Patent ID: 6013125
Filing Date: 2000-01-11
Classification: A61C,B22C,C04B

Abstract:
An improved investment powder for use in making molds for casting metals at a selected mold casing temperature range, said temperature range being no greater than casting temperature of the metal being cast, said powder including gypsum and, at least, one form of silica, said powder being improved by the use of at least one water soluble oxidizing agent selected from the group consisting of KNO.sub.3, Ca(NO.sub.3).sub.2, LiNO.sub.3, Fe (NO.sub.3).sub.2, NaNO.sub.2, Ni(NO.sub.3).sub.2, Cu(NO.sub.3).sub.2, Al(NO.sub.3).sub.2, NH.sub.4 NO.sub.3 and Mg (NO.sub.3).sub.2 and present at 1/2-10% of said powder, where, when heated, said oxidizing agent releases oxygen at temperatures below said selected mold casting temperature range and said release of oxygen allows elimination of water wax and residual carbon present in said mold at said temperature range.