What common internal and surface defects occur on copper castings and control solutions?

Improper melting parameter setting,unreasonable mould structure and unregulated cooling steps will trigger various defects that weaken the service life of copper castings.Porosity bubbles are caused by dissolved oxygen and hydrogen inside molten copper;strict deoxidation operation and fully dried mould preheating can cut bubble generation.Shrinkage cavities mostly appear at thick wall intersections due to uneven solidification,solved by adding feeding risers in mould design to supplement liquid alloy during cooling.Cold shut lines form when separated copper liquid flows fail to fully fuse,improved by moderately raising melting temperature and optimizing runner layout.Oxide inclusion defects come from incomplete slag removal in melting furnaces,requiring standardized skimming procedures before pouring.Thermal cracks are induced by excessive internal stress from rapid cooling,balanced by graded mould preheating and slow cooling after filling.X-ray and penetration inspection can screen unqualified copper castings before subsequent processing.