Abstract
This paper represents the first application of small angle neutron scattering (SANS) to the study of precipitate nucleation and growth in β-Ti alloys in an attempt to observe both the precipitation process in-situ and to quantify the evolving microstructure that affects mechanical behaviour. TEM suggests that athermal ω can be induced by cold-rolling Gum metal, a β-Ti alloy. During thermal exposure at 400°C, isothermal ω particles precipitate at a greater rate in cold-rolled material than in the recovered, hot deformed state. SANS modelling is consistent with disc shaped nanoparticles, with length and radius under 6nm after thermal exposures up to 16h. Modelling suggests that the nanoprecipitate volume fraction and extent of Nb partitioning to the β matrix is greater in the cold-rolled material than the extruded. The results show that nucleation and growth of the nanoprecipitates impart strengthening to the alloy.
| Original language | English |
|---|---|
| Pages (from-to) | 146-156 |
| Number of pages | 11 |
| Journal | Journal of Alloys and Compounds |
| Volume | 623 |
| DOIs | |
| State | Published - Feb 25 2015 |
Funding
JC, VV, NGJ and DD would like to acknowledge funding from EPSRC under grant EP/H0004882/01. JC and MO would also like to acknowledge fellowship funding provided by JSPS . This work utilizes the Oak Ridge National Laboratory’s High Flux Isotope Reactor, which is sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy . We would like to thank Matthias Knop at Imperial, Mark Ward at the University of Birmingham and Richard Dashwood at Warwick University for their help with sample manufacture and preparation.
Keywords
- Metals and alloys
- Neutron scattering
- Precipitation Transmission Electron Microscopy, TEM
- Titanium alloys