A polycrystalline diamond construction has a body of polycrystalline diamond (PCD) material; and a cemented carbide substrate bonded to the body of polycrystalline material along an interface. The cemented carbide substrate has tungsten carbide particles bonded together by a binder material, the binder material comprising Co; and the tungsten carbide particles form at least around 70 weight percent and at most around 95 weight percent of the substrate. The cemented carbide substrate has a bulk volume, the bulk volume of the cemented carbide substrate having at least around 0.1 vol. % of inclusions of free carbon having a largest average size in any one or more dimensions of less than around 40 microns.

A polycrystalline diamond construction has a body of polycrystalline diamond (PCD) material; and a cemented carbide substrate bonded to the body of polycrystalline material along an interface. The cemented carbide substrate has tungsten carbide particles bonded together by a binder material, the binder material comprising Co; and the tungsten carbide particles form at least around 70 weight percent and at most around 95 weight percent of the substrate. The cemented carbide substrate has a bulk volume, the bulk volume of the cemented carbide substrate having at least around 0.1 vol. % of inclusions of free carbon having a largest average size in any one or more dimensions of less than around 40 microns.

A method of processing a polycrystalline diamond (PCD) material having a non- diamond phase with a catalyst/solvent material includes leaching an amount of the catalyst/solvent from the PCD material by exposing at least a portion of the PCD material to a leaching mixture, the leaching mixture comprising hydrofluoric acid at a molar concentration of between 12 M to around 28 M, nitric acid at a molar concentration of between around 3 M to around 10 M, and water.

A method of processing a polycrystalline diamond (PCD) material having a non- diamond phase with a catalyst/solvent material includes leaching an amount of the catalyst/solvent from the PCD material by exposing at least a portion of the PCD material to a leaching mixture, the leaching mixture comprising hydrofluoric acid at a molar concentration of between 12 M to around 28 M, nitric acid at a molar concentration of between around 3 M to around 10 M, and water.

A composite polycrystal contains polycrystalline diamond formed of diamond grains that are directly bonded mutually, and compressed graphite dispersed in the polycrystalline diamond.

A double-tube connection structure for detonation synthesis, a detonation synthesis device and an application thereof are provided. The double-tube connection structure for detonation synthesis includes a drive tube, a sample tube, fixing components, and end plugs provided at ports of the sample tube. The drive tube is sleeved outside the sample tube, cavities are provided between the drive tube and the sample tube, and between the drive tube and the end plug. The fixing components are provided on two ends of the drive tube and the sample tube. After detonation, a detonation wave is transferred from top to bottom. Under the action of the detonation wave, the drive tube performs convergent sliding motion towards the sample tube, and covers outsides of the sample tube, and the top end plug and the bottom end plug of the sample tube. A detonation synthesis device includes the double-tube connection structure for detonation synthesis.

The present disclosure describes a compression device, a compression process, a method of producing synthetic materials and a method of sample characterization. The present disclosure belongs to the fields of Physics, Chemistry and Engineering.

A synthetic single crystal diamond containing 100 ppm or more and 1500 ppm or less of nitrogen atoms, in which the synthetic single crystal diamond contains aggregates each composed of one vacancy and two to four nitrogen atoms present adjacent to the vacancy, a ratio b/a of a length b of a short diagonal line to a length a of a long diagonal line of diagonal lines of a Knoop indentation in a <110> direction in a {001} plane of the synthetic single crystal diamond is 0.08 or less, and the Knoop indentation is formed by measuring Knoop hardness in the <100> direction in the {001} plane of the synthetic single crystal diamond according to JIS Z 2251: 2009 under conditions of a temperature of 23° C.±5° C. and a test load of 4.9 N.

A synthetic single crystal diamond containing 100 ppm or more and 1500 ppm or less of nitrogen atoms, in which the synthetic single crystal diamond contains aggregates each composed of one vacancy and two to four nitrogen atoms present adjacent to the vacancy, a ratio b/a of a length b of a short diagonal line to a length a of a long diagonal line of diagonal lines of a Knoop indentation in a <110> direction in a {001} plane of the synthetic single crystal diamond is 0.08 or less, and the Knoop indentation is formed by measuring Knoop hardness in the <100> direction in the {001} plane of the synthetic single crystal diamond according to JIS Z 2251: 2009 under conditions of a temperature of 23° C.±5° C. and a test load of 4.9 N.

[Technical Problem]To provide diamond grits with enhanced friability, and method for the production comprising in combination internal microcracks within the diamond particle and surface irregularities, with or without a layer of non-diamond carbon covering the particle surface.

[Solution to Problem]

The diamond grits of the invention consist of diamond particles synthesized by a static ultrahigh pressure-high temperature process, comprising both microcracks generated within the particles due to the effect of heating, and surface irregularities formed on the particles by oxidizing etching at elevated temperatures.

The production method comprises providing a starting volume of diamond particles, from a synthesizing process in a static ultrahigh pressure-high temperature process, subjecting said diamond particles to a heating process in intimate contact with an oxidizing etchant at a temperature of 800° C. or higher, generating thus microcracks within the diamond particles and also causing to corrode the particle surface thus forming increased surface irregularities, and recovering the treated diamond particles.