Abstract: A superabrasive compact and a method of making the superabrasive compact are disclosed. A method of making a superabrasive compact includes the steps of providing a plurality of superabrasive particles; subjecting the plurality of superabrasive particles to conditions of a first elevated temperature and pressure; and crushing the plurality of superabrasive particles into a pill under the first elevated high pressure and high temperature.

Abstract: A superabrasive compact and a method of making the superabrasive compact are disclosed. A method of making a superabrasive compact includes the steps of providing a plurality of superabrasive particles; subjecting the plurality of superabrasive particles to conditions of a first elevated temperature and pressure; and crushing the plurality of superabrasive particles into a pill under the first elevated high pressure and high temperature.

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 preblocking and preshaping a discolored natural diamond to prevent its breakage in a high pressure/high temperature (HP/HT) press, placing said discolored natural diamond in a pressure transmitting medium which is consolidated into a pill. Next, the pill is placed into a HP/HT press at elevated pressure and elevated temperature within the graphite-stable or 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 and fancy colored diamonds can be made by this method.

Abstract: Polycrystalline gallium nitride (GaN) characterized by having the atomic fraction of gallium ranging from between about 49% to 55%, an apparent density of between about 5.5 and 6.1 g/cm3, and a Vickers hardness of above about 1 GPa. Polycrystalline GaN can be made by hot isostatic pressing (HIPing) at a temperature ranging from about 1150° C. to 1300° C. and a pressure ranging from between about 1 and 10 Kbar. Alternatively, polycrystalline GaN can be made by high pressure/high temperature (HP/HT) sintering at a temperature ranging from about 1200° to 1800° C. and a pressure ranging from about 5 to 80 Kbar.

Abstract: A perovskite feedstock (powder or preform) is placed in a high-pressure cell of a high pressure/high temperature (HP/HT) apparatus and subjected to pressures in excess of about 2 kbar and temperatures above about 800° C. for a time adequate to increase the density of the preform.

Abstract: Polycrystalline gallium nitride (GaN) characterized by having the atomic fraction of gallium ranging from between about 49% to 55%, an apparent density of between about 5.5 and 6.1 g/cm3, and a Vickers hardness of above about 1 GPa. Polycrystalline GaN can be made by hot isostatic pressing (HIPing) at a temperature ranging from about 1150° C. to 1300° C. and a pressure ranging from between about 1 and 10 Kbar. Alternatively, polycrystalline GaN can be made by high pressure/high temperature (HP/HT) sintering at a temperature ranging from about 1200° to 1800° C. and a pressure ranging from about 5 to 80 Kbar.

Abstract: A perovskite feedstock (powder or preform) is placed in a high-pressure cell of a high pressure/high temperature (HP/HT) apparatus and subjected to pressures in excess of about 2 Kbar and temperatures above about 800° C. for a time adequate to increase the density of the preform.

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: An improved process for converting hexagonal boron nitride (HBN) particles into cubic boron nitride (CBN) in a high pressure/high temperature apparatus (HP/HT) is disclosed. More specifically, by using melamine as a catalyst, operating pressures and temperatures as well as catalyst costs, may all be reduced.

Abstract: There is provided a method for making diamond and CBN compacts which comprises positioning a catalyst metal disc and a barrier disc intermediate a diamond or CBN mass and a carbide mass. The catalyst metal disc is adjacent to the diamond or CBN layer and the barrier disc is intermediate said catalyst disc and the carbide mass. In order to prevent unregulated flow of metal bond from said carbide mass to the diamond layer and to prevent depletion of metal bond from the carbide near the carbide/diamond interface, the barrier disc has a surface area virtually identical to that of the carbide mass. Such arrangement of materials is subjected to temperature and pressure conditions within the diamond stable region but below the melting point of the barrier disc.

Abstract: A combination of fused alumina grits with sintered gel alumina abrasive grits is shown to be more effective than either abrasive alone in cutting steel bars with bonded abrasive wheels at intermediate cutting speeds.

Abstract: This invention relates to organically bonded abrasive articles that include grinding aids. It has been determined that when known grinding aids such as alkali metal sulphates and alkali metal chlorides are cofused in about eutectic proportions and added to thermoset resin bonded abrasive articles in the form of finely crushed particles having an approximate eutectic composition that an improved abrasive article results.