The material selection of sprue cup is very important for its performance and service life. The following are several common sprue cup materials and their characteristics:

I. Ceramic materials

Ceramic material is one of the most commonly used materials for sprue cups, which has the following advantages:

High fire resistance: able to withstand temperatures as high as 1600℃ or even higher.

Good erosion resistance: smooth surface, small flow resistance of molten metal, not easy to be eroded by molten metal.

Strong slag corrosion resistance: good chemical stability, not easy to react with molten metal, reducing slag inclusion.

Excellent thermal shock performance: it can resist sudden temperature change and reduce thermal cracking.

Common ceramic materials include silicon-aluminum materials, alumina, aluminum nitride composite ceramics and so on.

II. High alumina clay materials

The refractoriness of high alumina clay can reach 1700℃~1750℃, and it has good high temperature stability and thermal shock resistance. The sprue cup made of this material has high strength, erosion resistance and good thermoplasticity, and can buffer thermal stress.

III. Paper composite materials

Paper composite sprue cup is a new type of material, which has the following characteristics:

Energy saving and environmental protection: it can replace the traditional ceramic sprue cup and reduce the resource consumption of refractory materials.

Good high-temperature performance: it can meet the requirements of high-temperature strength and refractoriness of sand casting products.

Improve casting quality: ensure the cleanliness of casting melt and reduce inclusions.

IV. Composite materials

Some sprue cups use composite materials, such as aluminum nitride and silicon nitride composite ceramics. This material is not only resistant to high temperature, but also has low thermal expansion coefficient, non-adhesion to aluminum, high strength and long service life.

V. Refractory brick materials

Refractory brick materials (such as mullite, corundum brick, etc.) are also commonly used in sprue cups, which have high fire resistance and can withstand extremely high temperature environment.

VI. Metal materials

In some special cases, the sprue cup will also be made of metal materials (such as cast iron). Metal materials have the advantages of good thermal conductivity and wear resistance, but they are usually not as resistant to high temperature as ceramic materials.

VII. Summary

When selecting the material of the sprue cup, it should be considered comprehensively according to the specific casting process, the type of molten metal, the temperature requirement and the cost. Ceramic materials and high alumina clay materials are the most widely used materials at present, while new paper composite materials provide a new choice for environmental protection and energy saving.