Development of a nucleation inhibitive coated mold for the rapid solidification of superalloy melt

The development of a glass-lined mold from gels in the ternary system of SiO2-ZrO2-B2O3 by adopting the shell molding technique and sol-gel processing has been investigated. The crystallization characteristics of ZrO2 particles and the high temperature structure stability of Si-Zr-B coating were demonstrated. The inhibitive effect of B2O3 on crystallization in the Si-Zr-B coating was explained. Finally, the result that DD3 single crystal superalloy can obtain high undercooling and realize rapid solidification in it establishes that the Si-Zr-B coated mold has an ideal non-catalytic nucleation inhibition for superalloy melt. (C) 2002 Elsevier Science B.V. All rights reserved.