Manufacturing and Production

Casting Defects, Solidification and Yield Improvement

Most foundries carry a scrap rate they have stopped questioning, and most of that scrap comes from a handful of defects that repeat because the diagnosis stopped at the symptom. This course goes to the cause. Delegates work through solidification: nucleation, growth, the temperature gradient and the feeding path that determines where the last liquid freezes. Shrinkage is treated as the defect it is, distinguishing macro shrinkage, centreline porosity and micro porosity, each pointing to a different failure in feeding. Gas defects are covered, including hydrogen pickup, blowholes and pinholes, and the moisture and cleanliness that produce them. Inclusions, slag and sand entrainment follow. Cracks are addressed, separating hot tears from cold cracks by their appearance. Mould and metallurgical defects are covered. Diagnosis method is taught explicitly: reading the location, shape and surface of a defect before proposing a cause. Yield improvement follows through riser and gating optimisation. The course closes on scrap tracking and on proving a fix.