Abstract

An insulated investment casting shell mold is made by first mixing at least one refractory material with a slurry vehicle forming a prime coat slurry, and optionally mixing at least one refractory material with a slurry vehicle forming a backup slurry. The prime slurry is coated onto a fugitive pattern and optionally dried and / or stuccoed wherein the stucco has at least one refractory material. The backup and stucco may be applied a plurality of times to obtain a desired shell wall thickness. An insulating slurry is formed by introducing gas into a slurry vehicle having at least one refractory material and containing a stabilizer and a foaming agent, forming an insulating slurry having closed porosity therein. The insulating slurry is coated onto a portion of the pattern after the prime coat. At least a portion of the outermost layer of a backup coated pattern may have insulating slurry thereon.

IPC Classes  ?

• B22C 1/08 - Compositions of refractory mould or core materialsGrain structures thereofChemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives for decreasing shrinkage of the mould, e.g. for investment casting
• B22C 9/04 - Use of lost patterns