The traditional water-glass sand type has disadvantages of low recycling rate

poor storage stability and serious environmental pollution. A combination of selective laser sintering and impregnation reinforcement technology was adopted to develop a graphite ceramic composite type with low thermal conductivity and high strength

intending to replace the water-glass sand type and reduce the environmental pressure. The graphite-ceramic composite type was designed based on a theoretical model of tandem thermal conductivity

and the relationship between different functional layer thicknesses and thermal conductivity coefficient were determined. The effects of graphite/phenolic resin hybrid powder composition and silica-sol impregnation reinforcement process were investigated on the thermal conductivity coefficient and compressive strength of the sparse thermal insulation layer and the impregnation reinforced layer. Finally

graphite-ceramic composite types with thermal conductivity coefficient less than 2 W/（m·K） and compressive strength higher than 10 MPa were rapidly prepared

and pouring was conducted

verifying the feasibility of replacing water-glass sand types with graphite-ceramic composite types.