what is shrinkage factor for investment casting of steel wha

what is shrinkage factor? for investment casting of steel what is the shrinkage factor generally used?

Solution

1. Shrinkage Factor= Before we define shrinkage factor, we first have to understand shrinkage allowance.

A shrinkage allowance for metal or steel casting is something that must be figured into a design from the very beginning. As the molten metal or steel cools and solidifies it will begin to contract. This means that although the molten metal completely filled up a mold but by the time the casting becomes cold and solidified, the casting is smaller than the mold.

This means that a pattern must be made larger than the size of the casting required. For this designing of the pattern, a term \"shrinkage factor\" is used where-

Shrinkage factor= size or dimensions of the pattern/ size of reqired casting

Thus the shrinkage factor is always greater than 1

2. Shrinkage factor generally used for investment casting of steel-

The investment casting process is a metal casting process where a disposable wax replica, or “pattern”, which is identical to the casting desired, is produced from an injection molding type of tool. The wax models are engineered to be slightly larger than the casting due to the volumetric shrinkage of metal when it cools from a liquid to a solid.

The shrinkage factor generally used for the investment casting of steel varies from 1.05 to 1.10