Ladder development update

Results from SiC 01 test

Profile from SiC 03

Mechanical properties of foams

SiC 01- Sample Cool Down

•Sample cooled down down to -38oC over a period of 175min.•3 plots taken at -38 with 30min interval between each.•2 further plot taken at -40 with 15min gap.•Final plot taken when pressure was released (during this the temperature

changed from -38.3 to -37.2).

SiC 01- Profile Plots

Top two plots show 2D profiles of SiC 01 at 21.3oC and -40.6oC.Bottom left plot is the difference between the two.

SiC 01- Results Table

Time (min) Temp (oC) Max Z Displacement

(microns)

Min Z Displacement

(microns)

X co-ordinate for Max

(microns)

X co-ordinate for Min

(microns)

Magnitude of displacement

(microns)

0 21.3 4.50 -93.75 5000 133000 98.24

150 -35.2 4.23 -105.82 7000 135000 110.04

175 -38 3.99 -107.55 5000 135000 111.54

192 -38.5 3.93 -106.25 7000 135000 110.18

216 -38.3 4.23 -106.61 7000 135000 110.83

248 -40.5 3.81 -108.28 5000 133000 112.09

262 -40.6 3.90 -109.23 7000 135000 113.12

272 -38.3 -37.2 4.25 -111.56 7000 135000 115.85

Numbers high lighted in red where used in plots shown on the previous slide

SiC 03

High spot at 568 microns due to dirt on the surface.Low spot comes from gap in the Si and the sensor picking up a signal from the Al sample holder. Z displacement magnitude approximately 500 micorns.

SiC 03 - Glue pillars

LCD microscope output from laser shows difference between inner and outer glue pillars

Outer Edge Inner

Si as seen by laser microscope

Basic model consists of interconnecting open celled cubes and, if structure isdominated by wall bending failure, then mechanical properties follow scale laws.For elastic modulus:

Constant of proportionality has been shown to be close to unity in experiment andnumerical simulation.Simon Canfer is now testing a selection of SiC and RVC to test thistheory. The full list of mechanical properties that can be determined are:1. Elastic modulus under compression2. Poisson's ratio under compression3. Flexural strength To test under tension will require making samples in different geometries.Thermal properties that can be tested are:1. Coefficient of thermal expansion2. Moisture absorption

Mechanical Properties of Foams

€

E~

E s∝ρ~

ρ s

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⎝

⎜ ⎜

⎞

⎠

⎟ ⎟

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