An environmental barrier coating, comprising a substrate containing silicon; an environmental barrier layer applied to said substrate; said environmental barrier layer comprising a rare earth composition.

A method for forming an isolating layer of a crucible includes placing a round crucible sideways with a bottom surface of an inside thereof perpendicular to a horizontal plane, and then performing a plurality of spraying processes to form the isolating layer on the bottom surface and a wall surface of the round crucible. Each spraying process includes spraying a slurry on the bottom surface; using an optical positioner to set a spraying range the same as one of a plurality of partial areas divided from the wall surface; aligning one of the plurality of partial areas with the spraying range; fixing the round crucible and spraying the slurry in the spraying range; stopping the spraying; and rotating the round crucible to move another partial area to the spraying range. Then, the steps are repeated until the spraying of all the partial areas is completed.

A method for forming an isolating layer of a crucible includes placing a round crucible sideways with a bottom surface of an inside thereof perpendicular to a horizontal plane, and then performing a plurality of spraying processes to form the isolating layer on the bottom surface and a wall surface of the round crucible. Each spraying process includes spraying a slurry on the bottom surface; using an optical positioner to set a spraying range the same as one of a plurality of partial areas divided from the wall surface; aligning one of the plurality of partial areas with the spraying range; fixing the round crucible and spraying the slurry in the spraying range; stopping the spraying; and rotating the round crucible to move another partial area to the spraying range. Then, the steps are repeated until the spraying of all the partial areas is completed.

A plurality of photocatalytic coated ceramic granules comprising base ceramic granules, each having an outer surface, and a photocatalytic coating disposed on the outer surface. The photocatalytic coating comprising an inorganic binder and a plurality of photocatalytic particles selected from TiO.sub.2, ZnO, Ti(OH).sub.4, doped derivatives thereof and combinations thereof. The photocatalytic particles have a surface area per weight of tire particles of no more than 30 square meters per gram (m.sup.2/g). The coated ceramic granules have a Total Solar Reflectance of at least 0.7.

An article includes a ceramic-based substrate and a barrier layer on the ceramic-based substrate. The barrier layer includes a matrix of barium-magnesium alumino-silicate or SiO.sub.2, a dispersion of silicon oxycarbide particles in the matrix, and a dispersion of particles, of the other of barium-magnesium alumino-silicate or SiO.sub.2, in the matrix.

An article includes a ceramic-based substrate and a barrier layer on the ceramic-based substrate. The barrier layer includes a matrix of barium-magnesium alumino-silicate or SiO.sub.2, a dispersion of silicon oxycarbide particles in the matrix, and a dispersion of particles, of the other of barium-magnesium alumino-silicate or SiO.sub.2, in the matrix.

A coating method includes depositing a slurry including a coarsely particulate ceramic and a finely particulate ceramic on a base material configured with an oxide-based ceramics matrix composite such that a proportion of coarse particles decreases towards a surface of the base material; forming a bond coating by performing a heat treatment on the base material on which the slurry has been deposited; and forming a top coating by thermally spraying a ceramic onto the bond coating. The oxide-based ceramics matrix composite is an alumina silica type oxide-based ceramics matrix composite. The coarsely particulate ceramic and the finely particulate ceramic are alumina-based powder.

A coating method includes depositing a slurry including a coarsely particulate ceramic and a finely particulate ceramic on a base material configured with an oxide-based ceramics matrix composite such that a proportion of coarse particles decreases towards a surface of the base material; forming a bond coating by performing a heat treatment on the base material on which the slurry has been deposited; and forming a top coating by thermally spraying a ceramic onto the bond coating. The oxide-based ceramics matrix composite is an alumina silica type oxide-based ceramics matrix composite. The coarsely particulate ceramic and the finely particulate ceramic are alumina-based powder.

Provided is a ZrO.sub.2—CaO—C based refractory material which is capable of maintaining high adhesion resistance over a long period of time, while exhibiting significant slaking resistance, and suppressing self-fluxing, i.e., exhibiting corrosion-erosion resistance. The refractory material comprises a CaO—ZrO.sub.2 composition containing a CaO component in an amount of 40% by mass to 60% by mass, wherein a mass ratio of the CaO component to a ZrO.sub.2 component is 0.67 to 1.5, and wherein the CaO—ZrO.sub.2 composition includes a eutectic microstructure of CaO crystals and CaZrO.sub.3 crystals, wherein a width of each of the CaO crystals observable in a cross-sectional microstructure is 50 μm or less.

Provided is a ZrO.sub.2—CaO—C based refractory material which is capable of maintaining high adhesion resistance over a long period of time, while exhibiting significant slaking resistance, and suppressing self-fluxing, i.e., exhibiting corrosion-erosion resistance. The refractory material comprises a CaO—ZrO.sub.2 composition containing a CaO component in an amount of 40% by mass to 60% by mass, wherein a mass ratio of the CaO component to a ZrO.sub.2 component is 0.67 to 1.5, and wherein the CaO—ZrO.sub.2 composition includes a eutectic microstructure of CaO crystals and CaZrO.sub.3 crystals, wherein a width of each of the CaO crystals observable in a cross-sectional microstructure is 50 μm or less.