Patent ID: 6287511
Filing Date: 2001-09-11
Classification: C04B

Abstract:
A method of manufacturing ceramic insulating bodies comprising the following steps:(a) mixing raw materials to form a viscous slurry, the raw materials comprising a phosphate binder and oxide filler powders; and then(b) adding a predetermined amount of hollow oxide-based spheres of various dimensions to the slurry to create a mixture such amount being effective such that each sphere in the bodies of Step (h) contacts at least one other sphere; and then(c) casting the mixture into presoaked molds; and then(d) allowing the castings, which have a viscosity, to dry; and then(e) removing, the castings from the molds when the viscosity of the castings is sufficiently high for ""green"" bodies to be extracted from the molds with minimal dimensional distortion; and then(f) transferring the ""green"" bodies to a drying oven and drying to remove free water; and then(g) transferring the ""green"" bodies to a firing oven; and then(h) firing the ""green"" bodies, evaporating the free water and thermally transforming the phosphate in the process, by the following steps:begin firing by slowly heating the firing oven to a temperature of approximately 250.degree. C.; andslowly increasing the temperature of the firing oven to a temperature of approximately 160.degree. C. to form a refractory phase of the phosphate; and then(i) machine finishing the fired bodies.