Abstract: A jadeite material has a thickness in excess of about 1.0 mm and CIELAB indices of L*>42, a*<?6, and b*>+6. The grain size of the jadeite material is less than about 30 microns and is an equiaxed grain structure. The jadeite material has an optical transmission peak between 500 and 565 nm with an I/IO optical transmission ratio of over 40%. The first step in making the jadeite material is to wrap a glass block, convertible by HP/HT into jadeite and having a nominal composition of NaAlSi2O6, with a graphite or refractive metal sheet. The wrapped glass block is placed in an HP/HT apparatus, rapidly heated, and subjected therein to a pressure in excess of about 3 GPa and a temperature in excess of about 1000° C. for a time adequate to convert the glass block into jadeite. The jadeite material then is cooled and the pressure subsequently released.

Abstract: A sintered cubic boron nitride (cBN) compact for use in a tool is composed of between about 60 and 80 vol-% cBN having a volumetric mean particle size of between about 3 to 6 &mgr;m and between about 40 and 20 vol-% of a ceramic binder phase. The ceramic binder is composed of between about 20 and 60 vol-% of one or more of a carbide, nitride, or boride of a Group IVB or VIB metal, and between about 40 and 80 vol-% of one or more of carbides, nitrides, borides, or oxides of aluminum. The cBN compact additionally contains between about 3 and 15 wt-% tungsten. The cBN compacts are especially useful in machining iron and like chemically reactive parts, especially where such parts are powder metal parts.

Abstract: A sintered cubic boron nitride (cBN) compact for use in a tool is composed of between about 60 and 80 vol-% cBN having a volumetric mean particle size of between about 3 to 6 &mgr;m and between about 40 and 20 vol-% of a ceramic binder phase. The ceramic binder is composed of between about 20 and 60 vol-% of one or more of a carbide, nitride, or boride of a Group IVB or VIB metal, and between about 40 and 80 vol-% of one or more of carbides, nitrides, borides, or oxides of aluminum. The cBN compact additionally contains between about 3 and 15 wt-% tungsten. The cBN compacts are especially useful in machining iron and like chemically reactive parts, especially where such parts are powder metal parts.

Abstract: A pressure vessel for processing at least one material in a supercritical fluid. The pressure vessel includes a self-pressurizing capsule for containing at least one material and the supercritical fluid in a substantially air-free environment, a pressure transmission medium surrounding the capsule for maintaining an outer pressure on the capsule, at least one heating element insertable in the pressure transmission medium such that the heating element surrounds the capsule, a temperature measurement means for measuring a temperature of the capsule, a temperature controller for controlling the temperature and providing power to the heating element, a restraint to contain and hold in place the capsule, the pressure transmission medium, and the heating element, and at least one seal between the restraint and the pressure transmission medium for preventing escape of the pressure transmission medium.

Abstract: A jadeite material has a thickness in excess of about 1.0 mm and CIELAB indices of L*>42, a*<−6, and b*>+6. The grain size of the jadeite material is less than about 30 microns and is an equiaxed grain structure. The jadeite material has an optical transmission peak between 500 and 565 nm with an I/IO optical transmission ratio of over 40%. The first step in making the jadeite material is to wrap a glass block, convertible by HP/HT into jadeite and having a nominal composition of NaAlSi2O6, with a graphite or refractive metal sheet. The wrapped glass block is placed in an HP/HT apparatus, rapidly heated, and subjected therein to a pressure in excess of about 3 GPa and a temperature in excess of about 1000° C. for a time adequate to convert the glass block into jadeite. The jadeite material then is cooled and the pressure subsequently released.

Abstract: A method of forming polycrystalline rare earth oxide ceramic scintillators formed by dissolving a mixture of oxides of the scintillator in an aqueous hydrochloric or nitric acid solution to form a rare earth solution, precipitating oxalates from the rare earth solution, calcining the oxalates to form the respective oxides, cold pressing the oxides to form a compact, and sintering the compact in a reducing atmosphere or vacuum to form the scintillator, the method being improved by precipitating the oxalates by admixing the rare earth solution with an oxalic solution comprised of, oxalic acid and ammonium ions in an amount that disperses the oxalate precipitates.