Abstract:
An improved high pressure apparatus can include a plurality of complementary die segments. The die segments can have inner surfaces which are shaped to form a die chamber upon assembly of the die segments. A pair of anvils can be oriented such that an anvil is at each end of the die chamber. To prevent the die segments from being forced apart during movement of the anvils, force members can be connected to the die segments. The force members can apply discrete forces to the die segments sufficient to retain the die segments in substantially fixed positions relative to each other during application of force by the pair of anvils. Using such a high pressure apparatus can achieve pressures as high as 10 GPa with improved useful die life and larger reaction volumes.
Abstract:
Thermally-stable polycrystalline diamond materials of this invention comprise a first phase including a plurality of bonded together diamond crystals, and a second phase including a reaction product formed between a binder/catalyst material and a material reactive with the binder/catalyst material. The reaction product is disposed within interstitial regions of the polycrystalline diamond material that exists between the bonded diamond crystals. The first and second phases are formed during a single high pressure/high temperature process condition. The reaction product has a coefficient of thermal expansion that is relatively closer to that of the bonded together diamond crystals than that of the binder/catalyst material, thereby providing an improved degree of thermal stability to the polycrystalline diamond material.
Abstract:
PCD materials of this invention comprise diamond crystals that are bonded together with a catalyst/binder material. The PCD material is prepared by combining diamond grains with a catalyst/binder material either as a premixture or by infiltration during sintering. The PCD material comprises 15 percent by volume or less diamond grains sized 20 micrometers or less. The diamond grains are pressurized under elevated temperature conditions to form the desired PCD material. PCD materials of this invention can constitute the exclusive material phase of a PCD construction, or can form one or more material phase in a multi-phase material microstructure, wherein the multiple material phase can be arranged in an ordered/oriented or random fashion. PCD materials of this invention display improved properties of impact and fatigue resistance, and functional toughness, when used in complex wear environments, when compared to conventional PCs materials comprising intentionally added fine-sized diamond grains.
Abstract:
A method for removing defects at high pressure and high temperature (HP/HT) or for relieving strain in a non-diamond crystal commences by providing a crystal, which contains defects, and a pressure medium. The crystal and the pressure medium are disposed in a high pressure cell and placed in a high pressure apparatus, for processing under reaction conditions of sufficiently high pressure and high temperature for a time adequate for one or more of removing defects or relieving strain in the single crystal.
Abstract:
A belt/die, pre-tensioned loaded windings, or other high-pressure apparatus has a series of annular rings for confining material being subjected to high-pressure treatment. The series of annular rings has an inner annular ring having an inner upper edge, an outer upper edge, an inner lower edge, and an outer lower edge. The inner lower edge is chamfered at an angle of greater than about 60° from the vertical in order to create a transition slope that mitigates tensile stresses.
Abstract:
Supported polycrystalline compacts having improved shear strength, impact, and fracture toughness properties, and methods for making the same under high temperature/high pressure (HT/HP) processing conditions. The method involves a HT/HP apparatus formed of a generally cylindrical reaction cell assembly having an inner chamber of predefined axial and radial extents and containing pressure transmitting medium, and a charge assembly having axial and radial surfaces and formed of at least one sub-assembly comprising a mass of crystalline particles adjacent a metal carbide support layer. The charge assembly is disposed within the chamber of the reaction cell assembly, with the pressure transmitting medium being interposed between the axial and radial surfaces of the charge assembly and the extents of the reaction cell chamber to define an axial pressure transmitting medium thickness, L.sub.h, and a radial pressure transmitting medium thickness, L.sub.r, the ratio of which, L.sub.h /L.sub.r being selected as less than 1. The reaction cell assembly containing the charge assembly then is subjected to HT/HP conditions selected as effective to sinter the crystalline particles into a polycrystalline compact layer and to bond the polycrystalline compact layer at an interface to the metal carbide support layer for forming a metal carbide supported polycrystalline compact. The supported compact is characterized as having an essentially constant or increasing residual compressive stress on the surface of its compact layer as portions of a predefined thickness, W, of its support layer, as measured from the interfaced, are incrementally removed.
Abstract:
In accordance with a method of producing metal sinter bodies, the bodies are provided with degassing openings which are made preferably before sintering of an initial press body part.
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 growing a single crystal of cubic boron nitride semiconductor in a growing container sealed under high pressure and high temperature conditions, which comprises dissolving in a dopant-containing boron nitride solvent a boron nitride starting material placed at a high temperature zone in the growing container, and providing a temperature gradient to the solvent so that the temperature dependence of the solubility is utilized to let the single crystal form and grow at a low temperature zone in the growing container.
Abstract:
A material consisting of grains varying in size from 0.1 to a few microns intergrown so as to form regular aggregates. The geometric shape of the material is preset by a pattern made from a carbon-bearing non-diamond material and corresponds to the shape of the required finished article. The material can be made in any desired number of identical shapes.