This study investigated the feasibility of manufacturing bimetallic fuel pump bearings by Hot Isostatic Pressing (HIPping). The aim of the project was to reduce processing costs whilst maintaining or improving product quality. The process involved compacting, sintering and diffusion bonding Al 7wt%Si powder to 30 % leaded bronze. The pre-processing HIP conditions including surface preparation of the leaded bronze liner, powder size, degassing temperature and degassing dwell time, had a significant effect on the bond strength. By optimising the HIP conditions, it was then possible to achieve a highly compacted Al-Si casing that had bonded to the leaded bronze by forming a thin, uniform and continuous diffusion bond interface. The interface consisted of three intermetallic layers; Al2Cu, AlCu and Al2Cu3. Due to the brittle nature of the intermetallic layers, an increase in width resulted in a reduction in strength. An optimum bond width has been established and resulted in bond strengths up to four times greater than the current production bearings manufactured by flame spraying. The project developed a manufacturing process for powder HIP bearings that offered a potential cost saving of 18%.
Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:699130 |
Date | January 2016 |
Creators | Murray, Paul James |
Publisher | University of Birmingham |
Source Sets | Ethos UK |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Source | http://etheses.bham.ac.uk//id/eprint/7068/ |
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