Hexavalent chromium-free slurry formulations which are suitable in the production of ceramic overlay coating systems are described. The formulations provide superior hot corrosion and heat oxidation protection for superalloy substrates. A basecoat slurry and topcoat slurry are provided. The basecoat slurry includes an aluminum phosphate based aqueous solution having a molar ratio of Al:PO.sub.4 higher than about 1:3 with the incorporation of metal oxide particles. The topcoat slurry includes an aluminum phosphate based aqueous solution having a molar ratio of Al:PO.sub.4 higher than about 1:3. Both of the basecoat slurry and the topcoat slurry are hexavalent chromium-free.

Hexavalent chromium-free slurries are provided that are capable of achieving a full cure at temperatures as low as 330-450 degrees F., thus making the coatings especially suitable for application on temperature sensitive base materials. The slurries are suitable in the production of protective coating systems formed by novel silicate-based basecoats that are sealed with novel phosphate-based topcoats. The coating systems exhibit acceptable corrosion and heat resistance and are capable of replacing traditional chromate-containing coating systems.

Disclosed are a lightweight conductive mortar material, a preparation method therefor and use thereof. The lightweight conductive mortar material includes the following components in parts by weight: 100 parts of cement, 25 parts to 60 parts of a conductive porous lightweight aggregate loaded with a modified agar gel, and 30 parts to 45 parts of water.

This disclosure relates to compositions for protecting a metallic surface susceptible to corrosion, the composition comprising a first component comprising an aqueous mixture of an acid-phosphate of chemical formula A.sup.m(H.sub.2PO.sub.4).sub.m.nH.sub.2O, where A is hydrogen ion, ammonium cation, metal cation, or mixtures thereof where m=1-3, and n=0-6; the first component solution adjusted to a pH of about 2 to about 5, the first component having a particle size distribution between 0.04 to 60 micron; and a second component, configured for combination and at least partial reaction with the first component to provide a phosphate ceramic, the second component comprising an aqueous solution or suspension of an alkaline oxide or alkaline hydroxide represented by B.sup.2mO.sub.m, B(OH).sub.2m, or mixtures thereof, where B is an element of valency 2m (m=1, 1.5, or 2) the second component solution adjusted to a pH of between 9-14.

A composition for coating stainless steel includes sodium silicate, lithium silicate, sodium tetraborate, and a solvent as the remainder so that a contaminant on the surface of stainless steel is easily removed and yellowing of the stainless steel can be prevented. A cooking appliance includes the stainless steel surface coated with the composition.

A method for preparing aerogel particles and a coated component are provided. The coated component includes a substrate and a coating. The coating includes aerogel particles sprayed from a hot gas jet or plasma jet. The method includes the step of feeding one or a plurality of gel particles into a hot gas jet or plasma j et. The one or a plurality of gel particles are sufficiently small to permit supercritical drying during the time the particles are in the jet. The method further includes the step of exposing the one or a plurality of gel particles to the temperatures and pressures of the hot gas jet or plasma jet to create the aerogel particles outside of a jet emitter and/or without a sealed pressure vessel.

The present invention relates generally to silicate-based coatings and to methods to make and apply same. In one embodiment, the silicate-coatings of the present invention are formed from a two part mixture of phosphate-based component and a glass-based component. In another embodiment, the silicate-based coatings of the present invention are free from any organic materials.

A composition consisting essentially of (a) 1 to 30 wt. % of a hydrogen phosphate selected from the group consisting of mono and dihydrogen phosphates of sodium, potassium, ammonium, magnesium, calcium, aluminium, zinc, iron, cobalt, and copper; (b) 1 to 40 wt. % of a compound selected from the group consisting of oxides, hydroxides, and oxide hydrates of magnesium, calcium, iron, zinc, and copper; (c) 40 to 95 wt. % of a particulate filler selected from the group consisting of glass; mono-, oligo- and poly-phosphates of magnesium, calcium, barium and aluminium; calcium sulfate; barium sulfate; simple and complex silicates; simple and complex aluminates; simple and complex titanates; simple and complex zirconates; zirconium dioxide; titanium dioxide; aluminium oxide; silicon dioxide; silicon carbide; aluminium nitride; boron nitride and silicon nitride; and (d) 0 to 25 wt. % of a constituent that differs from constituents (a) to (c).

A method includes forming a ceramic member that has a plurality of closed pores within a ceramic matrix. The forming includes compacting a ceramic powder to form intra-particle pores between particles of the ceramic powder, and sintering the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix. The diffusion does not fill the intra-particle pores and leaves the closed pores.

Joint compounds and spackling compounds which comprise a sanding indicator, the compounds displaying a first color at the surface upon drying/hardening. Methods for finishing a substrate or patching a substrate, the methods comprise applying the joint compound which comprises the sanding indicator and/or the spackling compound which comprises the sanding indicator and sanding the dried/hardened compound until the first color is removed. Accessory products which comprise at least one sanding indicator and methods for making joint compounds and spackling compounds comprising the sanding indicator.