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CMC Technology and Structures

CMC-Engineering

The institute of structures and design has achieved an internationally recognized status regarding the development and manufacture of CMC lightweight structures. The basis for this work is the cost efficient liquid silicone infiltration process (LSI), which has been developed at DLR since the late 1980`s, and the resulting C/C-SiC materials as well as the realization of a number of challenging C/C-SiC components and structures.

With this special CMC technology and its engineering competence, DLR has been involved in all relevant space programs in Germany and Europe (ESA):

HYTEX	National hypersonic technology program. Development of a C/C-SiC intake ramp
CETEX	Manufacture of a C/C-SiC thermal protection system for the reentry capsule Express
Hot structures	Technology program for the development of joining technologies for fibre reinforced ceramics
FESTIP	Development of a C/C-SiC thermal protection system for a one stage space vehicle
TETRA	Development of a thermally extremely loaded (Tmax. = 1800 °C) C/C-SiC nose cap for the NASA experimental space craft X-38
FOTON	Development and reentry test of a new concept of a C/C-SiC thermal protection system for spacecraft
SHEFEX	Development of an extremely loaded (Tmax. = 1900 °C), cost efficient thermal protection system on the basis of flat C/C-SiC panels
EXPERT	Development of a C/C SiC nose cap (current project)

In the framework of national and international research programs, as well as in bilateral projects with industrial partners, a multitude of successful developments in the field of friction materials, like high performance ceramic brake discs and brake pads, led to serial products, manufactured by industrial partners under licence of DLR. As an example, the cooperation with Schindler Elevator Ltd. led to the serial introduction of C/C-SiC brake pads for high performance elevators.

CMC engineering

The strong point of the department is the closed engineering chain, which is the basis for the realization of tailored C/C-SiC materials for challenging components and structural parts: 

• Material development 
• Process development
• Ceramic design 
• Dimensioning and analysis (FEM)
• Manufacture of full-scale prototypes 
• Quality assurance and component qualification

For the material and process development, different laboratory furnaces as well as relevant methods for analysis (TG, DSC, scanning electron microscop, optical microscope with heating device up to 1700 °C, X-Ray diffractometer, dilatometer) are available. For design and analysis, modern CAD and FEM systems (Ansys, Unigraphics) are used. For the component development, large furnaces for pyrolysis and siliconization (OPUS 900) are available, with which even large CMC structures up to 1m in length can be realized. The quality assurance system is based on extensive process control and documentation as well as on destructive and nondestructive testing methods (air and water coupled ultrasonic, computer tomography, lock in thermography, photogrammetry, sound emission)