Virtual Labs

Q1. Which specific phenomenon occurs if the extrusion speed is too high, leading to surface cracking of the profile?

a: Elastic recovery Explanation

Explanation

b: Hot shortness (Speed cracking) Explanation

Explanation

c: Cold shut Explanation

Explanation

d: Die gaping Explanation

Explanation

Q2. In upsetting theory, what is the maximum length of unsupported bar stock that can be upset in one blow without risk of buckling?

a: One time the diameter of the bar Explanation

Explanation

b: Three times the diameter of the bar Explanation

Explanation

c: Five times the diameter of the bar Explanation

Explanation

d: Ten times the diameter of the bar Explanation

Explanation

Q3. Why is 'Indirect Extrusion' theoretically more energy-efficient than 'Direct Extrusion'?

a: Because it uses water-based lubricants instead of oil Explanation

Explanation

b: Because there is no relative motion between the billet and the container wall Explanation

Explanation

c: Because it allows the use of smaller flywheels Explanation

Explanation

d: Because it operates at room temperature Explanation

Explanation

Q4. What is the primary function of a 'Dummy Block' in the extrusion process?

a: To pre-heat the die before the billet arrives Explanation

Explanation

b: To protect the main ram from high heat and pressure while allowing air to escape Explanation

Explanation

c: To shear the discard from the finished profile Explanation

Explanation

d: To measure the temperature of the container Explanation

Explanation

Q5. How does 'Dead Metal Zone' formation affect the final product in extrusion?

a: It improves the surface finish by acting as a filter Explanation

Explanation

b: It causes the center of the billet to flow faster than the edges, potentially trapping surface oxides Explanation

Explanation

c: It reduces the total tonnage required by the press Explanation

Explanation

d: It eliminates the need for a shear discard Explanation

Explanation

Upsetting and Extrusion Presses