Ceramic Matrix Composites: A Challenge in Space‐Propulsion Technology Applications

Abstract

Various technology programs in Europe are concerned, besides developing reliable and rugged, low‐cost, throwaway equipment, with preparing for future reusable propulsion technologies. One of the key roles for realizing reusable engine components is the use of modern and innovative materials. One of the key technologies that concerns various engine manufacturers worldwide is the development of fiber‐reinforced ceramics—CMCs (ceramic matrix composites). The advantages for the developers are obvious–the low specific weight, the high specific strength over a large temperature range, and their great damage tolerance compared with monolithic ceramics make this material class extremely interesting as a construction material. Over the past few years, the EADS‐ST Company (formerly DASA) has, together with various partners, worked intensively on developing components for hypersonic engines and liquid rocket propulsion systems. In the year 2000, various hot‐firing tests with subscale (scale 1:5) and full‐scale nozzle extensions were conducted. In this year, a further decisive milestone was achieved in the sector of small thrusters, and long‐term tests served to demonstrate the extraordinary stability of the C/SiC material. Besides developing and testing radiation‐cooled nozzle components and small‐thruster combustion chambers, EADS‐ST worked on the preliminary development of actively cooled structures for future reusable propulsion systems. In order to get one step nearer to this objective, the development of a new fiber composite was commenced within the framework of a regionally sponsored program. The objective here is to create multidirectional (3D) textile structures combined with a cost‐effective infiltration process. Besides material and process development, the project also encompasses the development of special metal/ceramic and ceramic/ceramic joining techniques as well as studying and verifying nondestructive investigation processes for the purpose of testing components.

Stochastic Virtual Tests for High-Temperature Ceramic Matrix Composites

“…and even higher temperatures are sought (51)(52)(53). The tests must also have resolution comparable to the scale of the heterogeneities and damage events that control material performance.…”

Modal acoustic emission of damage accumulation in C/C–SiC composites with different fiber architectures

“…Carbon fiber reinforced silicon carbide (C/SiC) composites have made it into several high-temperature aerospace applications, like nozzle extensions, combustion chamber components and thermal protection panels for re-entry [1,2]. The Institute of Structures and Design of the German Aerospace Center (DLR) has been continuously working on advanced C/C-SiC composites for future thermal protection and space propulsion systems [3,4].…”

Tensile testing of materials at high temperatures above 1700 °C with in situ synchrotron X-ray micro-tomography

“…The engineering challenges in developing these materials are further escalated by, for example, the need to design fine leading edges (radii as small as 1 mm) and integrated actively cooled walls for use along hypersonic flow paths, which can experience extremely high thermal gradients. 2 Of the available CMC materials, textile composite structures with 3D woven carbon or SiC fibers embedded within a chemical vapor infiltrated SiC matrix demonstrate the best thermal and mechanical properties for these applications. [3][4][5] Weak interfaces, engineered using boron nitride (BN) or pyrolytic carbon coatings between the fibers and matrix, are used to enable fiber-bridging mechanisms for damage tolerance; the resulting difference in the strain to cause matrix and a) Author to whom correspondence should be addressed.…”