Effects of Extrusion Process Conditions on "Die Pick-Up"

In this research AA6060 alloy was used and was
extruded at 25m/min, 30m/min, 35m/min, 40m/min and
45m/min for a particular profile. The highest exit
temperature increased from 542°C to 567°C when the
extrusion speed was increased from 25m/min to 45m/min.
Three types of die pick-up were identified. They were
named as normal pick-up, die line pick-up and lump
pick-up. Normal pick-up occurred regardless of the
extrusion speed and exit temperature; however the
amount of normal pick-up did not increase when the
extrusion speed was increased. Die line pick-up
occurred when the extrusion speed was 45m/min and
appeared only on the die lines. Lump pick-up is not
significant since it was very rare.
AA6060 (0.4%Mg and 0.5%Si) alloy has about 0.27%
excess silicon and therefore at 555°C, Mg2Si
particles react with aluminium and excess silicon to
form liquid. However normal pick-up and die line
pick-up still occurred at temperatures lower and
higher than 555°C and therefore it confirms that
eutectic reactions do not influence formation of pickup.
Therefore die pick-up is most likely to be caused
due to a mechanical process rather
than a metallurgical process.

Autorentext

Robbie Peris was brought up in Sri Lanka and migrated to
New Zealand in 2002. He obtained his BE(Hons) and ME(Hons) from
AUT University Auckland New Zealand. He did his Masters Thesis
with Fletcher Aluminium. Currently Robbie Peris is working as a
Research Officer at AUT University and is part of the metal
forming group.

Klappentext

In this research AA6060 alloy was used and was
extruded at 25m/min, 30m/min, 35m/min, 40m/min and
45m/min for a particular profile. The highest exit
temperature increased from 542°C to 567°C when the
extrusion speed was increased from 25m/min to 45m/min.
Three types of die pick-up were identified. They were
named as normal pick-up, die line pick-up and lump
pick-up. Normal pick-up occurred regardless of the
extrusion speed and exit temperature; however the
amount of normal pick-up did not increase when the
extrusion speed was increased. Die line pick-up
occurred when the extrusion speed was 45m/min and
appeared only on the die lines. Lump pick-up is not
significant since it was very rare.
AA6060 (0.4%Mg and 0.5%Si) alloy has about 0.27%
excess silicon and therefore at 555°C, Mg2Si
particles react with aluminium and excess silicon to
form liquid. However normal pick-up and die line
pick-up still occurred at temperatures lower and
higher than 555°C and therefore it confirms that
eutectic reactions do not influence formation of pickup.
Therefore die pick-up is most likely to be caused
due to a mechanical process rather
than a metallurgical process.