Flow Porosity

• Air entrapment due to flow problems
• Cause surface or internal defects

Gas Porosity

• Entrapped gases caused by air, lubricants and separating agents
• Aluminum in the liquid phase has a high solubility of hydrogen, when freezing the dissolved hydrogen creates bubbles

Process Optimizing to reduce Porosity

• Reduce spraying to the necessary minimum
• Temperature regulation must be precise along the metal flow line to avoid early freezing
• Use ring piston system
• Precise Dosing
• Reduce the hydrogen content in the melt to a minimum – furnace in-line degassing
• Lower speed at the gate