Browsing by Author "Wuhrer, R"

Now showing 1 - 7 of 7
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    Application of small-angle scattering to study the effects of moisture content on a native soy protein
    (Wiley-Blackwell, 2008-06) Kealley, CS; Elcombe, MM; Wuhrer, R; Gilbert, EP
    The nano-and microstructure of glycinin, a soybean protein, has been investigated as a function of moisture for moisture contents between 4 and 21 wt%. Glycinin exhibits peaks in the small-angle region whose positions show minimal change with X-rays for samples up to 13% moisture. However, the use of neutron scattering, and the associated enhancement in contrast, results in the Bragg peaks being well resolved up to higher moisture contents; the associated shift in peak positions between 4 and 21% moisture are consistent with the expansion of a hexagonal unit cell as a function of moisture content. A Porod slope of similar to-4 indicates that the interface between the 'dry' protein powder and the surrounding medium at a length-scale of at least 3 mm down to similar to 20 nm is smooth and sharp. Scanning electron microscopy indicates that the powders, with low moisture content, have a porous appearance, with the porosity decreasing and microstructure expanding as the moisture content increases. © 2008, Wiley-Blackwell.
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    Electron backscatter diffraction characterization of plasma immersion ion implantation effects in stainless steel
    (Elsevier, 2013-01-15) Davis, J; Short, KT; Wuhrer, R; Phillips, MR; Lumpkin, GR; Whittle, KR
    In these experiments plasma immersion ion implantation is utilised to simulate some of the radiation effects in a nuclear reactor environment. Scanning electron microscopy using the angular selective backscatter detector has revealed observable changes in crystallographic contrast after irradiation with helium ions. Further studies using electron backscatter diffraction in both plan and cross section view allow us to visualize the extent and depth of damage and observe differences in the behavior of different crystalline phases present in several grades of stainless steel. © 2012, Elsevier B.V.
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    An investigation of sol gel coated zirconia thin films on anodised titanium substrate by secondary ion mass spectrometry and scanning electron microscopy
    (Institute of Materials Engineering Australasia, 2007-12-12) Roest, R; Atanacio, AJ; Latella, BA; Wuhrer, R; Ben-Nissan, B
    Zirconia sol-gel-derived ceramic coatings have a variety of uses, due to their ease of production and ability to coat complex shapes. The sol-gel's nanocrystalline grain structure results in improved mechanical properties of the zirconia coating, which further aids their use in a variety of applications from thermal barrier coating to improved tribological properties on titanium substrates. Stabilised zirconia thin films were spin coated on anodised titanium substrates. The titanium was anodised in a dilute H3PO 4ZH2SO4 solution before spin coating with the zirconia sol gel. These films were then studied using secondary ion mass spectrometry (SIMS), to depth profile the elemental species through to the titanium substrate. In conjunction, scanning electron microscopy (SEM) and X-ray microanalysis were used to examine the craters formed by SIMS to gain an understanding of the diffusion gradient existing with the anodised titanium substrate and zirconia thin film. © 2007 Institute of Materials Engineering Australasia.
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    SEM and EBSD studies of ion implanted stainless steel
    (Committee of Asia-Pacific Societies of Microscopy, 2012-02-07) Davis, J; Short, KT; Wuhrer, R; Phillips, MR; Lumpkin, GR; Whittle, KR
    Research is currently in progress to determine the effect ion irradiation at varying energy and fluence has on the microstructure of several grades of stainless steel. Plasma Immersion Ion Implantation (PI3) and the Small Tandem for Applied Research (STAR) accelerator have been employed in this research to simulate some of the effects from a neutron irradiation environment using helium ions. The overall aim of the research is to eventually investigate other unique materials that have applications in both GenIV and fusion reactor programs and the Advanced Fuel Cycle Initiative (AFCI), e.g., inert matrix fuels, reactor core liners, and structural materials within the reactor (ODS materials). The main focus of this work will be to study the microstructure and understand grain boundary interactions, and how they relate to the tolerance of materials to damage.
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    Small punch test of LC4/SiCP metal matrix composites
    (Trans Tech Publications, 2010-09-17) Mak, J; Wuhrer, R; Humphries, SR; Booth, N; Heness, G; Yeung, WY; Wei, T; Qin, JN; Ouyang, QB; Zhang, D
    There have been growing demands of high performance metal matrix composites in advanced engineering applications in virtue of their high specific strengths. This paper is to report an assessment of the mechanical properties of LC4/SiCp metal matrix composites using an innovative testing technique, small punch test. The composite materials of this study were produced by stir casting method with particulate reinforcements of 7wt.% and 14wt.% of SiC respectively. Small punch testing was performed on the LC4 base alloy and the two composites materials. The small punch test is a relatively new mechanical testing technique capable of utilizing small disk-shaped samples to determine the mechanical properties of the test materials. In this study, the equivalent fracture strain, εqf of the LC4/SiCp MMCs was characterised and compared with the base alloy. The fracture mechanism of the test samples was examined using scanning electron microscopy. © Trans Tech Publications Ltd.
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    A solution for estimating the tensile yield strength from small specimens
    (ASTM Compass, 2013-05-24) Mak, J; Wei, T; Wuhrer, R; Yeung, WY; Heness, G; Zhang, D
    The small punch test is an innovative test that utilises small disc-shaped specimens to assess the mechanical behaviour of materials. The main advantage is the relatively small specimen size. In this article, a modified analytical solution for the small punch maximum bend strength is proposed that is based on classical plate theory. A clear linear relationship is observed between the tensile yield strength σYS and the small punch maximum bend strength σy for both alloys and metal matrix composites. © ASTM International.
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    Trends revealed by EBSD in ion implanted stainless steel
    (Australian Microbeam Analysis Society, 2013-02-06) Davis, J; Short, KT; Wuhrer, R; Phillips, MR; Lumpkin, GR
    In these experiments plasma immersion ion implantation is utilised to simulate some of the radiation effects in a nuclear reactor environment. Scanning electron microscopy using the angular selective backscatter detector has revealed observable changes in crystallographic contrast after irradiation with helium ions. Further studies using electron backscatter diffraction in both plan and cross section view allow us to visualize the extent and depth of damage and observe differences in the behavior of different crystalline phases present in several grades of stainless steel.