No casting is perfect, and no foundry is either — but great foundries control defects at the process level rather than discovering them at inspection. Understanding the four classic aluminum casting defects helps you ask better questions and judge supplier quality.
Each defect has a signature cause: gas porosity comes from dissolved hydrogen, shrinkage from poor feeding, cold shuts from wrong pouring temperature, and inclusions from dirty melt or dross.
Key Points
- Gas porosity: rounded voids, often near the surface. Prevention: degassing with GBF (we run two degasers), dry ladles and controlled pouring.
- Shrinkage: jagged internal voids in heavy sections. Prevention: correct gating/riser design, mold-flow simulation and directional solidification.
- Cold shut: a visible seam where two flows met without fusing. Prevention: correct pouring temperature and gating design.
- How we prove it: X-ray digital imaging on safety parts, metallographic analysis on request, and density checks — with records you can audit.