Operations Manual
Equal Channel Angular Pressing
Introduction:
Hello and thank you for your recent
purchase of an Equal Channel Angular Press (ECAP).
The ECAP is a fabricated die with a 45-degree angle
change that makes a sample of material under go
shear deformation. This shear deformation takes
this sample of material and causes severe plastic
deformation in the sample. Unlike other systems
the ECAP that you have purchased is designed to
deform samples of copper while submerged in liquid
nitrogen. This is done because of the Hall-Petch
Phenomenon, which says the colder the temperature
at which the sample is deformed the smaller the
grain sizes will be. Making the material increase
in strength.
Figure 1: View of all the parts required:
In figure 1, above you will see all the parts you
should have in order to assemble the ECAP. To setup
the ECAP please refer to the assembly section. Figure
2 on the next page will show you what the solid
view of the parts look like.
Figure 2: Solid view of all
parts required
In order to operate the die we will be using a 500-ton
press shown in figure 3, with at least a 20-inch
height workspace. Please refer to assembly to see
how to setup the die and press.
Figure 3: 500-ton press
When the sample of material (copper) is done with
a pass through the die it will need to be resized.
This is going to be done with a separate machine
called a resizing die. The resizing die will return
the sample back to its original size so that it
can be ready for another pass. The sample must be
marked so you can remember the orientation of the
sample after each pass. The sample will need to
be rotated 90 degrees after every pass. So be sure
to mark the sample so the orientation of the sample
can be remembered. The samples will under go at
8 passes through the die. This depends on the type
of material being used. This was determined from
room temperature dies that found the materials did
not benefit from more than 8 passes through the
die.
Remember these instructions are for
a sample of copper.
Equal
Channel Angular Processing
Safety Equipment/Tools Needed:
Eyes:
• Chemical safety goggles and face shield
are recommended when handling N2 liquid.
Skin:
• Wear loose fitting thermal insulated leather
protective gloves.
• Wear long sleeve shirt for handling liquid.
• Wear safety shoes if handling cylinders.
Respiratory:
• Use a self-contained breathing apparatus
or positive pressure airline with mask in oxygen-deficient
atmospheres.
• Respirators will not function.
Special Precautions:
• Ventilation:
1. Use local exhaust and
2. Mechanical ventilation.
• Storage:
1. Store and use with adequate ventilation.
2. Containers should be stored upright and firmly
secured to prevent falling or being knocked over.
3. Protect containers from physical damage; do not
drag, roll, slide, or drop.
4. Use a suitable hand truck for container movement.
5. Liquid containers will vent nitrogen if internal
pressure builds up, so these containers should be
stored in well-ventilated areas.
Other Tools Needed:
•
Standard Crowbar or Large Flat-headed screwdriver.
• Protection shield to place in front of 500-ton
press during experimentation.
• Tongs (minimum of 18 inches) capable of
retrieving processed sample from reservoir.
• Wrench (11/4in.)
• Re-sizing Die.
Total Assembly/Component
List
1:) Top Bolster Plate
2:) Piston Cylinder
3:) Right Die Half
4:) Left Die Half
5:) 3/4in x 9in. Bolt (11 total)
6:) 11/4 in. Nut (11 total)
7:) Insulated Bath
8:) Extrusion Channel
9:) Catch pan
10:) 2-inch Bottom Bolster plate (not shown)
Assembly
of the apparatus:
In order to insure that the die and press
work in unison together, below is an ordered list
of assembly instructions for the operator of the
die. It also gives proper instructions of the placement
in the press.
Note: the part in the numbered diagram will be
denoted by a “(#)”
Die Halves Connection:
1.
Find a flat level table to begin assembly (check
with level).
2. Remove the left die half (4) from the shipping
box/storage
3. Remove the right die half (3) from the shipping
box/storage
4. Place the right die half (3) and the left die
half (4) parallel to each other as shown in figure
1.
5. After aligning the two dies, press them together
to make a solid block as seen in figure #. Make
sure the holes and channel are aligned on both halves
to insure proper sealing.
6. Insert the eleven 9” bolts (5) into the
boltholes of the left die and extending through
the right die. Completely insert all bolts (5) before
nuts are screwed on.
7. Once all bolts are completely inserted, screw
the nuts (6) on one by one, holding the head of
the bolt still with a wrench (Do not tighten bolts
and screws until all are snug against the die).
8. Slowly tighten each bolt ¼ turn each until
the two die become snug together. When finished
it should look like figure 4.
Figure 4: Assembled
die halves
Die
Placement in Bath & Press Placement
1. After die is fully assembled, place the bath
on the bottom bolster plate, with the catch pan
facing front and hanging off the edge and then,
place the die in the bath (7). Be sure to align
the bottom of the die with the 1” alignment
plates coming up from the bath floor see in figure
#.
2. Once the die is in place in the bath, and on
top of the bottom bolster plate, the bath and bolster
plate are ready to be set up on the press.
3. Make sure the press is separated in the vertical
direction to its maximum (20”).
4. Attach the bottom bolster plate (10), with the
bath and die on top, to the bottom of the press
(secure bolts down)
5. Attach and secure the top bolster plate (1) to
the top of the press. Four bolts will be used for
this process.
6. Pour the liquid nitrogen into the bath and allow
the dies to reach the equilibrium temperature.
7. Slide the square end of the piston cylinder (2),
in the slot in the top bolster plate.
8. Be sure that the bath is stable and aligned and
that the piston (2) is aligned with the extrusion
channel (8).
Sample Size
The samples that the dies are able to accommodate
are .75 inch outside diameter, and 6 inches long.
The die was designed for use with copper samples,
the use of a sample of a different material may
cause damage to the die and personal injury.
Setup
The following sections illustrate how to properly
setup the die assemblies and press to process a
sample.
500 Ton Press Orientation
The first step to setup up the assembly begins
with properly setting up the press. First, the press
must be visually inspected for any visible defects.
Next, making sure the press is properly lubed; set
it to the fully open position.
Bolster Plates
The 2-inch aluminum, bottom bolster plate (10)
must be set on a table or cart for the bath and
die to be placed on top. The 1-inch top bolster
plate (1) must be bolted to the top of the press
opening with the notch for the piston on the top.
Bath Placement
The liquid nitrogen bath container (7) can next
be placed on the bottom bolster plate and oriented
so that the catch pan (9) faces the front and is
hanging over the edge of the bottom bolster plate.
Die Insertion
Take the left (4) and right (3) side die halves,
and place them together. Insert the bolts (5) through
both dies and place the nuts (6) on the end. The
bolts should be tightened finger tight, and then
another ¼ turn afterwards (refer to section
“Die Halves Connection” for more detailed
instruction). Then, place the dies into the bottom
bolster plate and transfer over to the press. This
assembly will be heavy, so a rolling cart should
be used to move it closer to the press (refer to
section “Die Placement in Bath & Press
Placement“ for more detailed instruction).
Adding Liquid Nitrogen
Wearing safety goggles and gloves for protection,
carefully poor the liquid nitrogen into the bath
till it is almost full up to the top. Next, place
the lid on top and be sure to wait a sufficient
amount of time to allow the die to reach an equilibrium
temperature. The bath will need to be refilled periodically
as the liquid nitrogen boils off.
Sample Placement
Before the samples are to be pressed, they must
be cooled in a liquid nitrogen tank. Remove the
lid and place a sample from the liquid nitrogen
tank into the hole in the top of the die. Then,
put the lid back in its place.
Piston Arrangement
Now, the piston (2) can be inserted into the top
bolster plate. With the square base on the topside,
slide it into the notch in the bolster plate and
line it up with the hole in the lid and die.
Experimental Procedure
1. The first thing to do is to follow the setup
instructions to assemble the ECAP and the press.
Remember to mark the sample to be able to remember
its orientation
2. Place the sample of copper, with a diameter of
0.75inches and length of 5 inches, into the die
channel. The lid might be off when placing the sample
into the die channel See figure 5 on next page.
Caution use gloves our tongs to place sample in
channel and then replace lid if not on. Allow sample
to come to equilibrium temperature; should take
about 1hr.
Figure 5: Showing sample
going into the die
3. If piston cylinder is not aligned then please
align them now.
4. Once the piston cylinder is aligned with channel
you are ready to begin pressing the sample. To ensure
that the sample is not pressed to fast the minimum
press time should be 2 minutes.
NOTE: When performing the ECAP there should
be two samples pressed one after the other. The
first sample will be pressed out but the second
will remain in the die. It will be help full to
have one extra sample to be used to push the last
sample out with out using one of the samples that
have already been through the die 8 passes.
5. Once the sample has been pressed through remove
lid and use tongs to reach in to the catch pan and
grab sample and remove it out of the liquid nitrogen.
6. The samples should still be marked and able to
tell how it was oriented before, so after resizing
it can be reoriented by 90 degrees.
7. The sample will go into the resizing die to have
the diameter of the sample corrected back to 0.75
inches.
8. After resizing the sample will be placed back
into the die channel. But remember the sample must
be rotated by 90 degrees from its previous position
(until it has gone 360 degrees). The sample must
pass through the die in sets of four so that the
sample is deformed evenly getting all 360 degrees.
So by sending the sample through 8 passes the whole
sample will have made two complete revolutions.
9. Steps 5-8 should be repeated to the desired number
of passes (8)
10. There will be one sample left in the die that
you care about. So place the third extra sample
in die channel and press out the second sample that
you care about leaving the extra sample that does
not matter in the die.
11. Follow disassembly to take apart die and remove
last sample.
Disassembly of the
Die
This is a brief explanation of the complete disassembly,
also noting the trouble-shooting for jamming of
the copper sample in the extrusion channel.
1. Allow ample time for the liquid nitrogen to
evaporate and for the assembly to reach room temperature.
2. Remove piston (2) from the top bolster plate
(1) notch.
3. Remove the Styrofoam lid from the insulated bath.
4. Carefully remove the bath and die assembly along
with the bottom bolster plate (10) from the press.
5. Remove the die assembly from the insulated bath
and place on a level table.
6. Loosen and remove the 9” bolts (5) and
nuts (6) from the die assembly.
7. Insert screwdriver/crowbar in the V-notch between
the two die halves and pry them apart.
8. After this point the copper sample left in the
die is then removed from the extrusion channel.
Note: This process will be used for the case of
a sample getting jammed in the extrusion channel
also before another pass.
