Hardness tests
The hardness of the resins were measured using a Shore S1-D hardness tester, factory calibrated and checked against the supplied reference block.
Ten readings were taken from each resin disk. The highest and lowest readings were rejected and the average and standard deviation of the remaining eight are listed here. The hardness of ProbeMet and KonductoMet was not tested because of the inhomogeneity of the material.
Notes on Hardness
There are many scales used in the measurement of hardness. The unit most frequently used for resins is the Shore D scale. Some values from everyday objects (apart from Indium) are listed below:
Perspex
87.84 +/- 0.12
PVC
81.10 +/- 0.47
Indium
29.5 +/- 0.42
Yellow BIC Biro Case
81.5 +/- 0.25
| Epoxy Resin | Supplier Specification (If Known) | Shore D Hardness Avg (+/- Stdev) |
|---|---|---|
| EpoThin | 78 | 79.1 +/- 0.71 |
| EpoHeat | 85 | 80.1 +/- 0.50 |
| EpoxiCure (Room Temperature Cure) | 82 | 85.3 +/- 0.46 |
| EpoxiCure (Cured at 65'C) | 82 | 84.9 +/- 0.18 |
| TransOptic | - | 82.4 +/- 0.53 |
| SpeciFix-20 | 84 | 82.8 +/- 0.45 |
| EpoFix | 78 | 80.1 +/- 1.10 |
| Ciba Geigy MY778 & HY951 | - | 82.1 +/- 1.23 |
| Robnor Resin PX771c | 85 | 81.4 +/- 0.63 |
| Korapox 439 | - | 79.4 +/- 0.84 |
| Petropoxy | - | 85.3 +/- 0.78 |
| Domestic Rapid Set Araldite | - | 78.9 +/- 0.34 |
| Domestic Araldite | - | 78.5 +/- 0.76 |
| Varian Torr Seal | - | 83.8 +/- 0.97 |
| Epotek | 85 | 87.5 +/- 0.14 |
Nanoindentation Tests
Experiments were carried out by Wenzhong Zhu at the University of the West of Scotland. Two sets of indentation test were carried out on each specimen: One test batch of three test points at maximum load of 100 mN, the other batch of nine test points at a maximum load of 10 mN. The spacing between the indentation points is 100 µm.
Indent Load ~10mN
| Epoxy Resin | Youngs Modulus GPa Avg (+/- Stdev) | Hardness GPa Avg (+/- Stdev) |
|---|---|---|
| Korapox 439 | 2.335 +/- 0.050 | 0.084 +/- 0.001 |
| Transoptic | 2.737 +/- 0.056 | 0.094 +/- 0.002 |
| EpoThin | 3.495 +/- 0.098 | 0.126 +/- 0.007 |
Indent Load ~100mN
| Epoxy Resin | Youngs Modulus GPa Avg (+/- Stdev) | Hardness GPa Avg (+/- Stdev) |
|---|---|---|
| Korapox 439 | 2.323 +/- 0.039 | 0.079 +/- 0.001 |
| Transoptic | 2.777 +/- 0.015 | 0.090 +/- 0.002 |
| EpoThin | 3.506 +/- 0.016 | 0.123 +/- 0.001 |