Manufacturing and Production Processes (Lecture #11)

These flashcards focus on key vocabulary and concepts related to the extrusion process discussed in Lecture #11 of the Manufacturing and Production Processes course.

Extrusion

A bulk deformation process where work metal is forced to flow through a die opening to produce a desired cross-sectional shape.

Direct Extrusion

Also known as forward extrusion, where the workpiece is pushed through a die opening while sliding along the container wall.

Indirect Extrusion

A process in which the die moves toward the billet and the billet does not slide relative to the container, except at the die.

Hydrostatic Extrusion

A type of extrusion where the container is filled with fluid to transmit pressure to the billet, reducing friction.

Impact Extrusion

A form of indirect extrusion suitable for producing hollow shapes through high-speed deformation.

Hot Extrusion

An extrusion process where the workpiece is heated above its recrystallization temperature to increase ductility.

Cold Extrusion

Typically used to produce discrete parts at room temperature, often resulting in greater dimensional accuracy.

Extrusion Ratio

Defined as the ratio of the cross-sectional area of the billet to the cross-sectional area of the product.

Frictions in Extrusion

Factors affecting metal flow in extrusion processes, which influence the energy required and the quality of the extruded product.

Dead Zone

A high shear area observed in extrusion where the material does not flow freely due to high friction.

Chevron Cracking

A defect that occurs in extruded materials due to hydrostatic stress leading to internal cracking during the extrusion process.

Surface Cracking

Cracking of the surface material resulting from high temperature, speed, and friction during the extrusion process.

Die Angle

The angle of the die which influences the material flow, friction, and forces required during the extrusion process.

Billet

The initial piece of metal that is used as material for the extrusion process before being shaped.

Butt

The portion of the billet that cannot be forced through the die opening and must be removed after extrusion.

Ram Pressure

The pressure exerted by the ram to push the billet through the die in the extrusion process.

Turbulence in Metal Flow

A condition in which metal flow becomes irregular due to high speeds or poor lubrication, affecting the quality of the extruded product.