Sheared edge quality in the trimming of sheet metals

Examines the sheared edge quality of different automotive sheet metals resulting from the trimming process using experimental tooling and finite element modelling. The significant differences in burr, sliver and edge profile formation have been explained in terms of the strain distribution and tensile properties of the materials.

Compression and extrusion of metals using rotating dies

Experimental and theoretical investigations of compression and extrusion of metals with steadily or cyclically rotating dies were carried out. Reasonably simple models were produced by classical plasticity theory and analytical equations were developed to establish a theoretical basis for the associated phenomena. Analytical solutions agreed well with the experimental results.

Sulfur and heavy metals in biological tissue

The correlation between sulfur, metallothionein and heavy metals was investigated in biological samples from the aquatic environment. Samples of orange roughie, shark, goldfish and king crab were analysed for metals and sulfur. Results indicated that there was insufficient evidence to suggest any relationship between sulfur and total metals, but there was sufficient evidence to suggest a significant relationship existed between mercury and total sulfur in the biological tissues examined.

Dye-sensitized nanocrystalline solar cells incorporating ethylmethylimidazolium-based ionic liquid electrolytes

High-performance dye-sensitized solar cells incorporating electrochemically stable non-volatile electrolytes are especially desirable devices. In particular, ionic liquid systems based on ethylmethylimidazolium dicyanamide seem to be promising for this purpose. These have triggered our interest in the properties of further ethylmethylimidazolium-based ionic liquids with anions which are close relatives of dicyanamide. In this study, the effect of three different anions, tricyanomethanide, dicyanamide and thiocyanate, on the performance of dye-sensitized solar cells have been investigated. Both the short circuit photocurrent and conversion efficiency are increased with decreasing viscosity of the ionic liquids under comparable conditions. A conversion efficiency of 2.1% at 30% light intensity was observed for the cell containing the tricyanomethanide salt, which has lowest viscosity among the three ionic liquids, while efficiencies of 0.7% and 1.7% at the same light intensity were observed in the case of dicyanamide and thiocyanate salts, respectively, as an electrolyte.

Urban streetscape bryophytes and heavy metals

This thesis presents the first large scale examination of urban bryophytes in Australia in terms of species distribution, screening as hyperaccumulators and use as biomonitors. It provides baseline data to allow future comparison of the distribution of urban bryoflora with respect to arsenic and the associated contribution of cadmium, copper, zinc and lead.

Surface alloying of metals using fluid bed reactor

The use of fluidised bed reactors for surface alloying is reviewed. Research at Deakin has includes the use of chemical vapour deposition to form chromium rich layers on ferrous substrates, including stainless and tool steel grades. These layers can be modified to carbide or nitride if required by the end application. The deposition of aluminium and silicon has also been successfully achieved.

Structure and capacitive properties of porous nanocrystalline VN produced by NH3 reduction of V2O5

Vanadium nitride (VN) is currently one of the most promising materials for electrodes of supercapacitors. The structure and electrochemical properties of VN synthesized by temperature-programmed NH₃ reduction of V₂O₅ are analyzed in this paper. Vanadium nitride produced via this route has distinctive structural characteristics. VN mimics the shape of the initial V₂O₅ precursor indicating a pronounced direct attachment of nitride grains. The particles have domains of grains with a preferential orientation (texture). The large volume of pores in VN is represented by the range of 15−110 nm. VN demonstrates capacitive properties in three different types of aqueous electrolytes, 1 M KOH, 1 M H₂SO₄, and 3 M NaCl. The material has an acceptable rate capability in all electrolytes, showing about 80% of its maximal capacitance at a current load of 1 A/g in galvanostatic charging/discharging experiments. The capacitance of 186 F/g is observed in 1 M KOH electrolyte at 1 A/g. The previously reported negative effect of material loading on the capacitance is significantly suppressed. The observed electrochemical characteristics related to the application of this material in supercapacitors can be correlated with the crystalline structure of the nitride and the composition of its surface layer.

Effects of replication on measured S-N curves of metals

Replication, or repeated tests at the same stress amplitude, is used to provide statistical confidence in life data during the development of S-N curves. This paper discusses the effects of replication on the measurement of S-N curves and presents an alternative to traditional replication methods for the determination of S-N curves, particularly for the development of preliminary S-N curves. Using specimens made out of the extruded bars of a magnesium alloy, it is demonstrated that the S-N curve estimated using the data from non-replication tests is almost same as that from replication tests. The advantage of using non-replication fatigue tests is that it uses fewer specimens, in this instance, only half of that required for 50% replication fatigue test, to achieve the same estimation as that of the replication fatigue tests. Another advantage of using non-replication fatigue tests is that it can detect the non-linearity using limited specimens.

Influence of grain size on twinning in two hcp metals

Deformation twinning behaviour in differently grain sized samples of a commercial pure titanium and a magenisum alloy is investigated. In some aspects the phenomenology of twinning differs between the two materials while in others both materials show a similar response. Nucleation density per unit of nucleating interface and twin aspect ratio scale with applied stress. The impact of grain size on twin volume fraction is modelled analytically.

Nanograin metals and metallic multilayers produced by severe plastic deformation

This research has developed an improved understanding of the structure-property relationships, fabrication technology and deformation mechanism of light bulk ultrafine grained materials and metallic multilayered structure.

Nanocrystalline titanium to mesoporous anatase with high bioactivity

In present study, the formation of bioactive anatase on bulk titanium (Ti) by hybrid surface mechanical attrition treatment (SMAT) is reported. A commercial pure Ti plate first underwent SMAT in a vacuum for 1 h to produce a nanocrystalline layer with a thickness of about 30 µm, and then the nanocrystalline Ti (30 nm) was transformed into mesoporous anatase with a grain size 10 nm by chemical oxidation and calcination. The mesoporous anatase showed excellent bioactivity while being soaked in simulated body fluid, which could be attributed to the unique nanostructure on the SMAT Ti surface.