Factors Affecting Precision Casting

2022-03-19

In general, the dimensional accuracy of precision castings is affected by many factors such as casting structure, casting material, mold making, shell making, roasting, pouring, etc. Any one of the link settings and unreasonable operation will change the shrinkage rate of the casting. Lead to the deviation of casting dimensional accuracy and requirements. The following are factors that can cause dimensional accuracy defects in precision castings:

(1) The influence of the structure of the casting: a. The wall thickness of the casting has a large shrinkage rate, and the casting wall is thin and the shrinkage rate is small. b. The free shrinkage rate is large, and the hindered shrinkage rate is small.

(2) Influence of shell-making materials: The use of zircon sand, zircon powder, Shangdian sand, and Shangdian powder has a small expansion coefficient of only 4.6×10-6/℃, so it can be ignored.

(3) Influence of shell roasting: Due to the small expansion coefficient of the shell, when the shell temperature is 1150 °C, it is only 0.053%, so it can also be ignored.

(4) Effect of casting temperature: The higher the casting temperature, the greater the shrinkage rate, the lower the casting temperature, the smaller the shrinkage rate, so the casting temperature should be appropriate.

Precision Casting

Previous: Precision casting has broad prospects for development

Next: Industrial Reform of Precision Casting