Tony Withers: Lab: Multi-anvil

Multi-Anvil: Standard Operating Procedure

Note that web-based summaries of standard operating procedures are not exhaustive.
Not all of the relevant safety information is included in this document.
Further training is required for safe operation and will be provided in person.

This file contains instructions for how to set up a multi-anvil experiment.

To start an experiment

  1. [Skip this step if the power is already on] Turn on the power to pressure and temperature controls by pulling on the power switches.

  2. Turn HEAT off.

  3. Start Igor Pro and initialize the data logger (Logger > Initialise Data Logger). If the logger fails to initialise, close Igor and try disconnecting and reconnecting the USB-serial converter before starting Igor again.

  4. If the pressure controller is not fully retracted (decrease pressure limit isn’t illuminated), reverse the motor to prime the controller.

  5. Remove wedges and examine thin plastic on wedges and thicker plastic lining of the containment ring for damage. Replace if necessary. When replacing lining there must be no overlap (put the new piece in, mark it with a sharpie, take it out and cut off any excess with a scalpel). Wipe the inside of the hatbox (inner surface of steel containment ring) with a cloth moistened with T-9, to stop it rusting. Thin plastic must be glued to the wedges with thinnest possible layer of loctite 495.

  6. Vacuum dust from hatbox. DO NOT use compressed air to blow dust around – it’ll get everywhere.

  7. Clean surfaces using solvent (ethanol, methanol, whatever). Lubricate inner surface of plastic lining containment ring and outer surfaces of wedges with PTFE aerosol. Insert bottom wedges and G10 spacers.

  8. Lubricate the assembled cube with PTFE.

  9. Nest the assembled cube between the wedges. Insert type K wires beneath G10 to make contact with an anvil. Attach thermocouple wires:

    Type D
    (+) : W97Re3, white insulation – compensated alloy 203
    (-) : W75Re25, red insulation – compensated alloy 225

    Type K
    (+) : yellow insulation – Chromel
    (-) : red insulation – Alumel

    Ensure that there is no possibility of any wires shorting top and bottom wedges.

  10. Place the top wedges over the cube and drop the G10 spacers into the spaces between the wedges. Rest the top plate over the center of the wedges, and carefully roll the Walker module over the hydraulic cylinder. Always make sure that the module rolls very slowly on the rails.

  11. Mate thermocouple connectors and check for sensible temperature reading.

  12. Set up the data logger. Logger > Reset Data Logger. Type in an experiment name and number. Click green start button and make sure pressure is being monitored.

  13. Set up the pressure-temperature program.

  14. Open the compressed air valve. Open the path between the pressure controller, pump and multi anvil (turn valves gently!). Press the 'close' button to start the hydraulic pump and reduce the daylight. As the ram closes, close down the pump valve so that the pressure does not rise too quickly. As the top plate makes contact with the overlying platen, the pump valve should be nearly closed. Watch the pressure reading on the computer screen and adjust the valve to increase pressure at about 1 psi per second. Continue to pressurize to ~200 psi. At >200 psi, slowly close the pump valve and turn off the pump. Close the compressed air valve.

  15. In data logger window select Logger > Motor Control and manually increase the pressure controller motor speed (this can be done before turning off the pump in the previous step if you want to make a smooth transition between pressurizing systems). If the pressure-failure alarm trips due to fluctuations in the pressure reading, you will have to increase speed from zero again. Pressure controller and multi anvil valves should be open a little. If line pressure drops much below 200 psi, the pressure-failure alarm will trip continuously.

  16. Start recording data (you can shift-click to start all channels simultaneously). Start the pressure-temperature program cycle.

  17. Check that cooling water hose is connected, the water valves open. and the chiller on.

  18. Check that OP is zero, hit the START/RESET button and turn HEAT on.

  19. Make sure the experiment record sheet is filed in the ring binder, and that you’ve filled in your name, a description of the experiment and the target conditions.

Check List

To end an experiment

  1. When pressure is reduced and pressure controller is fully retracted (decrease limit active) the motor should turn off and the data logger should stop and display a summary of the experiment.

  2. Open the pump and multi anvil valves. Open compressed air valve and press the 'open' buttion to start the hydraulic pump. Run pump until the ram has retracted enough that the wheels rest on the tracks. Turn off the pump and close the compressed air valve.

  3. Disconnect thermocouple connectors.

  4. Open the hatbox and remove the cube, trying to prevent ceramic debris falling between the wedges. Vacuum dust from the wedges.

  5. Examine anvils for damage and record their condition (wear eye protection). Place anvils under cover in case any shards of carbide are ejected. Clean the anvils for the next user.

  6. Print experiment log and insert it in the ring binder next to the record sheet. If anything funky happened during the experiment, print a record and place that in the binder, too.

Problems

If case you run in to any problems, call Tony: office number is: 4-3336, else hit the 'audrey' button on the phone to call Tony at home.

 

ACW 2007; updated 2012.

 

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