1. Diamond based Composites for Collimators Contribution to EuCard L. Weber Laboratory for Mechanical Metallurgy Ecole Polytechnique Fédérale de Lausanne (EPFL) CH-1015, Lausanne, Switzerland

2. Mechanical behaviour of Diamond MMCs Young’s modulus:4-point bending strength: 10.97 kHz Samples: ≈4x5.5x60 mm Modulus at RT, average of two modes Samples as for Young’s modulus Bending strength at RT

3. CTE of SIC Measurement parameters: 2 cycles 50…950°C Heating/cooling rate 5 Kmin -1 Holding time at extremes: 20 min Physical CTE approximated by a 2 nd order polynomial

4. Results on Mechanical behaviour of Diamond MMCs: Bending strength Ag-Si-D with >500 MPa bending strength (particle size 45 µm) CuD with a bending strength around 130 MPa (some plasticity, elastic limit much lower). Particle size 200 µm. AlD bending strength <30 MPa with large plastic deformation. Particle size 45 µm.

5. Results on Mechanical behaviour of Diamond MMCs: Young’s modulus MaterialVol. frac.Young’s modulus [GPa] Bending strength [MPa] Al_Diamond_10.164132 Al_Diamond_20.164332 Al_Diamond_30.294135 Cu_Diamond_10.77216136 Cu_Diamond_20.76204120 Ag-Si_Diamond_10.58317523 Ag-Si_Diamond_20.57317456 Ag-Si_Diamond_30.57326513 Low and very high volume fractions for Al and Cu-diamond composites, respectively, indicate presence of significant amounts of porosity

6. Results: CTE of SIC Samples Cis 1 and Cis 2

7. Results: CTE of SIC Sample traction

8. Results: CTE of SIC Sample CVD by Microcertec; z-direction is the growth direction CTE in-plane quite isotropic, somewhat lower in growth direction.

9. Results: CTE of SIC—comparison to literature Measurements on the present samples are significantly below literature values CTE best described by

10. Ag-Si_Diamond composites have promising properties Al- and Cu- based diamond composites suffer from porosity It may be interesting to evaluate the mechanical properties especially bending strength as a function of the diamond size. The CTE of SiC measured here is lower than the values indicated in the literature. Conclusion & Outlook