sub.5 --B.sub.2 O.sub.3 --[RO], wherein RO is selected from the group of MgO, CaO, SrO, BaO, and ZnO, and R.sub.2 O is selected from the group of alkali metal oxides. The foams comprise hydrogen-containing cells produced through the inclusion in the batch of a hydrogen-generating agent selected from the group of ammonium salts and/or a combination of amines and/or carbohydrates and/or hydrocarbons with phosphates.

Abstract: A method for molding calcium phosphate type glass, which comprises pouring a melt of calcium phosphate into a mold, and cooling and solidifying it, wherein the mold contains boron nitride at least at the surface thereof.

Abstract: Glass ceramic comprising apatite crystals and at least 50% by weight of wollastonite crystals and a process for producing the same are disclosed. The glass ceramic contains from 45 to 56% by weight of CaO, from 1 to less than 10% by weight of P.sub.2 O.sub.5, from 30 to 50% by weight of SiO.sub.2, from 0 to 5% by weight in total of one or two of MgO and Y.sub.2 O.sub.3, and from 0 to 5% by weight of one or more of F.sub.2, Na.sub.2 O, K.sub.2 O, Li.sub.2 O, Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, SrO, Nb.sub.2 O.sub.5 and Ta.sub.2 O.sub.5, with the total content of CaO, P.sub.2 O.sub.5 and SiO.sub.2 being at least 90% by weight. The glass ceramic exhibits excellent biocompatibility and has improved strength.

Abstract: A high-strength glass-ceramic containing apatite crystals or .beta.-tricalcium phosphate crystals, and anorthite crystals, and a process for producing the same are disclosed. The glass-ceramic has an excellent biocompatibility and is useful as an implant material such as an artificial dental root and an artificial bone.

Abstract: Dental materials using calcium phosphate glass-ceramics and having the color tone with high approximation to that of natural teeth. In those dental materials, calcium phosphate composite, nickel oxide and one or more other type of compounds selected from oxides of iron, manganese, cerium, titanium and tungsten, are contained as coloring component. Also, if necessary, Al.sub.2 O.sub.3 and/or SiO.sub.2 is contained as a color assisting agent in that composite. The calcium phosphate glass-ceramic according to this invention consists of the same components as that of natural teeth. Besides, it is possible to adjust the color tone delicately to match with the color tone of each individual`s teeth. Moreover, the coloring components are incorporated in crystals of calcium phosphate. Consequently, they cause no elution during use and are therefore ideal as dental material.

Abstract: Calcium phosphate type crystallizable glass for dental materials, which is composed essentially of from 41 to 49.5 mol % of CaO, from 50 to 58.5 mol % of P.sub.2 O.sub.5 and from 0.5 to 5 mol % of Al.sub.2 O.sub.3, and which has an atomic ratio of calcium to phosphorus (Ca/P) within a range of from 0.35 to 0.49.

Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is one or more of magnesium, zinc, strontium, and calcium, and where k, and x are numerals in the ranges of 1.00 to 1.04, and 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of boron oxide, silicon dioxide, and, possibly, at least one of barium oxide, magnesium oxide, zinc oxide, strontium oxide, and calcium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dielectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided form are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere.

Abstract: A phase transformation-toughened glass ceramic and a process for making it are disclosed. A mixture of particulate network-forming oxide, network-modifying oxide, and zirconium oxide is heated to yield a homogeneous melt, and this melt is then heat-treated to precipitate an appreciable quantity of tetragonal zirconia, which is retained at ambient temperature to form a phase transformation-toughened glass ceramic. Nucleating agents and stabilizing agents may be added to the mixture to facilitate processing and improve the ceramic's properties. Preferably, the mixture is first melted at a temperature from 1200.degree. to 1700.degree. C. and is then heat-treated at a temperature within the range of 800.degree. to 1200.degree. C. in order to precipitate tetragonal ZrO.sub.2.The composition, as well as the length and temperature of the heat-treatment, must be carefully controlled to prevent solution of the precipitated tetragonal zirconia and subsequent conversion to the monoclinic phase.

Abstract: This invention is directed to the production of transparent, translucent, or opaque glass-ceramic articles containing BPO.sub.4 as the predominant crystal phase by heat treating precursor glass articles consisting essentially, expressed in terms of weight percent on the oxide basis, of about:SiO.sub.2 : 10-50B.sub.2 O.sub.3 : 5-35P.sub.2 O.sub.5 : 25-75SiO.sub.2 +P.sub.2 O.sub.5 +B.sub.2 O.sub.3 : >90.

Abstract: Compositions of metal oxides which may be melted and cooled to produce glasses are disclosed. The glasses may be heat treated to produce glass-ceramics. The glasses have good transmittances for electromagnetic radiation in the ultraviolet, infrared and visible spectra, while the glass-ceramics have good transmittances of infrared radiation. Other physical properties make these materials desirable for purposes such as radomes.

Abstract: A high strength glass-ceramic containing apatite and alkaline earth metal silicate (diopside/forsterite/akermanite) crystals having an excellent affinity for a living body and a process for producing the same are disclosed. The glass-ceramic is useful as an implant material such as an artificial dental root and an artificial bone.

Abstract: A process for producing a refractory material comprising essentially beta'-SiAlON wherein initial reactants comprising Al.sub.2 O.sub.3 and SiO.sub.2 are nitrided for sufficient times and temperatures to convert at least a portion of the initial reactants to at least a portion of effective reactants and the effective reactants are then further heated to produce an essentially beta'-SiAlON refractory material.

Abstract: Solid, crystalline glass ceramic compositions which are useful as ionic conductor materials, especially for use as solid electrolytes in high temperature, high energy density storage batteries. The glass ceramics are derived from sodium or calcium borates containing one or more metal halide, preferably the chlorides and bromides of the metals from Group 2 to 8 of the Periodic Table of the Elements.

Abstract: A process for producing a refractory material comprising essentially beta'-SiAlON wherein the initial reactants include discrete particles of an SiO.sub.2 source and discrete particles of an Al.sub.2 O.sub.3 source.

Abstract: A composition and method of making a high strength semi-crystalline ceramic material of the lithium, aluminum, silicon oxides system type. The composition is characterized by a relatively narrow range of lithium, aluminum, silicon and potassium oxides to form a base glass batch and is modified by including a novel proportional combination of the catalysts or modifiers comprising the components TiO.sub.2, ZrO.sub.2 and SnO.sub.2 and including one or more additives taken from a group consisting of B.sub.2 O.sub.3, MgO, Cr.sub.2 O.sub.3, CeO.sub.2, V.sub.2 O.sub.5 and Na.sub.2 O within specific percentage ranges.The composition is formed and subjected to heat treatment within certain time and temperature steps to provide for the desired degree, size and type of crystalline formation (lithium disilicate, cristobalite, spinel) which exhibits the desired physical, mechanical and chemical properties which include a superior resistance to high speed projectiles for armor applications.

Abstract: A phosphate glass such as calcium metaphosphate (Ca(PO.sub.4).sub.2) is heat-treated in a temperature gradient to obtain a crystallized glass (glass-ceramics) made of oriented fiber like crystals which has high bending strength in an abraded state.

Abstract: A D-E hysteresis loop of ferroelectrics known in the art has a square shape when the ferroelectrics are a BaTiO.sub.3 single crystal. Such ferroelectrics are used as a non-linear dielectric element of, for example a pulse generating device. The non-linear dielectric element according to the present invention consists of a polycrystal mainly composed of Ba(Ti.sub.0.90-0.98 Sn.sub.0.02-1.00)O.sub.3 and having an average grain diameter of from 10 to 60 .mu.m. The non-linearity is excellent and the temperature dependence of the non-linearity is considerably low.

Abstract: Glass ceramic materials having controllable temperature coefficients of dielectric constant or capacitance (TCC) are provided. The ceramic component of the composition possesses paraelectric properties at least over the temperature range of -55.degree. C. to 125.degree. C. and can be controllably crystallized from the glassy matrix initially formed. Heat treatment of the glass produces crystallization of the ceramic component and results in glass ceramic materials with controlled TCC values which are useful as capacitors, resonators, microwave substrates, and the like because of their low dielectric loss characteristics and temperature stability.

Abstract: Phosphate glass compositions are described comprising from 8 to 35 wt % P.sub.2 O.sub.5, from 8 to 48 wt % SiO.sub.2 and GeO.sub.2, provided that the GeO content is not more than 6 wt %, from 3 to 18 wt % B.sub.2 O.sub.3, from 16 to 28 wt % Al.sub.2 O.sub.3, and from 8 to 33 wt % CaO, MgO, SrO, and BaO, provided that the sum of the MgO, SrO, and BaO contents is not more than 15 wt %, andwherein the sum of the above-described oxides comprises at least 88 wt % of the total composition and the ratio of the sum of the CaO, MgO, SrO and BaO contents to the P.sub.2 O.sub.5 content ranges from 0.6/1 to 1.

Abstract: Partially devitrified porcelain compositions are provided which are comprised of a mixture, based on its oxide content, of barium oxide (BaO), magnesium oxide (MgO) or a mixture of magnesium oxide with certain other oxides (CaO,ZnO), boron trioxide (B.sub.2 O.sub.3) and slicon dioxide (SiO.sub.2). In accordance with this invention the porcelain compositions are applied to the metal core and fired to provide a partially devitrified porcelain coating on the metal core. The coating has a very low viscosity at its initial fusion point and then almost instantaneous high viscosity due to partial devitrification. The fired coating has a deformation temperature of at least 700.degree. C. and a high coefficient of thermal expansion of at least about 110.times.10.sup.-7 /.degree.C.

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: Monolithic capacitors having Q's of 3500 include copper electrodes buried in a non-reducible body that consists of a crystalline magnesium titanate phase and an intergranular glass phase. The crystalline phase contains magnesium meta-titanate and/or ortho-titanate. Magnesium di-titanate is excluded from the body as are the oxides of lead, bismuth and cadmium, which materials are reducible at the firing conditions necessary to preserve the integrity of the copper electrodes.

Abstract: A low temperature-sinterable dielectric composition is provided, whose sintered composition when prepared by firing a uniform mixture consisting of lead ferrotungstate, lead titanate and manganese dioxide at a temperature of not higher than 1,000.degree. C. has the general formula A.Pb(Fe.sub.2/3 W.sub.1/3).sub.1-x Ti.sub.x O.sub.3 +B.MnO.sub.2, wherein 0.005.ltoreq..times..ltoreq.0.65, A=0.95-0.9995, and B=0.0005-0.05, a relative dielectric constant of at least 2,000 at 25.degree. C., a dissipation factor (tan .delta.) of not more than 5% at 25.degree. C., and a specific resistance of at least 10.sup.9 .OMEGA..cm at 25.degree. C. Also provided is a thick film capacitor having a dielectric layer prepared from said composition.