Abstract:
A high pressure reaction vessel includes an inner bushing surrounding a reaction charge. The inner bushing is formed of at least one material having a low shear strength that undergoes a polymorphic phase change to a more dense phase within the operating pressure range of the reaction vessel. The bushing may be formed of at least two low shear strength materials with one of the materials undergoing polymorphic phase change to a more dense phase. The one of the two materials which undergoes a polymorphic phase change forms between 10% and 90% of the total volume of the inner bushing. In another embodiment, a pressure transmitting media and an electrical resistance heater tube are concentrically arranged within the inner bushing. The pressure transmitting media is formed of a low shear strength material that undergoes a polymorphic phase change to a more dense phase. In both embodiments, the low shear strength material undergoing polymorphic phase change is potassium bromide.
Abstract:
A method for producing crystals of materials is described. The method comprises providing a pressure-resistant body having a nucleus of a starting material being crystallized in the inside thereof. The nucleus is applied with an energy which is capable of passing through the pressure-resistant body and being absorbed by the starting material, by which the nucleus is heated and melts. The melt is then gradually cooled under pressure to form crystals of the material. A laser beam or high frequency induction heating technique is used for heating the nucleus.
Abstract:
A high-hardness and high-strength carbon material is produced by disposing a body of graphite carbon, e.g. precompacted graphite or a mass of powdery graphite carbon, of a predetermined shape and dimension in a collapsible receptacle shaped and dimensioned to tightly retain the body therein, the receptacle being collapsible at least one-dimensionally under external pressure while holding the body against expansion. High pressure is applied to the body while the body is heated to an elevated temperature and for a sufficient period such as to cause a central region of the body to be liquefied and the remainder thereof to be sintered. While under continuous pressure, the body is cooled to give in carbon material.
Abstract:
The present invention relates to a reaction vessel adapted to withstand pressures and temperatures of the magnitude associated with the manufacture of diamond products and boron nitride (BN) and similar hard materials. The reaction vessel has an outer chamber or shell formed from steel and an inner reaction chamber. Known vessels of this type must be provided with a thick layer of insulating material between the reaction chamber and the outer steel shell to protect the outer shell from the heat of the diamond-forming process carried on in the reaction chamber. The quantity of insulating material required within the vessel for adequate protection of the outer shell is relatively large as compared to the area of the outer shell. Accordingly, the amount of available space remaining within the vessel for the diamond-forming reaction is limited, thus limiting the size of the diamonds formed. The present invention provides a reaction vessel with a cooling system which eliminates the need for the large quantity of insulating material in the known vessels. As such, the reaction vessel provides a significantly larger reaction chamber for the diamond-forming process, and the resultant diamonds are up to a thousand times larger than those formed from known reaction vessels. In one embodiment of the invention, the cooling system includes a plurality of truncated steel pyramids arranged to form flow passages or channels for a cooling fluid adjacent to the inner wall of the vessel's outer steel shell to absorb and disperse heat before it penetrates the outer steel shell.
Abstract:
A high pressure, high temperature, piston-cylinder type apparatus utilizing a soft, ductile, electrically conductive material as a driver element to transmit pressure from the piston to a charge in the cylinder. The driver element, preferably made of lead, or the like, is placed in the pressure cylinder between an advanceable piston and a stationary sleeve of insulating material surrounding an electrically heatable core of charge material. As the piston is advanced, the lead driver element deforms into the end of the sleeve of insulating material and maintains pressure on the core without deformation of the sleeve of insulating material.
Abstract:
A high pressure, high temperature, piston-cylinder type apparatus which utilizes a soft, ductile, electrically conductive material as a driver element to transmit pressure from the piston to a charge in the cylinder. The driver element, preferably made of zinc or lead, or the like is placed in the pressure cylinder between an advanceable piston and a stationary sleeve of insulating material surrounding an electrically heatable core of charge material. As the piston is advanced, the driver element deforms into the end of the sleeve of insulating material and maintains pressure on the core with minimal deformation of the sleeve of insulating material.
Abstract:
A cell adapted for producing high temperatures and high pressures comprising a three-layered box.The inner layer is made of an electrically insulating material, the intermediate layer is made of a conductive material and the outer layer is made of an electrically and thermally insulating material. An electric current is permitted to flow through the conductive intermediate layer via electric contacts disposed in the outer layer to heat samples in the sealed chamber.Gaskets, mounted outside the cell for sealing high pressure in the cell, are prevented from being heated whereby a high pressure sealing effect is maintained effectively even though the cell is heated at a high temperature.