Ceramic cores are utilised during turbine blade manufacture to develop cooling channels within the finished component. These cores, fabricated by ceramic injection moulding, must possess an array of properties to ensure minimal defect development during casting. The carrier system, powder interactions and component forming, critical in ceramic injection moulding, have been investigated within this project. The binder systems were developed using paraffin wax, ethylene vinyl acetate and polyethylene with stearic acid incorporated as a surfactant. Binder system development illustrated that a wide range of melting, rheological and mechanical properties could be produced by binder blending. The moulding success was improved by feedstock optimisation, with optimal surfactant levels determined between five and ten ‘layers’ upon the powder surface. Optimisation maximised the achievable ceramic solids loading, measured and estimated by density and rheological methods. Binder systems illustrating a good resistance to fracture with adequate flow characteristics have been shown to successfully form complex cores to high yields. Success in component forming was limited by feedstock fluidity, final components were more prone to crack development when the binder system had reduced crack resistance and success of the wicking process was limited in some systems by formulation with proposed mechanisms explained.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:687567 |
| Date | January 2016 |
| Creators | Standring, Tom |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/6804/ |
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