Ice767 (NG73): nebulized f.g. ice I + 3% by vol 1-micron Al2O3, mixed by manual tumbling

T = 220 K, P = 50 MPa, s = 2 MPa step (1)
T = 200 K, P = 50 MPa, s = 3 MPa step (2)
T = 200 K, P = 50 MPa, s = 4.5 MPa step (3)

 

Legend: Upper graph of each pair is motor speed V (proportional to edot); lower graph is load (in volts). Translate motor V to edot thus: V1.00 ≈ 6e-6/s ≈ 2%/hr. Load to stress translation for ice767 is roughly ____ MPa/mV, with a __ mV zero offset. Horizontal scale is time. 5000 ≈ 14 hrs.
     

e = 0.174

 

End of step (3). Looks like work hardening lasted not more than 1-2% strain since previous.

 

7/10/14 0938 hrs
e = 0.111

 

4% strain into step (3) and it still seems to be work hardening. Have to guess this is related to the alumina dust.

 

7/9/14 1737 hrs
e = 0.081

 

End of step (2) to start of step (3), again a 50% increase in stress. But this time edot has increased by a factor of ~3, meaning n is almost 3.

 

7/9/14 1030 hrs
e = 0.073

 

 

Last ~14 hrs of step (2); not that much hardening or softening.

 

7/9/14 0901 hrs
e = 0.054

 

~14 hrs of step (2), shows apparent hardening as edot drops over the first 1% or so of strain.

 

7/8/14 2323 hrs
e = 0.031

 

End of step (1) to start of step (2) at 50% higher stress. edot barely doubled, meaning n ≤ 2.

 

7/8/14 1042 hrs
e = 0.026

 

Step (1), most of step. Came to steady edot (top chart) without much strain hardening or softening, which is typical of GSS creep without grain growth.

Note that through 3% strain, this material is weaker than pure 3 x P-dropped ice. I'll create a plot...

7/8/14 0733 hrs