Extrusions

Question 1

Extrusions are Ideal for making metal _________ that can be a variety of shapes, solid, hollow, and with tight tolerances

Answer 1

profiles

Question 2

Extrusions requires relatively _______investment ($___-$___) and have a ______ time to market (_________)

Answer 2

cheap, 1-5, fast, 6 weeks

Question 3

About _______of metal extrusions are ___________(most of which are __________)

Answer 3

90%, aluminum, 6000 series

Question 4

The extrusion process is:
o Preheated __________ placed inside ____________
o Pressed by a ________ through the ___________
o __________ shape comes out the _________

Answer 4

Billet, ram, casting, extruded, die

Question 5

Billets are ______________ bars made by __________

Answer 5

cylindrical bars, casting

Question 6

Billet diameters can be as large as ___________ and must be _________ than the _________

Answer 6

350mm, larger, profile

Question 7

Profiles are typically ________ of the billet diameter and the Cross-sectional ratio between _______ and
________ is known as _____________, R

Answer 7

20-80%, billet, profile, extrusion ratio

Question 8

About ____________ of billet goes through the die in a single pass and the __________ can be recycled

Answer 8

80-90%, offcut

Question 9

A _______________________ is when a second billet is place behind another which can produce ___________ in extrusion

Answer 9

Billet-to-Billet Extrusion, weak spots

Question 10

To allow time to load subsequent billets, manufacturers aim for about _____________________

Answer 10

80% effective press time

Question 11

Sometimes billets are heated with a “__________________” where the die end is __________ than the ram
end which allows the material near the ram end and sides of the material to be heated to optimal temperature via __________ and _____________

Answer 11

temperature taper, hotter, friction, deformation

Question 12

The Flow of metal through die is similar to ______________from a larger channel to a
smaller one where metal funnels toward the ____________, with the largest deformations occurring in in
a _____________ region. Downstream of this region are wedge shaped “________________” where material does not pass through the die and is ______________

Answer 12

fluid, cone shaped, dead metal zones, scrapped

Question 13

The Extrusion diagram shows the ________________that material can be extruded vs. __________________
o Ignores _____________

Answer 13

Initial billet temp, temperature taper

Question 14

Line 1 of the Extrusion Diagram relates to the _________ where the _______ the billet, the ________ the ram will be able to extrude the billet

Answer 14

ram force, hotter, faster

Question 15

Line 2 of the Extrusion Diagram relates to the ___________of the material where as the velocity goes up, material will __________, causing _____________(aka ______________)

Answer 15

melting, heat up, hot cracking, hot shortness

Question 16

Line 3 of the Extrusion Diagram begins at the ______________ and increases with velocity again because material ___________ as velocity increases

Answer 16

cold cracking temperature, heats up

Question 17

The __________________ is the temperature below which the material will crack because it cannot ______________ to fit through die

Answer 17

cold cracking temperature, deform enough

Question 18

Overall, the Extrusion diagram shows the viable ______________ of initial billet temperature and exit velocity

Answer 18

combinations

Question 19

In general, extruders will want the velocity to be as __________ as possible

Answer 19

high

Question 20

Considering a Y- shaped profile:
The Die is a ________ made of ___________ and the material only makes contact with the die
over the ______________

Answer 20

flat disk, tool steel, bearing surfaces

Question 21

Determining bearing surface lengths is a highly case-specific process and is often done by ________________

Answer 21

Trial and Error

Question 22

Considering a Y- shaped profile:
You wish to distribute material evenly over profile but the material will want to flow ___________
near the center of the extrusion so the bearing surfaces are made ________
to increase the ________ and promote ___________ flow speed through the die

Answer 22

faster, thicker, friction, uniform

Question 23

When creating profiles with slots the ratio between the slot depth, H, to width, B, is _____________

Answer 23

Limited

Question 24

If H/B gets too _________, shear stresses in the die could be enough to break the ______________

Answer 24

high, tongue

Question 25

Hollows are created in solid billets using ________________ where metal separates and flows in around the ____________to rejoin around the ___________ and create a hollow shape

Answer 25

multipart dies, legs, mandrel

Question 26

There are several variations on hollows such as: “__________”, “___________”, and “_______________” (the most common)

Answer 26

Spider dies, bridge dies, porthole dies

Question 27

In hollow dies, rejoining the metal creates ______________ down length of extrusion

Answer 27

Weld seams

Question 28

6000 Series Extrusions are soft during extrusion which allows for ____________ and can be _______________ to gain strength

Answer 28

high exit speeds, Age Hardened

Question 29

What process is described here?
Alloy is solutionized near the melting point to distribute
the alloy material uniformly
2. Then the it is rapidly Quenched to room temperature
3. Then it is aged at temperatures around 165 C for
about 10 hours

Answer 29

Age Hardening

Question 30

In the cooling step of age hardening, the alloy elements (Mg and Si) form _____________ which restrict ___________ and thus increase strength

Answer 30

fine scale precipitates, dislocations

Question 31

In age hardening there is a significant trade-off where faster quench improves ______________in age but can also cause rapid ____________ and __________

Answer 31

Strength gain, deformation, warpage

Question 32

6000 series can be extruded in a large range or sizes, with profile weights of __________________ being a
practical range

Answer 32

.1kg/m - 20kg/m

Question 33

What series of Extrusion is described below?
High-strength alloys with magnesium, Zinc and
copper as the alloying elements
o Can be heat treated like 6000 series, but are stronger
o Often used for bikes and aircraft to save
weight
o Poor corrosion resistance
o Harder material so lower extrusion speeds and less
form freedom

Answer 33

7000 Series

Question 34

What other extrusion material is described here?
Sometimes extruded for tubing wiring, but difficult because of high temperatures involved

Answer 34

Copper

Question 35

What other extrusion material is described here?
Extruded for heat exchanger tubes and feedstock for forgings, but also requires High Temperatures

Answer 35

Brass

Question 36

What other extrusion material is described here?
Some niche applications, but very difficult

Answer 36

Carbon steel

Question 37

What other extrusion material is described here?
Few applications because hot shortness is a problem

Answer 37

Magnesium

Question 38

What extrusion method is described here?
o Uses a hollow ram with extrusion emerging through the center
o Used for hard materials materials and simple solid profiles

Answer 38

Indirect Extrusion

Question 39

What extrusion method is described here?
o Some fluid is placed between the ram and the billet
o Eliminates friction between billet and container
o So far it is an experimental method

Answer 39

Hydrostatic Extrusion