Browsing by Author "Brokmeier, HG"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Effect of texture heterogeneities on the shape memory properties of rolled Fe-Mn-Si SMA
    (Oldenbourg Verlag, 2009-09) Druker, AV; Sobrero, C; Malarria, J; Garbe, U; Brokmeier, HG; Bolmaro, RE
    We have investigated an Fe-30Mn-4Si shape memory alloy to clarify the effect, on the bulk texture, of the shear layers resulting from two different thermo-mechanical treatments. XR analysis has shown the existence of texture heterogeneity through the rolled sheet's thickness, due to the effect of friction between sheet and rolls. Neutron diffraction revealed that textured layers on the sheet's surface affect the whole volume. The texture found on the surface of the sheet rolled at 600 degrees C is the most favourable for the γ ->epsilon martensitic transformation which is the origin of the shape memory effect. Comparing these results with those obtained on sheets rolled at room temperature, we found that shear deformation gradients produce changes in the bulk material texture. Tensile tests initially induce the martensitic transformation in those grains favourably oriented. As a result, these favourable orientations disappear in the remnant austenite. © 2009, Oldenbourg Verlag
  • No Thumbnail Available
    Item
    StressTextureCalculator: a software tool to extract texture, strain and microstructure information from area-detector measurements
    (Wiley-Blackwell, 2011-06-01) Randau, C; Garbe, U; Brokmeier, HG
    Modern materials science diffractometers are generally equipped with area detectors that allow a high time efficiency to be achieved by simultaneously collecting the scattering pattern over large angular regions. These area-detector-based instruments, however, produce a huge amount of data, especially if they are located at large-scale neutron or synchrotron sources. The software StressTextureCalculator (STeCa) was designed to facilitate fast, easy and automated access to such area-detector data. Its outstanding features are direct calculation of diffraction patterns from different types of area-detector measurements, automatic data treatment and peak fitting using several implemented fit options. The resulting information on intensity, peak shift and broadening can then be exported into several data formats. These in turn can be used as input for a wide range of texture, stress and microstructure analysis software packages without additional prior treatment. © 2011, Wiley-Blackwell.