An alumina having a multimodal particle size distribution wherein at least one of the particle sizes giving local maximum values in the particle size distribution is less than 10 m, and wherein the alumina comprises 1 to 5 wt % of at least one of La and Ba.

Alumina products containing a fine particle size component and a coarse particle size component, and with specific particle size characteristics and irregular and non-spherical particle shapes, are disclosed. These alumina products can be used in polymer formulations to produce composites having high isotropic thermal conductivity.

A hydrophobic coating and a method for applying such a coating to a surface of a metallic substrate. The method can include anodizing a nanoporous layer of anodic metal oxide on the surface; cathodizing yttrium oxide nanoparticles onto the surface; applying a hydrophobic ceramic coating composition to the surface by an application method selected from the group consisting of: flowing, dipping, and spraying; and heating the coated surface at a cure temperature from about 150 C. to about 300 C. for at least 2 hours.

To provide: an inorganic oxide powder which, when filled in a resin material, can simultaneously achieve a high dielectric constant and a low dielectric dissipation factor; a method for producing the same; and a resin composition comprising the inorganic oxide powder.

Provided is an inorganic oxide powder comprising a spherical titanium oxide powder and an aluminum oxide powder, wherein the aluminum content in the inorganic oxide powder is 20-50,000 mass ppm. Further provided is a resin composition comprising the inorganic oxide powder and at least one resin material selected from a thermoplastic resin and a thermosetting resin.

To provide: an inorganic oxide powder which, when filled in a resin material, can simultaneously achieve a high dielectric constant and a low dielectric dissipation factor; a method for producing the same; and a resin composition comprising the inorganic oxide powder.

Provided is an inorganic oxide powder comprising a spherical titanium oxide powder and an aluminum oxide powder, wherein the aluminum content in the inorganic oxide powder is 20-50,000 mass ppm. Further provided is a resin composition comprising the inorganic oxide powder and at least one resin material selected from a thermoplastic resin and a thermosetting resin.

A method for manufacturing a fused metal sight window that melts the metal of the frame around the window, instead of the traditional method of melting the window into the frame. Since most of the superior optical transparent materials (such as fused silica, sapphire, YAG, ALON, diamond, fused quartz and magnesium fluoride) have a melting point higher than most metals, it was not previously possible to create fused metal sight windows with these materials. By melting the frame onto the window, many new combinations of metals and optical materials may be used while retaining the strength of the sight window that results from fusing the metal and the window.

A method for manufacturing a fused metal sight window that melts the metal of the frame around the window, instead of the traditional method of melting the window into the frame. Since most of the superior optical transparent materials (such as fused silica, sapphire, YAG, ALON, diamond, fused quartz and magnesium fluoride) have a melting point higher than most metals, it was not previously possible to create fused metal sight windows with these materials. By melting the frame onto the window, many new combinations of metals and optical materials may be used while retaining the strength of the sight window that results from fusing the metal and the window.

The present disclosure provides a preparation method of spherical ?-alumina with a low viscosity and a high thermal conductivity. In the preparation method, a spherical ?-alumina powder is obtained through spheroidization by melting using an angular ?-alumina powder as a raw material; and the spherical ?-alumina powder is calcined at a high temperature to obtain the spherical ?-alumina with a low viscosity and a high thermal conductivity. In the present disclosure, a spheroidization rate and an ?-phase are kept unchanged by adjusting a calcination temperature and a calcination time, while improving the thermal conductivity of the alumina and not affecting a viscosity of products such as thermal conductive films prepared from the alumina as a filler.

The present disclosure provides a preparation method of spherical ?-alumina with a low viscosity and a high thermal conductivity. In the preparation method, a spherical ?-alumina powder is obtained through spheroidization by melting using an angular ?-alumina powder as a raw material; and the spherical ?-alumina powder is calcined at a high temperature to obtain the spherical ?-alumina with a low viscosity and a high thermal conductivity. In the present disclosure, a spheroidization rate and an ?-phase are kept unchanged by adjusting a calcination temperature and a calcination time, while improving the thermal conductivity of the alumina and not affecting a viscosity of products such as thermal conductive films prepared from the alumina as a filler.

A method comprising: spraying a ceramic coating to a substrate to a thickness of at least 5.0 mils (127 micrometers) without quench; and after the spraying, directing a carbon dioxide flow to a surface of the coating.