Redmore, Eleanor (2011)
M.Res. thesis, University of Birmingham.
The development of an effective ceramic conversion treatment of TIMETAL LCB (Ti-6.8Mo-4.5Fe-1.5Al) has been investigated. Various characterisation methods were used to analyse samples in order to identify the best process conditions including SEM, EDX, XRD, GDS, micro-indentation and scratch testing. A solution treatment temperature of 850°C was used as this is the appropriate temperature for the mechanism of solution treatment according to the β-transus temperature of this alloy. The results show that a solution treatment of 0.5 hours produces an acceptable thickness of oxygen hardened case, an almost equal hardness to that of a longer treatment and a far better oxide layer, than a longer treatment time did, in terms of adherence to the substrate. An aging temperature of 500°C was found to be the best as a lower temperature than this produced too thin an oxide layer and a higher temperature meant the oxide layer became exceedingly brittle. An aging time of 8 hours was found to be best as this gave good hardness, good performance in both static and dynamic loading and good wear resistance. The wear testing results show that the tribological properties of the TIMETAL LCB alloy have been significantly enhanced by the new ceramic conversion treatment specifically developed for beta alloys. The improved friction and wear properties can be attributed to the low-friction TiO\(^2\) outer oxide surface layer supported by a Ti\(^3\)O\(^5\) inner oxide layer and an oxygen diffusion hardened case up to a depth of ~70μm.
This unpublished thesis/dissertation is copyright of the author and/or third parties.
The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged.
Further distribution or reproduction in any format is prohibited without the permission of the copyright holder.
Repository Staff Only: item control page