What Are Common Defects of Aluminum Castings and How to Reduce Them?

Improper melting,mold design or cooling control will trigger typical defects in aluminum castings that weaken service performance.Gas porosity,the most frequent issue,arises from dissolved hydrogen in molten metal trapped during solidification;strict melt degassing and dry mold preheating can lower void probability sharply.Shrinkage cavities form in thick wall sections due to uneven solidification,solved by adding reasonable riser feeding structures in mold design.Cold shut lines appear from insufficient fluid fusion of separated aluminum liquid flows,improved by optimizing gating channel layout and raising melt temperature moderately.Oxide inclusion defects stem from poor flux cleaning during melting,which requires standardized slag removal procedures before pouring.Cracks occur under excessive thermal stress from rapid uneven cooling,balanced by graded mold preheating and slow cooling post-filling.Strict whole-process inspection via X-ray,penetration testing and dimensional checking can screen defective castings before delivery to avoid assembly failure.