a)If we are considering the volume of material before and after
extrusion is same.
Volume of billet is given as area of billet × length
π/4(0.1022)×1.83=0.0149m3
Extrusion ratio of aluminium 'R' is~ 400:1
The area of extrusion = Area of billet /R
= 8.17×10-3m2 / 400
=2.04×10-5m2
Volume of extrusion = volume of billet
Area of extrusion × length= 0.0149m3
Length of extrusion = 0.0149/area of extrusion
=0.0149/(2.04×10-5)=730.4m
But around 10% to 15% is lost as butt thickness
Taking 10%of extrusion length
Therefore actual length =730.4-73.04= 657.4m
b) the exiting velocity is 60m/min
time taken for extrusion of 6feet (1.83m)long billet in
minutes
=657.4m/ 60= 10.95 minutes.
