The present invention discloses a polyimide-based composite carbon film with high thermal conductivity and a preparation method therefor. The preparation method includes: uniformly coating the surface of a polyimide-based carbon film with an aqueous graphene oxide solution, and then covering the same with another polyimide-based carbon film uniformly coated with an aqueous graphene oxide solution; repeating such operation; after the polyimide-based carbon films are dried, bonding the polyimide-based carbon films by means of graphene oxide so as to form a thick film; bonding the polyimide-based carbon films more tightly by means of further low-temperature hot pressing; and finally, obtaining a thick polyimide-based carbon film with high thermal conductivity by repairing defects by means of low-temperature heating pre-reduction and high-temperature and high-pressure thermal treatment. The thick polyimide-based carbon film with high thermal conductivity has a thickness greater than 100 m and an in-plane thermal conductivity of even reaching 1700 W/mK or above.

A super hard polycrystalline construction has a first region having a body of thermally stable polycrystalline super hard material with an exposed surface forming a working surface, and a peripheral side edge, a second region forming a substrate to the first region and a third region interposed between the first and second regions. The third region extends across a surface of the second region along an interface and has a composite material having a first phase comprising a plurality of non-intergrown diamond grains, the majority of the diamond grains having a coating comprising nano-sized BN particles. There is also disclosed a method of making such a construction.

Vessels selected from crucibles, pans, open cups and saggars essentially comprising of two components, from which (A) one component being a ceramic matrix composite, and (B) the second component being from metal or alloy, and wherein component (A) is the inner one.

A superhard polycrystalline construction comprises a body of polycrystalline superhard material comprising a structure comprising superhard material, the structure having porosity greater than 20% by volume and up to around 80% by volume. A method of forming such a superhard polycrystalline construction comprises forming a skeleton structure of a first material having a plurality of voids, at least partially filling some or all of the voids with a second material to form a pre-sinter assembly, and treating the pre-sinter assembly to sinter together grains of superhard material to form a body of polycrystalline superhard material comprising a first region of superhard grains, and an interpenetrating second region; the second region being formed of the other of the first or second material that does not comprise the superhard grains; the superhard grains forming a sintered structure having a porosity greater than 20% by volume and up to around 80% by volume.

It is an object of the present disclosure to provide a thin-film carbon foam and a method of manufacture the same. It is another object of the present disclosure to provide a stack carbon foam having fewer through holes and a method of manufacturing the same. The carbon foam of the present disclosure is, for example, a stack carbon foam being a stack of at least two monolayer carbon foams stacked one another, each monolayer carbon foam comprising linear portions and node portions joining the linear portions, or a carbon foam comprising linear portions and node portions joining the linear portions, wherein the ratio of the number of large through holes having a diameter of 1 mm or more to the surface area of the carbon foam is 0.0003/mm.sup.2 or less.

Chemical methods, optionally in combination with physical methods, may be used to increase the strength of the bond formed by a braze material between a polycrystalline material and a hard composite. Such polycrystalline materials brazed to hard composites may be found in various wellbore tools include drill bit cutters. An exemplary method may include forming a bonding layer on a bonding surface of a polycrystalline material body that comprises a hard material, the bonding surface opposing a contact surface of the polycrystalline material body, and the bonding layer substantially formed by a [111] crystal structure of the hard material, a [100] crystal structure of the hard material, or a combination thereof; and brazing the bonding layer to a hard composite using a braze material.

An interconnected corrugated carbon-based network comprising a plurality of expanded and interconnected carbon layers is disclosed. In one embodiment, each of the expanded and interconnected carbon layers is made up of at least one corrugated carbon sheet that is one atom thick. In another embodiment, each of the expanded and interconnected carbon layers is made up of a plurality of corrugated carbon sheets that are each one atom thick. The interconnected corrugated carbon-based network is characterized by a high surface area with highly tunable electrical conductivity and electrochemical properties.

Embodiments of the invention relate to polycrystalline diamond (PCD) exhibiting enhanced diamond-to-diamond bonding. In an embodiment, PCD includes a plurality of diamond grains defining a plurality of interstitial regions. A metal-solvent catalyst occupies at least a portion of the plurality of interstitial regions. The plurality of diamond grains and the metal-solvent catalyst collectively exhibit a coercivity of about 115 Oersteds (Oe) or more and a specific magnetic saturation of about 15 Gauss.Math.cm.sup.3/grams (G.Math.cm.sup.3/g) or less. Other embodiments are directed to polycrystalline diamond compacts (PDCs) employing such PCD, methods of forming PCD and PDCs, and various applications for such PCD and PDCs in rotary drill bits, bearing apparatuses, and wire-drawing dies.

A method for producing a component includes a) providing at least two preforms each made of a carbon composite material, b) joining the at least two preforms at least at one respective connecting surface to form a composite, in which a joining compound is introduced between the joining surfaces of the preforms and then cured and the joining compound contains silicon carbide and at least one polymer adhesive, and c) siliconizing the composite to form the component. A component, such as an optical component produced thereby, is also provided.

A novel composite diamond film comprising of a relatively thick layer of UNCD (Ultrananocrystalline Diamond) with a Young's modulus of less than 900 GPa and a relatively thin MCD (microcrystalline diamond) outermost layer with a Young's modulus of greater than 900 GPa, has been shown to exhibit superior delamination resistance under extreme shear stress. It is hypothesized that this improvement is due to a combination of stress relief by the composite film with a slightly softer UNCD layer, a disruption of the fracture mechanism through the composite layer(s), and the near ideal chemical and thermal expansion coefficient match between the two diamond layers. The combination of a thick but softer underlying UNCD layer with a thin but harder overlying MCD layer provides an excellent compromise between the low deposition cost and smoothness of UNCD with the extreme hardness and unparalleled chemical, electrochemical and immunological inertness of even a thin layer of MCD. The MCD layer's roughness is minimized and its adhesion maximized by the use of a thin layer of MCD and its deposition on the smooth surface of the chemically nearly identical underlying UNCD layer. The composite film can be applied to any application currently utilizing a diamond or a similar hard film, including cutting tools, abrasive surfaces, electrochemistry, biomedical applications such as human implants or thermally conductive films and the like, requiring superior durability, chemical resistance and/or immunological inertness.