Defects occurring within the process window
As mentioned above, operating the extrusion process outside the process window
leads to various product defects. However, a number of defects can still arise when
the extrusion is operated within the process window. Die lines and surface pickups
are, among them, the most severe and relevant to the AA 6XXX series alloys. They
can virtually appear throughout the process window.
Extrudate temperature
Extrusion speed
Hot cracking
Incipient
melting
Undissolved
Mg2Si
Insufficient
pressure
A
C B
Process
window