HPHT press system includes a thermal insulation layer. The thermal insulation layer includes CsCl, CsBr, CsI, or a combination thereof, and the thermal insulation layer is electrically insulating. The thermal insulation layer may include a thermal insulation sleeve and/or a thermal insulation button for an HPHT cell.

A high-pressure pump comprising an elongated casing and a hollow interior formed along a central axis thereof. At least one partition may be axially fixed within the elongated casing such that it divides the hollow interior. First and second pressure differential devices may be disposed on opposite sides of the at least one partition and each have a rotary shaft extending there through. A first rotary shaft extending through the first pressure differential device may be axially fixed by the at least one partition and rotationally fixed to a second rotary shaft extending through the second pressure differential device. The high-pressure pump may be driven by a servomotor and used in a high-pressure press.

Methods of forming polycrystalline diamond compacts include employing field assisted sintering techniques with high temperature and high pressure sintering techniques. For example, a particle mixture that includes diamond particles may be sintered by subjecting the particle mixture to a high temperature and high pressure sintering cycle, and pulsing direct electrical current through the particle mixture during at least a portion of the high temperature and high pressure sintering cycle. The polycrystalline diamond compacts may be used to form cutting elements for earth-boring tools. Sintering systems are configured to perform such sintering processes.

Methods of forming polycrystalline diamond compacts include employing field assisted sintering techniques with high temperature and high pressure sintering techniques. For example, a particle mixture that includes diamond particles may be sintered by subjecting the particle mixture to a high temperature and high pressure sintering cycle, and pulsing direct electrical current through the particle mixture during at least a portion of the high temperature and high pressure sintering cycle. The polycrystalline diamond compacts may be used to form cutting elements for earth-boring tools. Sintering systems are configured to perform such sintering processes.

A container assembly for use in a high-pressure press having a central pressure cell and a method of sealing a central pressure cell. The container assembly includes a container that receives a sample to be pressed, and a gasket distinct from the container, the gasket meeting the container at an interface. The container and the gasket are dimensioned to locate the interface within the central pressure cell.

In an embodiment, a cell assembly for use in a high-pressure cubic press may include at least one can assembly containing a diamond volume. The at least one can assembly may include an end surface in proximity to the diamond volume. The cell assembly may include at least one heating element including a major surface generally opposing and positioned adjacent to the end surface of the at least one can assembly. The at least one heating element may be positioned and configured to heat the diamond volume. The cell assembly may include at least one pressure transmitting medium extending about the at least one can assembly, and a gasket medium that defines a receiving space configured to receive the at least one can assembly, the one or more heating elements, and the at least one pressure transmitting medium.

A high-pressure high-temperature cell including two or more thermal insulation layers is described. A high-pressure high-temperature cell including a current path through a thermal insulation layer, the current path being electrically connected to a heating element and having an indirect path through the thermal insulation layer, is also described. High-pressure high-temperature press systems including the foregoing high-pressure high-temperature cells alone or in combination are also disclosed.

Luminescent diamond is made subjecting a volume of diamond grains and catalyst material to high-pressure/high-temperature (HPHT) conditions. A pressure apparatus and/or a pressure cell is specially configured to impose a differential or asymmetric pressure onto the diamond volume during the HPHT conditions. This subjects the diamond grains to differential strain that increases the degree of plastic deformation of the diamond grains to increase the formation of nitrogen vacancy centers. Diamond pellets formed by such process and subjected to differential pressure can have an aspect ratio, or an aspect ratio change, of greater than one. The temperature of the HPHT process is 1.800 C. or less to facilitate desired nitrogen migration to preferentially promote formation of NV centers over NVN and N3 centers in the diamond pellets to provide a degree of luminescence in a red wavelength spectrum greater than diamond pellets formed by some other HPHT processes.

High-pressure high-temperature presses are commonly employed to create superhard materials used in such fields as road milling, mining and trenching, to breakup tough materials such as asphalt, concrete and rock. Many such presses comprise a plurality of piston assemblies that may act in concert to pressurize a cell. Such a cell may comprise a body with at least three canisters disposed therein, each comprising an axis passing through a center of the body. Such a configuration may allow for maximum planes of symmetry within the cell.

High-pressure high-temperature presses are commonly employed to create superhard materials used in such fields as road milling, mining and trenching, to breakup tough materials such as asphalt, concrete and rock. Many such presses comprise a plurality of piston assemblies that may act in concert to pressurize a cell. Such a cell may comprise a body with a plurality of canisters disposed therein and at least one unique heater element adjacent each of the canisters. Heat may be generated within such a press by forming an electrical circuit with the unique heater element and anvils surrounding the cell.