Powder and liquid based processing of novel dispersion strengthened copper alloys for fusion applications

Nanostructured oxide dispersion strengthened (ODS) copper alloys exhibit a remarkable range of properties; high thermal conductivity, excellent irradiation resistance, high temperature thermal stability and high mechanical strength. These properties make them promising candidates for heat-sink materials for nuclear power. In order to achieve the desired performance of the ODS copper it is necessary to control the formation of the fine-scale, stabilising nano-clusters of oxide particles. This is achieved by control of the processing conditions, standard melting and casting techniques are unable to give a good uniformity of the dispersed particles, and so advanced processing solutions are sought. These routes are being developed as an alternative to the commercially available Cu-Al2O3 alloy that utilises internal oxidation during casting and heat-treatment.

The project is in collaboration with Culham Centre for Fusion Energy and aims to develop a processing capability for these materials primarily through powder metallurgy and spray forming routes, with investigation of the microstructure and nanostructure at each stage of the process. Characterisation of the dispersed particles by TEM analysis and other techniques during the stages of processing will be coupled with conventional and micro-mechanical testing. It is intended that this information will allow the mechanical response of the alloys to be rationalised, leading to identification of the optimum processing and material combinations to give microstructural stability and mechanical properties suitable for nuclear power applications.