Why Do Precision Castings Produce Pores?

There are three common reasons that precision castings can produce pores as follows.
1. Alloy liquid contains too much gas and precipitates during solidification. When the gas in the cavity, the gas volatilized by the paint, and the gas which is solidified and precipitated by the alloy, the pores formed in the precision casting are left when the mold is poorly exhausted. 2. During the filling and solidification of the molten metal, holes are formed on the surface or inside of the casting due to gas intrusion. 3. The gas volatilized by the paint invades.