Refractory laminate based on negative sols or silicates and basic aluminum salts

Abstract

Abstract A RAPID PROCESS FOR FORMING A REFRACTORY LAMINATE ON THE SURFACE OF A SUPPORT STRUCTURE WHICH COMPRISES DIPPING THE STRUCTURE IN A BATH COMPRISING A SOL OF NEGATIVELY CHARGED COLLOIDAL PARTICLES OF AN INORGANIC SUBSTANCE AND/ OR A SOLUTION OF AN ALKALINE IONIC SILICATE TO FORM A COATING ON THE SURFACE, AND CONTACTING THE COATED SURFACE WITH A BASIC ALUMINUM SALT SETTING AGENT TO FIRMLY SET THE COLLODIAL SILICA OR SILICATE. THIS PROCEDURE IS REPEATED UNTIL A LAMINATE OF THE DESIRED THICKNESS IS BUILT UP ON THE SURFACE IN ORDER TO INCREASE THE RATE OF LAMINATE BUILT-UP PARTICULATE REFRACTORY MATERIAL CAN BE INCLUDED IN THE BATH AND/ OR THE COATED SURFACE CAN BE STUCCOED BETWEEN DIPS. INTERACTION BETWEEN OPPOSITELY CHARGED MATERIALS COMBINED WITH THE POLYMERIZATION OF THE ALUMINUM SPECIES IN THE PRESENCE OF BASE CAUSES AGGREGATION OF THE PARTICLES AND PRODUCES A STIFF GEL STRUCTURE. THESE EFFECTS RESULT IN THE IMMOBILIZATION OF THE COATINGS. THIS TECHNIQUE MAKES IT POSSIBLE TO SUCCESSIVELY APPLY AND SET COATINGS TO BUILD CERAMIC LAMINATES IN VARY SHORT TIMES WITHOUT INTERMEDIATE DRYING AND WITHOUT SLOUGHING OF COATS. THE PROCESS IS PARTICULARLY SUITED FOR MAKING EXPENDABLE, REFRACTORY SHELL MOLDS FOR PRECISION INVERSTMENT CASTING OF METALS BY THE SO-CALLED "LOST-WAX" TECHNIQUE.

Inventors

• 👤 E Moore

Bibliographic Details