Research in the area of gas processing of metal powders focus on two main areas, namely the characterising and modelling the flow during the industrial production of metal powder via High Pressure Gas Atomisation (HPGA) and the condensation of nano-precipitates from metal vapour dispersed in a low pressure inert gas. This latter is used to fabricate a range of nanostructured materials.
Facilities for the characterisation of industrial flows include:
• high speed image capture (typically 18,000 fps is utilised for characterising gas atomisation, although the instrument is capable of 400,000 fps)
• custom data processing software for batch processing of high speed video data
• Schlieren imaging
• analogue atomiser for studying gas only and 2-phase flow
• computational fluid dynamics modelling
For the production of nanostructured materials a facility unique with the UK has been commissioned within the Institute for Materials Research. Vapour condensation within an ultra-clean, inert gas, atmosphere is utilised to produce nanoparticulates and coated nano-powders in either natural or forced convection. In-situ compaction is then applied to produce monolithic nanocrystalline or nanocomposite materials. The forced gas synthesis technique can be used to produce metal-metal nanocomposites or metal-ceramic nanocomposites, the latter having either metallic or ceramic dispersed phases. Furthermore, the application of photocorrelation spectroscopy enables the particle size evolution to be followed continuously, in-situ and non-invasively.