1,720,964 research outputs found
input4MAUD : an efficient program for automatic two-dimensional diffraction image series input and/or batch refinement with MAUD
No full textIn materials science or applied crystallography, X-ray diffraction represents a versatile and useful method with which one can obtain the orientation of single crystals or even the texture of a polycrystalline material. When the investigated sample consists of many phases, or phases of low symmetry, it becomes difficult to measure pole figures from single diffraction peaks. A combined Rietveld-texture analysis with the program MAUD is perfectly suitable to deal with conditions of overlapping diffraction peaks, including those arising from different phases. Even though nearly no alternative to MAUD exists, it is not always easy to use. The input of a file series of two-dimensional diffraction images, for example from a texture measurement, can be time consuming since each individual image must be loaded manually, and only the newest beta version of MAUD allows semi-automated file input. The new program input4MAUD, which is presented in this paper, offers a much more efficient way to automate both single and batch file series input into MAUD as well as the preparation of basic batch refinements with MAUD. input4MAUD is written in Visual C++ and is currently available as a 32-bit statically compiled binary executable file for Windows
Calculation of anisotropic properties of dental enamel from synchrotron data
No full textObtaining information about the intrinsic structure of polycrystalline materials is of prime importance owing to the anisotropic behaviour of individual crystallites. Grain orientation and its statistical distribution, i.e. the texture, have an important influence on the material properties. Crystallographic orientations play an important role in all kinds of polycrystalline materials such as metallic, geological and biological. Using synchrotron diffraction techniques the texture can be measured with high local and angular resolving power. Here methods are presented which allow the spatial orientation of the crystallites to be determined and information about the anisotropy of mechanical properties, such as elastic modulus or thermal expansion, to obtained. The methods are adapted to all crystal and several sample symmetries as well as to different phases, for example with overlapping diffraction peaks. To demonstrate the abilities of the methods, human dental enamel has been chosen, showing even overlapping diffraction peaks. Likewise it is of special interest to learn more about the orientation and anisotropic properties of dental enamel, since only basic information is available up to now. The texture of enamel has been found to be a tilted fibre texture of high strength (up to 12.5×). The calculated elastic modulus is up to 155 GPa and the thermal expansion up to 22.3 × 10(-6)°C(-1)
Measurement of high-resolution recrystallization textures in nickel sheets using high-energy synchrotron radiation
No full textThe new developed "sweeping detector" techniques using high energy synchrotron radiation allow to measure textures and microstructures of materials and their change during heat treatment with high location and orientation resolution. Here we show these new methods applied to cold rolled and subsequently annealed nickel samples. The grain-resolved measurements show, impressively, many details of the recrystallization process which can otherwise not be seen. The results of these measurements can be the base for comprehensive recrystallization theories
Determination of multipeak textures with high-energy synchrotron radiation
No full textThe 'Moving Area Detector Method' with high energy synchrotron radiation allows to measure textures and microstructures of materials with high location and orientation resolution, e.g. so called Multipeak Textures. In this paper the measuring method is described shortly, as well as a description and the calculation of Multipeak Textures are given. A few examples of synthetic calculated Multipeak pole figures are shown
Determination of multipeak textures with high-energy synchrotron radiation
No full textThe 'Moving Area Detector Method' with high energy synchrotron radiation allows to measure textures and microstructures of materials with high location and orientation resolution, e.g. so called Multipeak Textures. In this paper the measuring method is described shortly, as well as a description and the calculation of Multipeak Textures are given. A few examples of synthetic calculated Multipeak pole figures are shown
Measurement of high-resolution recrystallization textures in nickel sheets using high-energy synchrotron radiation
No full textThe new developed "sweeping detector" techniques using high energy synchrotron radiation allow to measure textures and microstructures of materials and their change during heat treatment with high location and orientation resolution. Here we show these new methods applied to cold rolled and subsequently annealed nickel samples. The grain-resolved measurements show, impressively, many details of the recrystallization process which can otherwise not be seen. The results of these measurements can be the base for comprehensive recrystallization theories
Anisotropic local physical properties of human dental enamel in comparison to properties of some common dental filling materials
No full textObjective. A major aspect in evaluating the quality of dental materials is their physical properties. Their properties should be a best fit of the ones of dental hard tissues. Manufacturers give data sheets for each material. The properties listed are characterized by a specific value. This assumes (but does not prove) that there is no direction dependence of the properties. However, dental enamel has direction-dependent properties which additionally vary with location in the tooth. The aim of this paper is to show the local direction dependence of physical properties like the elastic modulus or the thermal expansion in dental hard tissues. With this knowledge the ‘perfect filling/dental material' could be characterized. Materials and method. Enamel sections of ∼400–500 μm thickness have been cut with a diamond saw from labial/buccal to palatal/lingual (canine, premolar and molar) and parallel to labial (incisor). Crystallite arrangements have been measured in over 400 data points on all types of teeth with x-ray scattering techniques, known from materials science. Results. X-ray scattering measurements show impressively that dental enamel has a strong direction dependence of its physical properties which also varies with location within the tooth. Dental materials possess only little or no property direction dependence. Therefore, a mismatch was found between enamel and dental materials properties. Conclusion. Since dental materials should possess equal (direction depending) properties, worthwhile properties could be characterized by transferring the directional properties of enamel into a property ‘wish list' which future dental materials should fulfil. Hereby the ‘perfect dental material' can be characterized
Recrystallization texture and microstructure in Ni and AlMg1Mn1 determined with high-energy synchrotron radiation
No full textThe newly developed "sweeping detector" technique with high energy synchrotron radiation allows to measure textures and microstructures of materials with high location and orientation resolution. This method was applied to hot rolled aluminium manganese alloys and to rolled nickel samples in different recrystallization stages. The grain-resolved measurements show, impressively, many details of the recrystallization process which can otherwise not be seen. That can be the base for comprehensive recrystallization theories
Recrystallization texture and microstructure in Ni and AlMg1Mn1 determined with high-energy synchrotron radiation
No full textThe newly developed "sweeping detector" technique with high energy synchrotron radiation allows to measure textures and microstructures of materials with high location and orientation resolution. This method was applied to hot rolled aluminium manganese alloys and to rolled nickel samples in different recrystallization stages. The grain-resolved measurements show, impressively, many details of the recrystallization process which can otherwise not be seen. That can be the base for comprehensive recrystallization theories
New insights in prism orientation within human enamel
No full textThe knowledge about the orientation of the prisms in human dental enamel is mainly based on morphological observations (light optical, SEM, etc.). Hence there are many schematic drawings, showing the orientation as seen in the microscope. Locally resolved direct measurements of the orientations, proofing the observations, have not been done in detail up to now. X-ray diffraction methods adapted from material science are used in this study, providing directly the orientation of the crystallites in the examined positions. Hereby new and better detailed information was obtained, showing the orientation of the prisms and giving information about their intrinsic structure. Based on the measurements, existing prism orientation models can be enhanced and two structural suggestions can be made, showing possible inner building principles for the prisms. Future planned measurements will even allow deciding which of the two models is more likely
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