The main objectives of this project are to develop cost-effective manufacturing routes for CMC's including:
-development of semi-finished products
-development of various manufacturing routes such as lamination, liquid infiltration and filament winding
-continuous monitoring of materials and process quality to improve the product.
Economic and ecological aspects will also be considered during the project. The ultimate aim of the project is to produce larger demonstrator parts by the various manufacturing routes. The merits of these routes will be compared to each other and to existing routes.
To meet the aims of the project, several labscale production units have been designed and installed. It could be shown, that the manufacture of CMCs by polymer pyrolysis can use the equipment for production of fibre reinforced plastics. Nevertheless adaptation have to be made to meet the material requirements for precursors.
The possibility to use the prepreg manufacture route was shown and a prepregging line has been installed. The quality of the prepregs was mainly good, also the quality of the laminates after cross-linking. The filament winding process could be optimised for three different types of CMCs to enable the manufacture of large complex structures. The total production time could be reduced with only a slight change of the mechanical properties. Therefore a cost effective production route exists with the potential to manufacture large and complex structures. It could be shown that liquid infiltration technique is a suitable technique to produce even complex parts. The material data however are lower than material produced by filament winding technique with UD fibres, but for lot required applications the cost efficient production route will fulfil the requirements.
A quality assurance concept has been developed. The manufacture techniques have been evaluated for their technical performances, costs and ecological aspects. The materials have been evaluated thermophysical and mechanical resulting in a high amount of experience.
Several exhaust cones have been fabricated by filament winding, hand lamination and liquid infiltration technique. A shaker test on a demonstrator part could show the ability of the CMC material as a candidate material for turbine engines.
With the ability of three different manufacture routes the most cost effective route can be selected depending on geometry and shape of the structural part to be produced.
High performance ceramic matrix composites (CMC's) are currently produced by CVI. However, only simple shapes can be produced, the production times are long and strict quality control is required. This lead to high production costs and restricts their use to costly aerospace applications.
CMC's can be produced by methods other than CVI. However, to obtain material of comparable properties is difficult and very costly. A promising route is the infiltration and subsequent pyrolysis of Si-based polymers to form the ceramic matrix. Material with comparable properties may be achieved at a much reduced cost.
M60 1QD Manchester