1. Gas Porosity
Description
Spherical voids with smooth inner walls caused by entrapped air/gas under high pressure.
Root Causes
    Turbulent filling traps mold cavity air
    Oil/gas from plunger lubricants or release agents
    Evaporated residual water from low mold temps
Solutions
✔ Optimize gating/venting design (X-velocity <40m/s)
✔ Switch to water-based release agents (<0.5% oil content)
✔ Ensure complete air blow-off before shots
✔ Implement vacuum-assisted casting (≤50mbar)
2. Edge Shrinkage
Description
Depressions at corners/R-sections due to localized solidification shrinkage.
Root Causes
    Hot spots from inadequate cooling in sharp features
    Insufficient molten metal feed during late-stage solidification
Solutions
✔ Add conformal cooling channels (<3mm from surface)
✔ Modify corner radii (R>2.5× wall thickness)
✔ Increase intensification pressure (≥800bar for Al)
3. Core Pin Shrinkage
Description
Surface sinks near ejector/core pin tips.
Root Causes
    Delayed solidification at high-temp core areas
    Restricted metal feed to isolated sections
Solutions
✔ Use beryllium-copper core pins (thermal conductivity >200W/mK)
✔ Implement pulsed cooling on cores (5-10s cycles)
✔ Reduce core L/D ratio to ≤4:1
4. Macro Shrinkage
Description
Large irregular voids in thick sections with dendritic inner surfaces.
Root Causes
    Premature gate freezing cuts off metal feed
    Lack of directional solidification

Solutions
✔ Apply squeeze pins to critical sections
✔ Implement thermal management (ΔT <30°C across mold)
✔ Modify wall transitions (taper angle >15°)
5. Microporosity
Description
Spongy clusters of micro-voids in thick sections.
Root Causes