Mullite powder is widely used in the casting process. The following are its specific applications and advantages in different casting processes:

I. Investment casting

Mullite powder is an important refractory material in investment casting, which is mainly used to make the surface layer and back layer of shell. Its high refractoriness (up to 1750~2000℃) and low expansion coefficient can effectively reduce the deformation and cracks of castings. In addition, the fine particles of mullite powder can improve the surface smoothness of the mold shell, thus improving the surface quality of the casting.

II. V molding and vacuum suction casting

Mullite powder is used as gypsum filler in V molding and vacuum suction casting to enhance the high temperature stability of molding materials. Its excellent high-temperature performance and chemical stability can ensure the structural stability of the mold in high-temperature environment and reduce the casting defects caused by thermal expansion.

III. Coating for cast steel

Mullite powder is widely used in the preparation of paste coatings for cast steel because of its chemical inertness and no chemical reaction with molten steel. This coating can effectively prevent the oxidation and pollution of the casting surface and improve the purity of the casting.

IV. Manufacture of ceramic cores

Mullite powder can be used to make ceramic cores for turbine blades of aero-engines and gas turbines. Its high fire resistance and low expansion coefficient can ensure the dimensional accuracy and stability of the core in high temperature environment.

V. Precision casting mold materials

Mullite powder can be used to manufacture precision casting molds, and its high refractoriness and low expansion coefficient can ensure the dimensional accuracy of molds at high temperature. In addition, the high purity and low impurity content of mullite powder can reduce the oxidation and pollution of castings.

VI. Casting coatings

Mullite powder can be used as the raw material of casting coating, which has good high temperature resistance, thermal shock stability and chemical erosion resistance. Castings with mullite powder coating have better smoothness and higher yield.

VII. Lightweight mullite castable

Lightweight mullite castable is a kind of material with mullite as the main component, which has excellent thermal insulation performance and low thermal conductivity. In industrial casting, this material can effectively reduce heat loss and improve energy utilization efficiency.

VIII. Substitution of high-cost materials

Mullite powder can replace zircon sand, corundum sand and other high-cost precision casting surface sand materials. Its low iron content, small expansion coefficient and high fire resistance can meet the requirements of complex precision castings.

IX. Summary of advantages

High fire resistance: the fire resistance temperature can reach 1750~2000℃.

Low expansion coefficient: reduce casting deformation.

High purity: reduce oxidation and pollution of castings.

Good chemical stability: no chemical reaction with molten metal.

Economy: Compared with zircon sand and other materials, the cost is lower.

Mullite powder is an ideal material for precision casting and high temperature casting because of its excellent properties, which can significantly improve the quality and production efficiency of castings in the casting process.