Shrinkage Cavity & Porosity (glossary)
缩孔与缩松（术语）
标签：缩孔, 缩松, 凝固, 补缩, 热节
缩孔是铸件最后凝固的热节部位因液态收缩和凝固收缩得不到补缩形成的集中孔洞；缩松则是分散的微小孔隙。两者均由顺序凝固失控造成，通过增设冒口、冷铁和合理浇注温度控制。区别于气孔——气孔源于气体，内壁光滑圆整。
A shrinkage cavity is a localized void at the last-to-solidify hot spot caused by unsatisfied liquid and solidification shrinkage; porosity is dispersed micro-voids. Both result from loss of directional solidification control and are managed with risers, chills and proper pour temperature. Unlike gas porosity, shrinkage has rough, angular walls. ---