Question

Using direct extrusion process, a round billet of 100 mm length and 50 mm diameter is extruded Considering an ideal deformation process (no friction and no redundant work) extrusion ratio 4 and average flow stress of material 300 MPa, the pressure (MPa) on the ram will be

• A. 416
• B. 624
• C. 700
• D. 832

Answer 1

The correct option is A 416

$L_0=100,{\sigma }_y=300MPa$

$d_0=50mm$

$\text{Extrusion ratio}=\frac{A_0}{A_1}=4\text{and}{A}_0=1962.5m{m}^2$

$A_1=\frac{A_0}{4}=\frac{\frac{\pi }{4}\times {50}^2}{4}=490m{m}^2$

$\text{Extrusion pressure}=300ln\text{(extrusion ratio)}$

$=415.8MPa$