Postgraduate research with a materials element
Postgraduate research with a materials element – three short presentations
L to R: Geoff Williams, Rorie GIlligan, Mayeedul Islam, Mike Krachler
While there are currently no materials science or engineering undergraduate education programs in Western Australia, materials science research techniques continue to be used in postgraduate studies. Perth Branch heard short presentations from two students who are currently completing their PhD studies at Murdoch and Curtin Universities respectively. As there are no students at the final stages of their materials-related research at UWA, a brief summary of current materials research there was presented.
Rorie Gilligan from the School of Extractive Metallurgy at Murdoch spoke on uranium extraction from brannerite mineral. Brannerite (nominally UTi2O6) is relatively refractory in the ferric sulphate - sulphuric acid leaching process. This is a particular problem when brannerite is a minor constituent in otherwise leachable ore, as commonly occurs in Australian uranium deposits. Rorie’s presentation had its focus on the methods he used to characterise the solid components at various stages of his experimental leaching program. Brannerite as a metamict – a crystalline material that has become amorphous as a result of self-irradiation over millions of years. Rorie remarked that it was necessary to avoid automatic background subtraction in his X-ray diffraction analysis because this eliminates the characteristic profile of the amorphous material. In successive XRD traces made as the leaching preferentially dissolved the uranium, the anatase crystalline peaks from the remaining TiO2 became more prominent. Complementary SEM studies together with EDX analysis showed the subsequent precipitation of anatase during leaching, as well as the preferential leaching along areas of natural mineral alteration.
Mayeedul Islam from Curtin’s School of Chemical and Petroleum Engineering, summarised his studies into top-of-line (TOL) corrosion in pipelines. This occurs where there is stratified flow, with oil and water flowing the bottom part of a horizontal pipeline, with parallel flow of gas, water vapour and carbon dioxide in the space above. Corrosion occurs on the inside of the pipe within the vapour flow section, hence to term TOL corrosion, while the region carrying the liquid is protected against corrosion by the presence of MEG (monoethylene glycol), which is added to control hydrate formation as well as to reduce corrosion. Mayeedul’s research question concerned the effect of the MEG on TOL corrosion. His research was conducted using a laboratory test cell in which temperature and MEG concentration could be varied while corrosion on a steel test coupon was measured by weight change supplemented by SEM examination. Higher concentrations of MEG resulted in lower corrosion as measured by weight loss, but also resulted in a tendency toward pitting, which may be worse in terms of pipeline integrity.
Both presentations illustrated how methods associated with materials science are being widely used in studies of reactions and transformations of solid materials.
Research at UWA involving materials includes several projects relating to biomaterials and implants. Examples are 3-D printing of titanium mesh structures for made-to-measure bone replacements, and growth of hydroxyl-apatite onto titanium mesh surfaces to enhance bone fusion. Research on shape-memory alloys continues and now includes NiTi-Nb nanowire composites with unique high-strain capacity. Research of direct relevance to local resource extraction industries includes pipeline corrosion and testing procedures for non-metallic wear plates. Research into non-metallic materials includes fibre-reinforced adhesive joints. The term functional materials covers a wide range but essentially refers to design of materials with controllable properties for specific applications; battery storage materials and explosive crystallisation are of particular current interest at UWA.