Abstract: The present invention is directed to a method for changing the color of colored natural diamonds. The method includes placing a discolored natural diamond in a pressure-transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature for a time sufficient to improve the color of the diamond. The diamond may be exposed at elevated-pressure and elevated-temperature conditions within the graphite-stable region of the carbon-phase diagram—without significant graphitization of the diamond, or above the diamond-graphite equilibrium and within the diamond-stable region of the carbon-phase diagram. Finally, the diamond is recovered from said press. Colorless Type Ia and Type II diamonds may be made by this method.

Abstract: A method of forming at least one single crystal of a Group III metal nitride. The method includes the steps of: providing a flux material and a source material comprising at least one Group III metal selected from the group consisting of aluminum, indium, and gallium, to a reaction vessel; sealing the reaction vessel; heating the reaction vessel to a predetermined temperature and applying a predetermined pressure to the vessel. The pressure is sufficient to suppress decomposition of the Group III metal nitride at the temperature. Group III metal nitrides, as well as electronic devices having a Group III metal nitride substrate formed by the method are also disclosed.

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 curable resin composition comprises a poly(arylene ether), an acryloyl monomer, an allylic monomer, and an abrasive filler. The composition tolerates high filler contents, cures rapidly, and exhibits excellent toughness after curing. Useful articles prepared from the composition include grinding wheels and cut-off wheels having good wear characteristics.

Abstract: The present invention is directed to a method for changing the color of colored natural diamonds. The method includes placing a discolored natural diamond in a pressure-transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature for a time sufficient to improve the color of the diamond. The diamond may be exposed at elevated-pressure and elevated-temperature conditions within the graphite-stable region of the carbon-phase diagram—without significant graphitization of the diamond, or above the diamond-graphite equilibrium and within the diamond-stable region of the carbon-phase diagram. Finally, the diamond is recovered from said press. Colorless Type Ia and Type II diamonds may be made by this method.

Abstract: Molded articles in the form of grinding/cut-off wheels, drill bits, reamers, knife, blade, etc., having a core section or sections comprising a moldable resin of some intensive property, e.g., hardness, concentration, etc., and a surface layer or rim or section(s) comprising another moldable resin of different magnitude of the same intensive property e.g., hardness, concentration, etc., and abrasive articles selected from one or more of diamond, cubic boron nitride (CBN), alumina, SiC, garnet, and mixtures thereof. The articles are characterized in that a) the resins comprising the sections are miscible and diffusively or convectively mixed; b) a composition ratio of the abrasive articles in the resins is decreased inwardly from a surface of said molded article on a scale of the mesh size of the abrasive and article size; and c) the resins comprising the sections are miscible and diffusively mixed.

Abstract: The present invention is directed to a method for changing the color of colored natural diamonds. The method includes placing a discolored natural diamond in a pressure-transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature for a time sufficient to improve the color of the diamond. The diamond may be exposed at elevated-pressure and elevated-temperature conditions within the graphite-stable region of the carbon-phase diagram—without significant graphitization of the diamond, or above the diamond-graphite equilibrium and within the diamond-stable region of the carbon-phase diagram. Finally, the diamond is recovered from said press. Colorless Type Ia and Type II diamonds may be made by this method.

Abstract: An abrasive diamond composite formed from coated diamond particles and a matrix material. The diamonds have a protective coating formed from a refractory material having a composition MCxNy, that prevents corrosive chemical attack of the diamonds by the matrix material. The abrasive diamond composite may further include an infiltrant, such as a braze material. Alternatively, the abrasive diamond composite may include a plurality of coated diamond particles and a braze material filling interstitial spaces between the coated diamond particles. Methods of making such abrasive diamond composites are also disclosed.

Abstract: A method of forming at least one single crystal of a Group III metal nitride. The method includes the steps of: providing a flux material and a source material comprising at least one Group III metal selected from the group consisting of aluminum, indium, and gallium, to a reaction vessel; sealing the reaction vessel; heating the reaction vessel to a predetermined temperature and applying a predetermined pressure to the vessel. The pressure is sufficient to suppress decomposition of the Group III metal nitride at the temperature. Group III metal nitrides, as well as electronic devices having a Group III metal nitride substrate formed by the method are also disclosed.

Abstract: A curable resin composition comprises a poly(arylene ether), an acryloyl monomer, an allylic monomer, and an abrasive filler. The composition tolerates high filler contents, cures rapidly, and exhibits excellent toughness after curing. Useful articles prepared from the composition include grinding wheels and cut-off wheels having good wear characteristics.

Abstract: The present invention is directed to a method for changing the color of colored natural diamonds. The method includes placing a discolored natural diamond in a pressure-transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature for a time sufficient to improve the color of the diamond. The diamond may be exposed at elevated-pressure and elevated-temperature conditions within the graphite-stable region of the carbon-phase diagram—without significant graphitization of the diamond, or above the diamond-graphite equilibrium and within the diamond-stable region of the carbon-phase diagram. Finally, the diamond is recovered from said press. Colorless Type Ia and Type II diamonds may be made by this method.

Abstract: A curable resin composition comprises a poly(arylene ether), an acryloyl monomer, an allylic monomer, and an abrasive filler. The composition tolerates high filler contents, cures rapidly, and exhibits excellent toughness after curing. Useful articles prepared from the composition include grinding wheels and cut-off wheels having good wear characteristics.

Abstract: A horizontal frame saw is equipped with a plurality of generally parallel, spaced-apart blades for cutting granite. Each of the blades has a cutting edge with diamond cutting segments mounted thereon for engaging the granite with a swinging motion for cutting of the granite.

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 curable resin composition comprises a poly(arylene ether), an acryloyl monomer, an allylic monomer, and an abrasive filler. The composition tolerates high filler contents, cures rapidly, and exhibits excellent toughness after curing. Useful articles prepared from the composition include grinding wheels and cut-off wheels having good wear characteristics.

Abstract: An abrasive diamond composite formed from coated diamond particles and a matrix material. The diamonds have a protective coating formed from a refractory materia1 having a composition MCxNy, that prevents corrosive chemical attack of the diamonds by the matrix material. The abrasive diamond composite may further include an infiltrant, such as a braze material. Alternatively, the abrasive diamond composite may include a plurality of coated diamond particles and a braze material filling interstitial spaces between the coated diamond particles. Methods of making such abrasive diamond composites are also disclosed.

Abstract: The present invention is directed to a method for treating discolored natural diamond, especially Type IIa diamond and Type IaA/B diamond with nitrogen as predominantly B centers, for improving its color. The method includes placing a discolored natural diamond in pressure transmitting medium powder which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature within the diamond stable range of the carbon phase diagram for a time sufficient to improve the color of said diamond. Finally, the diamond is recovered from said press. Colorless diamond can be made by this method.

Abstract: The present invention is directed to a method for treating discolored natural diamond, especially Type IIa diamond and Type IaA/B diamond with nitrogen as predominantly B centers, for improving its color. The method includes placing a discolored natural diamond in a pressure transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature within the graphite stable range of the carbon phase diagram for a time sufficient to improve the color of said diamond. Finally, the diamond is recovered from said press. Colorless diamond can be made by this method.