An uncalcined geopolymer-based refractory material is provided, comprising a matrix of a geopolymer obtainable by polymerization of a mixture consisting of mineral powder, fly ash, and metakaolin; and SiC whiskers embedded in the geopolymer matrix. The material has excellent mechanical properties and high resistance to high temperatures and exhibits a ductile fracture mechanism instead of a brittle fracture mechanism.

An uncalcined geopolymer-based refractory material is provided, comprising a matrix of a geopolymer obtainable by polymerization of a mixture consisting of mineral powder, fly ash, and metakaolin; and SiC whiskers embedded in the geopolymer matrix. The material has excellent mechanical properties and high resistance to high temperatures and exhibits a ductile fracture mechanism instead of a brittle fracture mechanism.

A method of making a composition of matter comprising calcium hydroxide. The method includes the steps of contacting a calcium-containing molecule with an aqueous solution of a water-soluble salt having ammonium cation and a counter-anion, under conditions effective to yield a compound containing calcium and the counter-anion; and reacting the compound comprising calcium and the counter-anion with ammonia and water under conditions to yield calcium hydroxide.

A heat resistant countertop or a heat resistant three dimensional shape product comprising a composition comprising at least one aggregate, at least one cement, at least one fine material, at least one dispersant, and at least one viscosity modifier, and optionally at least one set retarder, and optionally at least one set accelerator. A heat resistant countertop or a heat resistant three dimensional shape product comprising a calcium aluminate cement hydraulic binder and matrix is provided.

A heat resistant countertop or a heat resistant three dimensional shape product comprising a composition comprising at least one aggregate, at least one cement, at least one fine material, at least one dispersant, and at least one viscosity modifier, and optionally at least one set retarder, and optionally at least one set accelerator. A heat resistant countertop or a heat resistant three dimensional shape product comprising a calcium aluminate cement hydraulic binder and matrix is provided.

An article includes a substrate and a barrier layer on the substrate. The barrier layer includes a matrix, diffusive particles dispersed in the matrix, and gettering particles dispersed in the matrix. The gettering particles include at least one alloyed metal silicide. A composite material and a method of fabricating an article are also disclosed.

An article includes a substrate and a barrier layer on the substrate. The barrier layer includes a matrix, diffusive particles dispersed in the matrix, and gettering particles dispersed in the matrix. The gettering particles include at least one alloyed metal silicide. A composite material and a method of fabricating an article are also disclosed.

A zirconia material manufacturing method includes: dispersing hydroxyapatite powder in water to prepare a slurry having a hydroxyapatite powder concentration of 1%; and dipping zirconia in the slurry to form, on the zirconia, a coating layer containing hydroxyapatite.

A zirconia material manufacturing method includes: dispersing hydroxyapatite powder in water to prepare a slurry having a hydroxyapatite powder concentration of 1%; and dipping zirconia in the slurry to form, on the zirconia, a coating layer containing hydroxyapatite.

An article has a substrate and a layer atop the substrate. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS).