Extrusion of AL alloys and Die design?

Question

Help please:

1) Explain why during hot extrusion of aluminium alloys pressure, extrusion speed needs to be controlled.

2) Explain what the most important die design feature is so as to maximise forced feeding and hence to minimise shrinkage porosity in squeeze casting.

Thank u so much!

Answer 1

http://www.diva-portal.org/ntnu/abstract...

http://en.wikipedia.org/wiki/Extrusion

http://student.dcu.ie/~lipowim2/files/DC...

http://www.google.com/search?sourceid=na...