Tem-per-ature dependence in Bragg edge neutron transmission measurements.

A systematic study has been carried out to investigate the neutron transmission signal as a function of sample tem-per-ature. In particular, the experimentally de-ter-mined wavelength-dependent neutron attenuation spectra for a martensitic steel at tem-per-atures ranging from 21 to 700°C are com-pared with simulated data. A theoretical description that includes the Debye-Waller factor in order to describe the tem-per-ature influence on the neutron cross sections was im-plemented in the software and used for the simulations.

Nondestructive residual stress depth profile analysis at the inner surface of small boreholes using energy-dispersive diffraction under laboratory conditions.

Energy-dispersive diffraction under both laboratory and synchrotron conditions was applied to study the hoop stress in the near-surface region of the inner wall of boreholes with a small diameter of 2 mm. By use of different X-ray beam cross sections for the sinψ measurements, it is demonstrated that the borehole-to-beam-diameter ratio must be considered in the evaluation. A beam cross section which is comparable to the borehole diameter reduces the slope of the -sinψ distributions and thus invalidates the result of stress analysis.

: a graphical user interface for the analysis of energy-dispersive diffraction data.

is a MATLAB-based graphical user interface for the convenient and versatile analysis of energy-dispersive diffraction data obtained at laboratory and synchrotron sources. The main focus of up to now has been on the analysis of residual stresses, but it can also be used to prepare measurement data for subsequent phase analysis or analysis of preferred orientation. The program provides access to the depth-resolved analysis of residual stresses at different levels of approximation.

Residual Lattice Strain and Phase Distribution in Ti-6Al-4V Produced by Electron Beam Melting.

Residual stress/strain and microstructure used in additively manufactured material are strongly dependent on process parameter combination. With the aim to better understand and correlate process parameters used in electron beam melting (EBM) of Ti-6Al-4V with resulting phase distributions and residual stress/strains, extensive experimental work has been performed. A large number of polycrystalline Ti-6Al-4V specimens were produced with different optimized EBM process parameter combinations.

3D mapping of crystallographic phase distribution using energy-selective neutron tomography.

Nondestructive 3D mapping of crystallographic phases is introduced providing distribution of phase fractions within the bulk (centimeter range) of samples with micrometer-scale resolution. The novel neutron tomography based technique overcomes critical limitations of existing techniques and offers a wide range of potential applications. It is demonstrated for steel samples exhibiting phase transformation after being subjected to tensile and torsional deformation.

Compensation of ring artefacts in synchrotron tomographic images.

Tomographic images are often superimposed by so called ring artefacts. Ring artefacts are concentric rings in the images around the center of rotation of the tomographic setup caused e.g.