Overview: Strong Metallic Alloys

The group is concerned with the development or improvement of metallic alloys to allow for more efficient use. The main project is the development of Pt-based alloys for high temperature applications in aggressive environments. As well as developing the alloys themselves, the group is also building a thermodynamic database so that the phases and their proportions can be calculated for different alloys. This will be an invaluable tool for future designers and will also facilitate further improvements to the alloys. Since there was very little phase diagram information, the group has had to undertake much experimental phase diagram work in order to obtain data for optimisation to build the database. The drivers for this part are Dr R. S?and Prof. L.A. Cornish and the work is ongoing at Mintek and Wits. The bulk properties are being studied under Prof. D. Comins at Wits. Prof. M.J. Witcomb is undertaking electron microscope studies at Wits, as is Prof. J. Neethling at NMMU. Prof. P. Ngoepe is undertaking modelling of PGM alloys at ULim, while Prof. K. Pruessner is involved with oxidation studies at Wits. Mr A. Mwamba, Ms W. Tshawe and Dr R. S?at Mintek also investigated the utilisation of the Pt-based alloys as EB-PVD coatings on cheaper substrates, as well as powder metallurgy components manufactured through water atomisation or mechanical alloying and subsequent sintering. Powder metallurgy work will continue at Mintek on alloys containing Pt and other PGMs as well.

A new area of interest to the group is corrosion phenomena. Our newest member, Mr J. van der Merwe, will be undertaking general corrosion studies at Wits. Mintek is also to embark on a major study regarding a high temperature corrosion phenomenon called metal dusting, funded by DST s Advanced Metals Initiative (AMI). This will see the advent of increased R&D on ferrous metals being done as part of a drive to diversify the activities of the Focus Area. The driver for this will be Mintek, which will be the hub for the AMI s Ferrous and Base Metals Development Network (FMDN). Dr R. S?currently co-ordinates one of the FMDN projects which is focussed on Metal Dusting.