Application of SiC/ C composite stirrer in suspension mixing system
Anna Dolata-Grosz, Werner Hufenbach, Józef Śleziona, Maik Gude, Andrzej Czulak
Quarterly No. 4, 2009 pages 373-379
DOI:
keywords: CMC, SiC/C stirrer, suspension manufacturing, properties
abstract Among the factors that have a considerable influence on the quality of metal composites reinforced with ceramic particles or short fibre, obtained via liquid-phase technologies, the most significant one is the quality of the composite suspension in-tended for casting. Its quality is determined by such factors as: the degree of gassing, a uniform reinforcing phase distribution and absence of chemical or solid impurities. In a mechanical stirring process, the quality of the mixture depends on a number of elements, the most important ones including the thermodynamic conditions (stable temperature and process pressure), physiochemical conditions (furnace atmosphere, chemical composition of the metal bath and reinforcing phase), and mechanical conditions (whirling speed, vortex shape and limitation of flow turbulence, and proper distribution of the reinforcing phase), the latter being the most difficult to implement and maintain their repeatability. The type of stirrer used in the process is re-sponsible for the overall mechanical conditions. Its shape, durability and chemical resistance determine, to a large degree, the quality of the composite mixture obtained. In article were presented assumptions and choose results of investigations connected with material selection and technology production of prototype's ceramic stirrer with destination to work in environment of liquid metal. Main aim of undertake investigations concerned designing, realization and technological verification of carbon fibres and ceramic matrix (SiC) stirrer used to production of composite suspensions. It was made an assumption that advantages of fibres composites with ceramic matrix, such as: thermal, mechanical and chemical will increase durability of stirrer in comparison with so far constructional solutions applied (metal, graphite). Project of stirrer (2D and 3D) was made in Solid Works programme. State of tensions analysis in blade with part of composites axis was executed with Finished Elements Method (MES). To producing of each elements of stirrer methods the winding, hand laminating and then polymer infiltration and pyrolysis technique, (PIP) were applied. Further laboratory tests of the SiC/C composite stirrer, designed and developed in the ILK (TU Dresden) have confirmed rightness of the design, assumptions regarding the thermal, mechanical and chemical resistance of the stirrer. Investigation was made within the confines of German-Polish cooperation between Institute of Lightweight Engineering and Polymer Technology in TU Dresden and Department of Alloys and Composite Materials Technology in the Silesian University of Technology.