The current research was commissioned to assess the feasibility of fabricating bonds between a range of commercially available titanium based aerospace alloys, using a low-cost direct resistance heating technique. A novel methodology has been devised and implemented which utilises a Gleeble facility to produce controlled resistance bonds. The optimisation of bonding parameters required to produce high quality joints is discussed i.e. the effects of surface treatment, pressure, time, temperature and environment. Optimised bond conditions have been defined for joining Ti 6/4 to itself and TNB (gamma titanium aluminide) to itself, negating the requirement for specialised surface treatments. In addition, a collaborative venture with Birmingham University was established to incorporate novel surface treatments using an electrical discharge machining procedure. In this respect, Ti 6/4 and TNB bonding couples utilising integral copper recast surface braze layers have been suitably optimised. Finally, the bonding of the dissimilar alloy combination Ti 6/4 to Ni-Ti (shape memory alloy) has been attempted using butt welding (with and without a Cu-Ni interlayer) and eutectic bonding procedures. However, bonding of this material combination proved difficult and this specific pairing may be incompatible using the present technique. Metallographic sections, chemical composition and micro-hardness traverses across all bond lines are presented as evidence of the form and integrity of the resulting joints. The mechanical performance of the bonds was assessed under monotonic tensile loading conditions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:639270 |
| Date | January 2005 |
| Creators | Tuppen, S. J. |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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