S. Schmidt et al./ Acta Astronautica 55(2004)409-420 411 ==冒 Fig. 3. 5-axis winding machines. Fig. 2. CMC production by infiltration and pyrolysis of polymers 2. 2. Production capabilities pressures of up to 80 bars. Further, very success- ful test campaigns with radiation-cooled combustion Based on the current production by EADS in chambers were carried out in the small-thruster sec Friedrichshafen of carbon fibre reinforced plastics tor, whereby the material was able to demonstrate its (CFRP)for the protective payload fairing of Ariane 5 (Speldra and Syldra), liquid-polymer infiltration was versus the propellants and combustion products developed by DaimlerChrysler Research for, amongst other things, space components, hot structures, and 2. Manufacturing, process technique and non re-entry technologies destructive investigation (NDD) methods In order to build axisymmetric components such as nozzle extensions. combustion chambers, etc 2. LP- two 5-axis winding machines with dimensions 3200×10,000mm2and2000×5000mm2(Fig.3) mer route. The coated C-fibre bundle is impregnated sions 500/800 x 5000 mm? machines with dimen- The C/SiC is made as shown in Fig. 2 via the poly- as well as two 4-axis windi with a powder-filled polymer and laminated to form are available, in particular for 3D components prepregs Analogously to the manufacturing technique For the autoclave hardening of the components for fibre-reinforced plastics, the structure is laminated, order to provide them with the so-called green body, compacted in an autoclave and cross linked, and then various autoclaves are available for smaller compo- pyrolized without pressure and without moulding nents(1000 x 3000 mm")as well as for large-space tools at temperatures of 1300-1900 K in inert ga structures(3500 x 8500 mm2)in the Friedrichshafen For further compacting(depending on the desired production centre(Fig 4) porosity ) re-impregnation is effected with a suitable For high-temperature treatment, two pyrolysis polymer followed by pyrolysis. The component may furnaces for component sizes of up to 2.5 m in diame- then be coated optionally with an protection layer ter and 3 m in height are available(the Munich-based hanks to the consistent advanced development ECM company ) of the LPI Route over the past years, using a ew reinfiltration polymer permitted reducing the 2.3. NDI methods re-impregnation cycles by 50% while retaining the mechanical strength characteristics. Conse- In view of, compared to metals, significantly ly, it was possible to cut the production costs, in anisotropic ceramic composite structure, the non- icular for large-scale structures, by approx. 25% destructive testing of C/SiC components alreadyS. Schmidt et al. /Acta Astronautica 55 (2004) 409 – 420 411 Fig. 2. CMC production by in3ltration and pyrolysis of polymers. pressures of up to 80 bars. Further, verysuccess￾ful test campaigns with radiation-cooled combustion chambers were carried out in the small-thruster sec￾tor, wherebythe material was able to demonstrate its long-term stabilityand high chemical compatibility versus the propellants and combustion products. 2. Manufacturing, process technique and non destructive investigation (NDI) methods 2.1. LPI-process The C/SiC is made as shown in Fig. 2 via the poly￾mer route. The coated C-3bre bundle is impregnated with a powder-3lled polymer and laminated to form prepregs. Analogouslyto the manufacturing technique for 3bre-reinforced plastics, the structure is laminated, compacted in an autoclave and cross linked, and then pyrolized without pressure and without moulding tools at temperatures of 1300–1900 K in inert gas. For further compacting (depending on the desired porosity), re-impregnation is e;ected with a suitable polymer followed by pyrolysis. The component may then be coated optionallywith an protection layer. Thanks to the consistent advanced development of the LPI Route over the past years, using a new rein3ltration polymer permitted reducing the re-impregnation cycles by 50% while retaining the same mechanical strength characteristics. Conse￾quently, it was possible to cut the production costs, in particular for large-scale structures, byapprox. 25%. Fig. 3. 5-axis winding machines. 2.2. Production capabilities Based on the current production byEADS in Friedrichshafen of carbon 3bre reinforced plastics (CFRP) for the protective payload fairing of Ariane 5 (Speldra and Syldra), liquid-polymer in3ltration was developed byDaimlerChrysler Research for, amongst other things, space components, hot structures, and re-entrytechnologies. In order to build axisymmetric components such as nozzle extensions, combustion chambers, etc., two 5-axis winding machines with dimensions 3200 × 10; 000 mm2 and 2000 × 5000 mm2 (Fig. 3) as well as two 4-axis winding machines with dimen￾sions 500=800×5000 mm2 and 200=800×2000 mm2 are available, in particular for 3D components. For the autoclave hardening of the components in order to provide them with the so-called green body, various autoclaves are available for smaller compo￾nents (1000 × 3000 mm2) as well as for large-space structures (3500 × 8500 mm2) in the Friedrichshafen production centre (Fig. 4). For high-temperature treatment, two pyrolysis furnaces for component sizes of up to 2:5 m in diame￾ter and 3 m in height are available (the Munich-based ECM company). 2.3. NDI methods In view of, compared to metals, signi3cantly anisotropic ceramic composite structure, the non￾destructive testing of C/SiC components already