Precision glass molds are described, which are formed by coating a mold made from high purity, fine grain sized graphite, with a coating including titanium. In various implementations, the titanium coating is overcoated with yttria (Y.sub.2O.sub.3) to provide a high precision glass mold of superior performance character. The resultant glass molds can be used to form glass articles having a highly smooth finish, for high precision applications such as consumer electronic device applications, medical instruments, and optical devices. The use of high purity, fine grain size graphite allows molds to be machined at low cost, thereby eliminating the need to fabricate a metal mold that must be coated with multiple layers including metal diffusion barrier layers to meet operational requirements for such precision applications.

Precision glass molds are described, which are formed by coating a mold made from high purity, fine grain sized graphite, with a coating including titanium. In various implementations, the titanium coating is overcoated with yttria (Y.sub.2O.sub.3) to provide a high precision glass mold of superior performance character. The resultant glass molds can be used to form glass articles having a highly smooth finish, for high precision applications such as consumer electronic device applications, medical instruments, and optical devices. The use of high purity, fine grain size graphite allows molds to be machined at low cost, thereby eliminating the need to fabricate a metal mold that must be coated with multiple layers including metal diffusion barrier layers to meet operational requirements for such precision applications.

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.

A UAV surface coating includes at least a bonding layer, an antioxidant layer, an oxygen-blocking propagation layer and a heat-insulation cooling layer. The coating is fabricated on a surface of a UAV machine body or covers on the surface of the UAV machine body through a composite material matrix. The UAV machine body is made of lightweight material, and the composite material matrix includes a resin-based composite matrix and a ceramic-based composite matrix. Wherein, a thickness of the bonding layer is from 20 ?m to 200 ?m, a thickness of the oxygen-blocking propagation layer is from 20 ?m to 200 ?m, and a thickness of the heat-insulation cooling layer is from 80 ?m to 1000 ?m.

A fiber comprises a bulk material comprising one or more materials selected from the group consisting of carbon, silicon, boron, silicon carbide, and boron nitride; and a metal whose affinity for oxygen is greater than the affinity for oxygen of any of the one or more materials. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium. At least a first portion of the metal may be present in un-oxidized form at the entrance to and/or within grain boundaries within the fiber.

A method of improving at least one of the strength, creep resistance, and toughness of a fiber comprises adding to a fiber, initially comprising a bulk material having a first affinity for oxygen, a metal that has a second affinity for oxygen higher than the first affinity. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium.

A fiber comprises a bulk material comprising one or more materials selected from the group consisting of carbon, silicon, boron, silicon carbide, and boron nitride; and a metal whose affinity for oxygen is greater than the affinity for oxygen of any of the one or more materials. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium. At least a first portion of the metal may be present in un-oxidized form at the entrance to and/or within grain boundaries within the fiber.

A method of improving at least one of the strength, creep resistance, and toughness of a fiber comprises adding to a fiber, initially comprising a bulk material having a first affinity for oxygen, a metal that has a second affinity for oxygen higher than the first affinity. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium.

An example method may include applying a bond coat comprising silicon or a silicon alloy on a surface of a ceramic or ceramic matrix composite substrate, where the bond coat comprises a plurality of pores; infiltrating a precursor into at least some pores of the plurality of pores; and heat-treating the bond coat and the precursor, where after heat-treating a porosity of the bond coat is less than about 5 vol. %, and where after heat-treating, the bond coat is substantially free of continuous porosity extending through a thickness of the bond coat.

An example method may include applying a bond coat comprising silicon or a silicon alloy on a surface of a ceramic or ceramic matrix composite substrate, where the bond coat comprises a plurality of pores; infiltrating a precursor into at least some pores of the plurality of pores; and heat-treating the bond coat and the precursor, where after heat-treating a porosity of the bond coat is less than about 5 vol. %, and where after heat-treating, the bond coat is substantially free of continuous porosity extending through a thickness of the bond coat.

Disclosed is a faucet valve including: a first valve body including a first slide surface, and formed from an alumina-based sintered body; and a second valve body including a second slide surface, and formed from an alumina-based sintered body, the first and second slide surfaces at least partially being in contact with each other with water in between. At least part of the second slide body is formed from a first amorphous carbon layer. The hardness of the first amorphous carbon layer is equal to or less than that of the alumina-based sintered body forming the first valve body. In the first amorphous carbon layer, a ratio (ID/IG) of a D peak to a G peak, measured by Raman spectroscopy, is greater than 0.5 but less than 1.9.

Disclosed is a faucet valve including: a first valve body including a first slide surface, and formed from an alumina-based sintered body; and a second valve body including a second slide surface, and formed from an alumina-based sintered body, the first and second slide surfaces at least partially being in contact with each other with water in between. At least part of the second slide body is formed from a first amorphous carbon layer. The hardness of the first amorphous carbon layer is equal to or less than that of the alumina-based sintered body forming the first valve body. In the first amorphous carbon layer, a ratio (ID/IG) of a D peak to a G peak, measured by Raman spectroscopy, is greater than 0.5 but less than 1.9.