There are two main types of shrinkage in sand casting: solidification shrinkage and pattern maker’s shrinkage.
Shrinkage - Solidification and Cooling.
Process improvements in sand casting over the past 60 years (part 1) - Haworth Castings
Brief introduction of shrinkage cavity and porosity in semi solid die casting – ZHY Casting
Shrinkage porosity and shrinkage cavity casting defects and their control methods – ZHY Casting
19M024 Internship Report, PDF, Casting (Metalworking)
Microstructures of the sand-cast alloy: (a) porosity and (b) eutectic
5 Types of Casting Defects and How to Prevent Them in Your Products
Shrinkage - Solidification and Cooling.
question about aluminum shrinkage Home Model Engine Machinist Forum
The Key Stages in Sand Casting - Haworth Castings
Simulation of Shrinkage Porosity Formation During Alloy Solidification