ASPERA Forum SiC ultra-stiff material for high performance Optics and Structures Stéphane CHAILLOT Oct 2011 ROSETTA NAC – 13 NOV 2009

BOOSTEC Company  A “S.A.S” with a capital of M€  85% hold by MERSEN & 15% by ASTRIUM  Present staff: 35 ( Bazet in Pyrénées France )  Turn over around 6 M€  26 years of SiC manufacturing experience  12 years of Space Optics and Structure experience

BOOSTEC 2011  Several large space projects have been successfully achieved … OSIRIS (Rosetta), ALADIN (Aeolus) and HERSCHEL for ESA, NIRSPEC (JWST) for ESA and NASA, ROCSAT 2 (Taiwan), THEOS (Thailand), GOCI-COMS (Korea), NAOMI – ALSAT 2 (Algeria) and NAOMI-SSOT (Chile) dedicated to earth observation, NAOMI-ASTROTERRA for SPOT IMAGE (4 cameras for future SPOT 6 and 7) PLEIADES focal plane for CNES, GAIA for ESO 7 “all in SiC” telescopes are now in successful operations in space  or still in progress … SENTINEL 2 and ATLID Earth Care, EUCLID, PLATO for ESA, NAOMI-KAZAKHSTAN earth observation,  Other optics and structure parts towards Large ground telescopes E-ELT, ESO New energies and new chemical engineering: heat exchangers, micro-reactors, … Big physics instruments, Neutrons, Lasers, Atomic force, RF, µWaves … Boostec is the only company in the world which is able to produce very large size space telescopes

BOOSTEC is able to produce up to 3.5 m length components

Bolting, Glueing, Brazing are qualified processes.

Boostec Silicon Carbide : Mature and industrial technology

SiC basics : A robust material at reasonable price for high performance applications SiC is produced in the world at large scale for numerous applications. SiC can be used in a large scale of temperature (20 K – 1200 K) without any corrosion or fatigue concerns. (High T°, Cryo conditions) Full reliability (mechanical, thermal chemical …) Complex and very large (up to 3,5m) shaped parts No porosity on optical faces SiC / metal or SiC/SiC assemblies

Why SiC for optics instrumentation ? Density (g/cm 3 ) Beryllium Silicon carbide Glass ceramics Thermal expansion (10 -6 /K) Beryllium Silicon carbide Glass ceramics Young modulus (GPa) Beryllium Silicon carbide Glass ceramics Thermal conductivity (W/m-K) Beryllium Silicon carbide Glass ceramics

Stiffness (E/ρ) Thermal stability (K/α) Beryllium Glass ceramics Silicon carbide Ideal material Why SiC for optics instrumentation ?

Low density Perfect isotropy No secundary phase Thermal conductivity Thermo-mechanical stability Large range and cryo compatibility Passiv thermal control (no gradient) High specific stiffness No mechanical fatigue No relaxation time Non sensitive to moisture and radiation Non sensitive to chemical agressiv environment High vacuum compatible Fully compatible with actual polishing technics

BOOSTEC SiC main characteristics Theoretical density kg/m 3 Apparent bulk density> kg/m 3 Open porosity0% Total porosity< 3.5% Coefficient of thermal expansion °C /°C Thermal conductivity at 20 °C180W/m.K Specific heat at 20 °C680J/kg.K Vickers hardness (500 g load)22GPa Mechanical strength (3 point bending at 20 °C)450MPa Compressive strength3000MPa Young modulus420GPa Poisson ratio0.16 K 1c toughness at 20 °C3.5MN.m -3/2 Electrical resistivity10 5.Ohm.m Feel free to ask for completed data-sheet

Realizations

Our SiC manufacturing process Manufacturing very large SiC parts

Our SiC manufacturing process Complexe and large SiC shapes

Performances

Thanks for your attention