7 results about "Highly oriented pyrolytic graphite" patented technology

The embodiment of the invention discloses a preparation method of a high-purity large-size hexagonal diamond, which comprises the following steps: S1, cutting along the c axis of highly oriented pyrolytic graphite to obtain cylindrical highly oriented pyrolytic graphite as a raw material precursor; s2, assembling the raw material precursor in a high-pressure heating synthesis assembly; s3, the high-pressure heating synthesis assembly is heated and pressurized to set pressure and set temperature, heat preservation is conducted for set time, and the high-purity hexagonal diamond is obtained; wherein the set temperature ranges from 1300 DEG C to 1900 DEG C, the set pressure ranges from 20 GPa to 25 GPa, and the set time ranges from 10 min to 20 min. According to the preparation method of the high-purity large-size hexagonal diamond disclosed by the embodiment of the invention, cylindrical high-orientation pyrolytic graphite cut along a c axis is used as a raw material precursor, the high-orientation pyrolytic graphite is completely converted into the high-purity large-size hexagonal diamond under set conditions, and the size is 1-2 mm; the method has important application prospects in the fields of superhard materials, semiconductor devices and the like.

Methods and systems for fabricating an electrical conductor on a substrate are disclosed. A method of manufacturing an electrical conductor on a substrate by cold spraying includes propelling a solid powder composition including copper and highly oriented pyrolytic graphite using a gaseous propellant, and directing the solid powder composition to the substrate at a velocity sufficient to cause the solid powder composition to undergo plastic deformation and adhere to the substrate to deposit the electrical conductor thereon.

The invention discloses a carbon material, a preparation method and application thereof, and belongs to the field of carbon materials. The carbon material is hard carbon, and the carbon vacancy of the carbon material is 0.11-0.58; the relational expression of the carbon vacancy tau is defined as # imgabs0 #, and IGC is the density of carbon atoms existing in the highly oriented pyrolytic graphite in the form of SP2 hybrid carbon atom pairs; iHC is the density of carbon atoms present as SP2 hybrid carbon atom pairs in the hard carbon material. The carbon material is obtained through the steps of high-temperature hot isostatic pressing sintering, oxygen plasma etching ball milling, sintering carbonization in a kiln and the like. The carbon material with a specific carbon vacancy ratio is defined, the carbon material has excellent sodium storage performance, and a new negative electrode material selection and a technical breakthrough point are provided for sodium ion battery industrialization.

This invention relates to a method for preparing biomimetic diamonds with shell-like structures, aiming to effectively enhance the toughness of superhard materials. Using highly oriented pyrolytic graphite as raw material, a high-temperature, high-pressure method was employed to manipulate the sample's microstructure and graphite content, resulting in the successful preparation of biomimetic diamonds with a shell-like nacreous structure. This method bends the highly oriented graphite under high pressure to replicate the cross-interlocking structure found in shells, while simultaneously utilizing the martensitic phase transformation properties of graphite to control the diamond grain orientation. Experimental results indicate that the biomimetic diamonds produced exhibit extremely high hardness (HV > 120 GPa) and excellent toughness (K IC =15.9 MPa·m 0.5 ), with toughness approximately four times that of single-crystal diamond. Compared to traditional nano-polycrystalline diamond (NPD), its toughness is nearly doubled while maintaining similar hardness. This invention resolves the contradiction between hardness and toughness in superhard materials, providing a new technical path for the application of extremely hard and high-toughness NPD, and has important industrial application prospects.

The invention relates to a preparation method of bionic diamond with a shell-like structure, and aims to effectively improve the toughness of a superhard material. According to the method, highly oriented pyrolytic graphite is taken as a raw material, a microstructure and graphite content in a sample are regulated and controlled by adopting a high-temperature and high-pressure method, and the bionic diamond with a shell-pearl-mother-like structure is successfully prepared. According to the method, highly oriented graphite is bent under high pressure, a cross interlocking structure in a shell is reproduced, meanwhile, the grain orientation of the diamond is controlled by utilizing the martensite phase transformation characteristic of the graphite, and experiments show that the prepared bionic diamond has extremely high hardness (HVgt; compared with the traditional nano polycrystalline diamond (NPD), the prepared nano polycrystalline diamond has the advantages that the prepared nano polycrystalline diamond has excellent toughness (KIC = 15.9 MPa.m < 0.5 >) and excellent toughness (KIC = 15.9 MPa.m < 0.5 >), the toughness of the nano polycrystalline diamond is about 4 times that of single crystal diamond, and the toughness of the nano polycrystalline diamond is nearly doubled under the condition of keeping similar hardness compared with the traditional nano polycrystalline diamond (NPD). According to the invention, the contradiction between hardness and toughness in the superhard material is solved, a new technical path is provided for the application of the superhard high-toughness NPD, and the superhard high-toughness NPD has important industrial application prospects.

This invention provides a method for preparing ultra-smooth, wrinkle-free graphene films, belonging to the field of graphene film preparation technology. The method includes: smoothing the surface of a highly oriented pyrolytic graphite substrate; depositing a copper or nickel atomic layer on the substrate surface by electron beam evaporation; forming an atomically smooth copper or nickel surface by high-temperature treatment of the copper or nickel atomic layer; using a gaseous carbon source, growing a wrinkle-free monolayer graphene film on the atomically smooth copper surface via chemical vapor deposition; or using highly oriented pyrolytic graphite as a solid carbon source, growing a wrinkle-free multilayer graphene film on an atomically smooth nickel surface via a carbon dissolution-precipitation method. This invention solves the technical problem of wrinkle defects that may occur when using existing CVD methods to prepare graphene films.

The present disclosure provides a neutron generating target that includes a neutron generating region, a highly thermally conductive base plate substrate, and an intermediate layer positioned between the neutron generating region and the substrate to facilitate heat transfer and / or avoid hydrogen deposition in the substrate. One example of the intermediate layer is highly oriented pyrolytic graphite. The present disclosure provides, among other things, a lithium-containing neutron generating target useful for generating a neutron beam for irradiating boron-containing compounds in boron neutron capture therapy ("BNCT") of cancer.