TY  - JOUR
A1  - Mishurova, Tatiana
A1  - Cabeza, Sandra
A1  - Artzt, Katia
A1  - Haubrich, Jan
A1  - Klaus, Manuela
A1  - Genzel, Christoph
A1  - Requena, Guillermo
A1  - Bruno, Giovanni
T1  - An Assessment of Subsurface Residual Stress Analysis in SLM Ti-6Al-4V
JF  - Materials
N2  - Ti-6Al-4V bridges were additively fabricated by selective laser melting (SLM) under different scanning speed conditions, to compare the effect of process energy density on the residual stress state. Subsurface lattice strain characterization was conducted by means of synchrotron diffraction in energy dispersive mode. High tensile strain gradients were found at the frontal surface for samples in an as-built condition. The geometry of the samples promotes increasing strains towards the pillar of the bridges. We observed that the higher the laser energy density during fabrication, the lower the lattice strains. A relief of lattice strains takes place after heat treatment.
KW  - selective laser melting
KW  - additive manufacturing
KW  - heat treatment
KW  - Ti-6Al-4V
KW  - synchrotron X-ray diffraction
KW  - residual stress
Y1  - 2017
U6  - https://doi.org/10.3390/ma10040348
SN  - 1996-1944
VL  - 10
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Cabeza, Sandra
A1  - Mishurova, Tatiana
A1  - Garcés, Gonzales
A1  - Sevostianov, Igor
A1  - Requena, Guillermo
A1  - Bruno, Giovanni
T1  - Stress-induced damage evolution in cast AlSi12CuMgNi alloy with one- and two-ceramic reinforcements
JF  - Journal of materials science
N2  - Two composites, consisting of an as-cast AlSi12CuMgNi alloy reinforced with 15 vol% Al2O3 short fibres and with 7 vol% Al2O3 short fibres + 15 vol% SiC particles, were studied. Synchrotron computed tomography disclosed distribution, orientation, and volume fraction of the different phases. In-situ compression tests during neutron diffraction in direction parallel to the fibres plane revealed the load partition between phases. Internal damage (fragmentation) of the Si phase and Al2O3 fibres was directly observed in CT reconstructions. Significant debonding between Al matrix and SiC particles was also found. Finally, based on the Maxwell scheme, a micromechanical model was utilized for the new composite with two-ceramic reinforcements; it rationalizes the experimental data and predicts the evolution of all internal stress components in each phase.
Y1  - 2017
U6  - https://doi.org/10.1007/s10853-017-1182-7
SN  - 0022-2461
SN  - 1573-4803
VL  - 52
SP  - 10198
EP  - 10216
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Nadammal, Naresh
A1  - Cabeza, Sandra
A1  - Mishurova, Tatiana
A1  - Thiede, Tobias
A1  - Kromm, Arne
A1  - Seyfert, Christoph
A1  - Farahbod, Lena
A1  - Haberland, Christoph
A1  - Schneider, Judith Ann
A1  - Portella, Pedro Dolabella
A1  - Bruno, Giovanni
T1  - Effect of hatch length on the development of microstructure, texture and residual stresses in selective laser melted superalloy Inconel 718
JF  - Materials & Design
N2  - In the present study, samples fabricated by varying the deposition hatch length during selective laser melting of nickel based superalloy Inconel 718 were investigated. Microstructure and texture of these samples was characterized using scanning electron microscopy, combined with electron back-scattered diffraction, and residual stress assessment, using neutron diffraction method. Textured columnar grains oriented along the sample building direction were observed in the shorter hatch length processed sample. A ten-fold increase in the hatch length reduced the texture intensity by a factor of two attributed to the formation of finer grains in the longer hatch length sample. Larger gradients of transverse residual stress in the longer hatch length sample were also observed. Along the build direction, compressive stresses in the shorter hatch length and negligible stresses for the longer hatch length specimen were observed. Changes to the temperature gradient (G) in response to the hatch length variation, influenced the G to growth rate (R) ratio and the product GxR, in agreement with the microstructures and textures formed. For the residual stress development, geometry of the part also played an important role. In summary, tailored isotropy could be induced in Inconel 718 by a careful selection of parameters during selective laser melting.
KW  - Additive manufacturing
KW  - Nickel-based superalloy
KW  - Microstructure and texture
KW  - Residual stress
KW  - Electron back-scattered diffraction
KW  - Neutron diffraction
Y1  - 2017
U6  - https://doi.org/10.1016/j.matdes.2017.08.049
SN  - 0264-1275
SN  - 1873-4197
VL  - 134
SP  - 139
EP  - 150
PB  - Elsevier
CY  - Oxford
ER  -