What causes the powder layer to fall off inside the precision casting mold shell?

The reasons why the powder layer falls off in the precision casting mold shell are as follows:

Mold material problem: The material does not have sufficient hardness and toughness. After a period of use, the inner wall surface of the mold will wear out, resulting in peeling and falling off.

Problems with mold usage temperature: Concentrated heat or a temperature that exceeds the tolerance of the mold material will cause large thermal expansion and contraction inside the mold, and cracks may occur after long-term use.

Mold humidity problem: If the mold is left in a humid environment for a long time, the inner wall of the mold will be corroded, causing it to lose its original hardness and toughness and become brittle and brittle.

Mold making problems: There are debris, bubbles and other defects on the inner wall of the mold.