09-22/2025
In sand casting, shrinkage cavities and shrinkage porosity are the most common internal defects in castings. Shrinkage cavities typically manifest as irregular large cavities in thick areas or heat center zones of the casting, characterized by rough walls and dendritic crystals. Shrinkage porosity appears as fine dispersed pore clusters, predominantly occurring along casting axes or at thickness junctions. These defects severely compromise mechanical properties and airtightness, potentially leading to cracks and premature failure. As core processes in the casting workflow, mold design and core-making operations play a decisive role in preventing shrinkage porosity and cavities. This article systematically outlines effective measures to reduce their occurrence rates by focusing on critical aspects of mold-making procedures.
