1 Mold casting processes Sand mold casting process Shell mold process Investment casting process Shaw process Full mold process [Shell mold casting] Centrifugal casting process Die casting process Vacuum casting process Low pressure casting process Squeeze casting process [Ceramic mold prepared through investment casting process] Technology of Application Cast Steel Automatic Engine Parts & Others [Parts of an automobile] [valve] [Defense Industry] Precision casting Wax pattern injection Tree assembly Wax Tree cleaning Shell mold coating Stucco coating Shell mold drying De-waxing Firing for shell mold Casting Remove fot shell mold and gate Heat-treatment Final product Shell mold coating Casting Ceramic mold prepared through investment casting process (a) Wax pattern (injection molding) (b) Multiple patterns assembled to wax sprue (c) Shell built immerse into ceramic slurry immerse into fine sand (few layers) (d) dry ceramic melt out the wax fire ceramic (burn wax) (e) Pour molten metal cool, solidify (f) Break ceramic shell (Vibration or water blasting) (g) Cut off parts (high-speed friction saw) finishing (polish) Sand mold process Mass production and simple process Use of organic binder with low degradation temperature - Blow-hall production - Low fracture under high temperature - Poor dimension stability - Environmental pollution Thick mold thickness Simple shape and thick product Convert mold process Mold process using inorganic binder Use of inorganic binder - Heat treatment (1000 ℃) - Better dimension stability - Better mechanical and thermal properties Enhancement of collapsibility Faster processing time High glassification efficiency - Enough fracture strength for thin-wall casting Development of new inorganic binder and new process Preparation of ceramic mold and core having high fracture strength in sand mold process Application into the precision casting Organic/Inorganic Hybrid Coating Advantages and drawbacks High fracture strength Easy processability Enhancement of collapse High thermal stability Low conversion ratio of inorganic precursor Loss of inorganic binder by the burning of organic binder Non-homogeneous coating of inorganic binder on the surface of stating particle New coating process Improvement the addition effect of inorganic precursor High glassification efficiency High dimension stability Enhancement of the mechanical and thermal properties Simple process Reaction mechanisms (1) Sol-gel reaction NaOMe + H2O MeOH + NaOH Sodium methoxide Methanol Sodium hydroxide nSi(OEt)4 + 4nH2O (n+ 1)SiO2 + 4nEtOH Tetraethyl orthosilicate Silica Ethanol (2) Glassification (Heat treatment) 2NaOH + SiO2 Na2O·SiO2 + H2O Sodium hydroxide Sodium silicate SiO2 precursors Silicate type w/o sol-gel reaction TEOS (Tetraethyl orthosilicate) Na2O precursor NaOMe(Sodium methoxide)
