A method of making a porous refractory article and a dispersion of particles in a liquid carrier, the method involving forming a dispersion of particles in a liquid carrier, introducing gas into the dispersion, removing the liquid carrier to provide a solid article having pores derived from the bubbles and wherein the dispersion has a critical viscosity below the level at which the introduction of gas cannot take place and above the level which entrapped gas bubbles will tend to escape and with the dispersion having the same critical viscosity.
A gas generating substance is added to an aqueous dispersion containing refractory particles and a polymerizable monomer and the pressure and/or temperature are adjusted so that the substance generates the gas before the polymerization gets underway; to control the formation of pores.
Porous zirconia or zirconium-containing particles, methods of making such particles and methods of using such particles including modifications to the surface of the particles are described. The method comprises heating zirconia particles to provide a substantially homogeneously liquid melt, quenching the particles of melt to effect spinodal decomposition to provide quench particles of a silica rich phase and a zirconia rich phase, annealing the quenched particles to provide non porous solid particles of zirconia and silica and, leaching the silica from these particles to produce porous solid zirconia particles comprising a three dimensionally substantially continuous inter penetrating network of interconnected pores.
Porous zirconia or zirconium-containing particles, methods of making such particles and methods of using such particles including modifications to the surface of the particles are described. The method comprises heating zirconia particles to provide a substantially homogeneously liquid melt, quenching the particles of melt to effect spinodal decomposition to provide quench particles of a silica rich phase and a zirconia rich phase, annealing the quenched particles to provide non porous solid particles of zirconia and silica and, leaching the silica from these particles to produce porous solid zirconia particles comprising a three dimensionally substantially continuous interpenetrating network of interconnected pores.
A fused silica production furnace and methods of producing fused silica are disclosed. The furnace and the methods involve using a foamed refractory having a network of interconnected pores.
A microabrasive tool is formed from a slurry including liquid, abrasive grains, a bonding material, and a polymer--for example, gellan gum. The slurry is cast in a mold, and the polymer is ionically cross-linked. Cross-linking the polymer fixes the structure of the bonding material and the abrasive grains, wherein the abrasive grains are dispersed substantially uniformly within the bonding material. The ionically cross-linked structure of bonding material and abrasive grains can then be fired to form a microabrasive tool.
