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| Laura Lambert wrote: |
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Thursday, November 05, 2015, 16:19
Springs coated with TaC and loaded into container for sintering.
3x Ta heat shield.
EVAP2 currently pumping down.
Friday, November 06, 2015, 08:39
Opened HS water valves, no leaks detected.
Tapped up manually to 35A.
IGP1 = 5.5e-7 Torr.
Friday, November 06, 2015, 10:08
IGP1 = 5.8e-7 Torr.
Vacuum stable.
Initiating auto-ramp at 0.2A/min and 0.1A/min with final setpoints of 450A and 230A for the TGHT and TBHT respectively.
See photos attached to view how springs were coated and loaded into container.
Monday, November 09, 2015, 09:07
TGHT reached 450A, 7.2V ~8pm sat, nov 7th.
OMEGA = 1775C
IGP1 = 3.2e-7 Torr.
Tapping up manually to 1900C.
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Monday, November 09, 2015, 12:30
Checked the temp on the inner surface (not at the spring) of the container was around 2050C at 500A.
The TaC coated spring is reading at 1900C; that's what the OMEGA is reading with the setting for 2-colors and slope at 0.98.
Lower TGHT to 450A/ 7.12V.
By comparing the data from the previous temp curve (OMEGA slope at 0.98) with no material inside the container, the voltage and current plot is aligned with the curve.
Changed OMEGA setting slope to 1.04. Current temp is reading at 1917C at 450A.
For 2-Color setting, the emissivity should be negligible. That makes me believe that different materials has different slope setting for the temp reading.
One thing to note is that, the sintering temp of TaC is around 1900-2000C. It was clear that the container was fully sintered with TGHT at 450A.
Will need to gather more data with different material to understand the slope setting better.
Try:
SiC at 1700C, slope at 1.04
ZrC at 1900C, slope at 104
Ta at 1900C, slope at 0.98.
Compare the data...
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