Abstract: According to the present disclosure, techniques related to processing of materials for growth of crystals are provided. More particularly, the present disclosure provides apparatus and methods for heating of seed crystals suitable for use in conjunction with a high-pressure vessel for crystal growth of a material having a retrograde solubility in a supercritical fluid, including crystal growth of a group III metal nitride crystal by an ammonobasic or ammonoacidic technique, but there can be others. In other embodiments, the present disclosure provides methods suitable for synthesis of crystalline nitride materials, but it would be recognized that other crystals and materials can also be processed. Such crystals and materials include, but are not limited to, GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, and others for manufacture of bulk or patterned substrates.

Abstract: Embodiments of the disclosure an apparatus for solvothermal crystal growth, comprising: a pressure vessel having a cylindrical shape and a vertical orientation; a cylindrical heater having an upper zone and a lower zone that can be independently controlled; at least one end heater; and an inward-facing surface of a baffle placed within 100 millimeters of a bottom end or top end surface of the growth chamber. The end heater is configured to enable: a variation in the temperature distribution along a first surface to be less than about 10° C., and a variation in the temperature distribution along a second surface to be less than about 20° C., during a crystal growth process.

Abstract: A pressure release mechanism for use with a capsule for processing materials or growing crystals in supercritical fluids is disclosed. The capsule with the pressure release mechanism is scalable up to very large volumes and is cost effective according to a preferred embodiment. In conjunction with suitable high pressure apparatus, the capsule with pressure release mechanism is capable of processing materials at pressures and temperatures of 20-2000 MPa and 25-1500° C., respectively. Of course, there can be other variations, modifications, and alternatives.

Abstract: An apparatus for processing material at elevated pressure, the apparatus comprising: (a) two or more radial restraint structures defining an interior region configured to receive a processing chamber, the radial restraint structures being configured to resist an outward radial force from the interior region; (b) upper and lower crown members being disposed axially on either end of the interior region and configured to resist an outward axial force from the interior region; (c) a first axial restraint structure coupling the upper crown member and the lower crown member to provide axial restraint of the upper crown member and the lower crown; and (d) a second axial restraint structure compressing the two or more radial restraint structures to provide an axial restraint of the two or more radial restraint structures.

Abstract: An apparatus for processing material at elevated pressure, the apparatus comprising: (a) two or more radial restraint structures defining an interior region configured to receive a processing chamber, the radial restraint structures being configured to resist an outward radial force from the interior region; (b) upper and lower crown members being disposed axially on either end of the interior region and configured to resist an outward axial force from the interior region; (c) a first axial restraint structure coupling the upper crown member and the lower crown member to provide axial restraint of the upper crown member and the lower crown; and (d) a second axial restraint structure compressing the two or more radial restraint structures to provide an axial restraint of the two or more radial restraint structures.

Abstract: A pressure release mechanism for use with a capsule for processing materials or growing crystals in supercritical fluids is disclosed. The capsule with the pressure release mechanism is scalable up to very large volumes and is cost effective according to a preferred embodiment. In conjunction with suitable high pressure apparatus, the capsule with pressure release mechanism is capable of processing materials at pressures and temperatures of 20-2000 MPa and 25-1500° C., respectively. Of course, there can be other variations, modifications, and alternatives.

Abstract: A sintered cubic boron nitride (cBN) compact for use in a tool is obtained by sintering a mixture of (i) cubic boron nitride, (ii) aluminum oxide, (iii) one or more refractory metal compounds, and (iv) aluminum and/or one or more non-oxide aluminum compounds. The sintered bodies may have sufficient strength and toughness to be used as a tool material in solid, i.e. not carbide supported, form, and may be useful in heavy machining of cast irons.

Abstract: A sintered cubic boron nitride (cBN) compact for use in a tool is obtained by sintering a mixture of (i) cubic boron nitride, (ii) aluminum oxide, (iii) one or more refractory metal compounds, and (iv) aluminum and/or one or more non-oxide aluminum compounds. The sintered bodies may have sufficient strength and toughness to be used as a tool material in solid, i.e. not carbide supported, form, and may be useful in heavy machining of cast irons.