A diamond substrate according to an embodiment includes a diamond layer including at least one first element selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi), the number of threefold coordinated atoms of the at least one first element in the diamond layer being larger than the number of fourfold coordinated atoms of the at least one first element in the diamond layer, a surface of the diamond layer having an off angle of 10 degrees or less with respect to a (111) face.

A foamed skeleton reinforced composite, comprising a foamed skeleton and a matrix material. The foamed skeleton is selected from at least one of a metal foamed skeleton, an inorganic non-metal foamed skeleton, and an organic foamed skeleton. The matrix material is selected from a metal or a polymer.

Provided is a single crystal diamond having a lowered dislocation density. The single crystal diamond (10) is provided with single crystal diamond layers (2, 3). One single crystal diamond layer (2) is formed on a diamond substrate (1) and contains point defects. The other single crystal diamond layer (3) is grown on the single crystal diamond layer (2). The single crystal diamond layers (2, 3) have a lower dislocation density than the diamond substrate.

Provided is a hot filament CVD device capable of easily attaching, detaching, and replacing a filament. The hot filament CVD device includes a chamber, a base material support that supports multiple base materials, filament cartridges, and paired holding parts. The filament cartridges each include multiple filaments (60), a first frame, a second frame, and paired connecting members. The paired holding parts guide each of the filament cartridges when it is inserted into the chamber, and hold the filament cartridges in the chamber so that the filament cartridges face the multiple base materials.

A first diamond layer made of polycrystalline diamonds and doped with foreign atoms, is arranged on a metal surface of a machining tool, and is used to detect the degree of wear of an undoped polycrystalline second diamond layer, which is arranged on the doped diamond layer and forms a functional region of the machining tool, wherein at least one physical parameter is detected continuously or periodically during operation of the tool, and wherein a change in the parameter indicates the degree of wear of the undoped second diamond layer. The doped diamond layer forms an “intelligent stop layer” for the tool because as a result of change in the transition from the undoped to the doped layer, the conductivity of the system changes, for example, and this change can be used to form a stop signal for the machine drive before the tool and the machined workpiece are damaged.

A self-supporting ultra-fine nanocrystalline diamond thick film, the thickness being 100-3000 microns, wherein 1 nanometer≤diamond grain size≤20 nanometers. A method for using chemical vapor deposition to grow ultra-fine nanocrystalline diamond on a silicon substrate, and separating the silicon substrate and the diamond to acquire the self-supporting ultra-fine nanocrystalline diamond thick film. The chemical vapor deposition method is simple and effective, and prepares a high-quality ultra-fine nanocrystalline diamond thick film.

Disclosed herein is system and method for protective diamond coatings. The method may include the steps of cleaning and seeding a substrate, depositing a crystalline diamond layer on the substrate, etching the substrate; and attaching the substrate to protected matter. The crystalline diamond layer may reflect at least 28 percent of electromagnetic energy in a beam having a bandwidth of 800 nanometer to 1 micrometer.

A method for synthesizing a diamond by chemical vapor deposition, the method may include heating at least one internal space of at least one hot filament unit; wherein the at least one hot filament unit is positioned in a vacuum chamber; wherein a volume of each internal space out of the at least one internal space is smaller than one half of a volume of the vacuum chamber; feeding at least one gas to the at least one internal space; wherein the at least one gas comprises at least a carbon carrier gas; breaking the at least one gas by the at least one hot filament unit, to provide at least one radical; and depositing the at least one radical on an area of a substrate to provide the diamond.

An ultra-fine nanocrystalline diamond precision cutting tool and a manufacturing method therefor. A diamond cutter is made of a thick self-supporting film of ultra-fine nanocrystalline diamond, the thick film having a thickness of 100-3000 microns, where 1 nanometer diamond grain size 520 nanometers. In the manufacturing method, the growth of ultra-fine nanocrystalline diamond on a silicon substrate is accomplished by means of two steps of direct current hot cathode glow discharge chemical vapor deposition and hot filament chemical vapor deposition, then the silicon substrate is separated from the diamond to obtain a thick self-supporting film of ultra-fine nanocrystalline diamond, the thick self-supporting film of ultra-fine nanocrystalline diamond is laser cut and then welded to a cutter body, and then by means of edging, rough grinding and fine grinding, an ultra-fine nanocrystalline diamond precision cutting tool is obtained.

A method of manufacturing a diamond substrate includes: forming an ion implantation layer at a side of a main surface of a diamond seed substrate by implanting ions into the main surface of the diamond seed substrate; producing a diamond structure by growing a diamond growth layer by a vapor phase synthesis method on the main surface of the diamond seed substrate, after implanting the ions; and performing heat treatment on the diamond structure. The performed heat treatment causes the diamond structure to be separated along the ion implantation layer into a first structure including the diamond seed substrate and failing to include the diamond growth layer, and a diamond substrate including the diamond growth layer. Thus, the method of manufacturing a diamond substrate is provided that enables a diamond substrate with a large area to be manufactured in a short time and at a low cost.