A method of manufacturing a concrete product includes providing a metal-based cementing agent including at least one of Fe.sub.2O.sub.3 and Fe.sub.3O.sub.4, an aqueous phosphoric acid cement reacting agent, an aggregate having at least one metallic oxide, a setting agent including at least one of Fe.sup.+2 and Mn.sup.+2, and an acid scavenging agent including at least one of K-feldspar and magnesium silicate. The method includes mixing the metal-based cementing agent, the cement reacting agent, the aggregate, the setting agent and the acid scavenging agent together to form a liquid concrete mixture, and placing the liquid concrete mixture in a form and allowing the liquid concrete mixture to set up and cure into the concrete product. The method can optionally include the additional step of placing the concrete product into an oven at a temperature of between 170 and 190 C.

A method of processing a polycrystalline diamond element may include providing a protective leaching cup having a rear wall, an opening defined by a portion of the protective leaching cup opposite the rear wall, and a side wall extending between the opening and the rear wall, the side wall and the rear wall defining a cavity within the protective leaching cup. The method may further include positioning a polycrystalline diamond element in the cavity defined within the protective leaching cup. Positioning the polycrystalline diamond element in the cavity may include expanding at least a portion of the opening outward from a center of the opening. The method may additionally include exposing at least a portion of the polycrystalline diamond element to a leaching agent.

Disclosed herein is an environmentally safe etching composition and method for a concrete or mortar surface. The composition includes, in some embodiments, an aqueous solution of urea, acetic acid, a buffering agent, an anticorrosive agent, and a surfactant with no more than about 30% (w/v) urea and at least about 10% (v/v) acetic acid. The method includes, in some embodiments, obtaining the etching composition; applying the etching composition to the concrete or mortar surface at a prescribed ratio of the etching composition to the concrete or mortar surface; allowing the etching composition to stand on the concrete or mortar surface for a prescribed amount of time; and washing the concrete or mortar surface with water to produce an etched surface of the concrete or mortar.

A method for forming a protective coating on a surface of a ceramic substrate includes combining a rare-earth oxide, alumina, and silica to form a powder, etching the surface of the ceramic substrate, applying the powder on the etched surface in an amount of from about 0.001 to about 0.1 g/cm.sup.2 to reduce capture of bubbles from off-gassing of the ceramic substrate, heating the powder for a time of from about 5 to about 60 minutes to a temperature at or above the melting point such that the powder melts and forms a molten coating on the surface that has a minimized number of bubbles, and cooling the molten coating to ambient temperature to form the protective coating disposed on and in direct contact with the surface of the ceramic substrate such that the protective coating has a thickness of less than about 1 mil.

A method for forming a protective coating on a surface of a ceramic substrate includes combining a rare-earth oxide, alumina, and silica to form a powder, etching the surface of the ceramic substrate, applying the powder on the etched surface in an amount of from about 0.001 to about 0.1 g/cm.sup.2 to reduce capture of bubbles from off-gassing of the ceramic substrate, heating the powder for a time of from about 5 to about 60 minutes to a temperature at or above the melting point such that the powder melts and forms a molten coating on the surface that has a minimized number of bubbles, and cooling the molten coating to ambient temperature to form the protective coating disposed on and in direct contact with the surface of the ceramic substrate such that the protective coating has a thickness of less than about 1 mil.

Methods for forming sintered-bonded high temperature coatings over ceramic turbomachine components are provided, as are ceramic turbomachine components having such high temperature coatings formed thereover. In one embodiment, the method includes the step or process of removing a surface oxide layer from the ceramic component body of a turbomachine component to expose a treated surface of the ceramic component body. A first layer of coating precursor material, which has a solids content composed predominately of at least one rare earth silicate by weight percentage, is applied to the treated surface. The first layer of the coating precursor material is then heat treated to sinter the solids content and form a first sintered coating layer bonded to the treated surface. The steps of applying and sintering the coating precursor may be repeated, as desired, to build a sintered coating body to a desired thickness over the ceramic component body.

Methods for forming sintered-bonded high temperature coatings over ceramic turbomachine components are provided, as are ceramic turbomachine components having such high temperature coatings formed thereover. In one embodiment, the method includes the step or process of removing a surface oxide layer from the ceramic component body of a turbomachine component to expose a treated surface of the ceramic component body. A first layer of coating precursor material, which has a solids content composed predominately of at least one rare earth silicate by weight percentage, is applied to the treated surface. The first layer of the coating precursor material is then heat treated to sinter the solids content and form a first sintered coating layer bonded to the treated surface. The steps of applying and sintering the coating precursor may be repeated, as desired, to build a sintered coating body to a desired thickness over the ceramic component body.

A dental article including a dental article body made of a ceramic material and a coating formed on the surface of said dental article body. The coating includes crystalline nanostructures made of yttria-stabilized zirconia YSZ.sub.1, the crystal habitus of at least a portion of the nanostructures having at least approximately the shape of a regular convex polyhedron.

A dental article including a dental article body made of a ceramic material and a coating formed on the surface of said dental article body. The coating includes crystalline nanostructures made of yttria-stabilized zirconia YSZ.sub.1, the crystal habitus of at least a portion of the nanostructures having at least approximately the shape of a regular convex polyhedron.

An aqueous modified acid composition for industrial activities, said composition comprising: an alkanolamine and strong acid in a molar ratio of not less than 1:15, preferably not less than 1:10; it can also further comprise a metal iodide or iodate. Said composition demonstrates advantages over known conventional acids and modified acids.