DOAJ gelistet
Refine
Has Fulltext
- no (12)
Document Type
- Article (12)
Language
- English (12)
Is part of the Bibliography
- yes (12)
Keywords
- Ti-6Al-4V (2)
- X-ray computed tomography (CT) (2)
- additive manufacturing (2)
- infrared thermography (2)
- residual stress (2)
- selective laser melting (SLM) (2)
- specific surface area (2)
- ANFO (1)
- ASR-sensitive aggregate (1)
- Additive manufacturing (1)
- Electron back-scattered diffraction (1)
- Fiber-reinforced concrete (1)
- Microstructure and texture (1)
- Neutron diffraction (1)
- Nickel-based superalloy (1)
- Pseudo-Voigt fit function (1)
- Python (1)
- Residual stress (1)
- WAAM (1)
- X-ray (1)
- X-ray and (1)
- X-ray computed (1)
- X-ray imaging (1)
- X-ray refraction; (1)
- XCT (1)
- additive (1)
- additive manufacturing (AM) (1)
- alkali-silica reaction (ASR) (1)
- analyzer-based imaging (1)
- anisotropic fiber orientation (1)
- automated image processing (1)
- computed tomography (1)
- concrete (1)
- crack (1)
- damage quantification (1)
- data processing (1)
- defect detection (1)
- detection (1)
- diffraction (1)
- diffraction enhanced imaging (1)
- diffraction-elastic constants (1)
- electro-fused zirconia (1)
- explosives (1)
- healing (1)
- hybrid manufacturing (1)
- image registration (1)
- in situ monitoring (1)
- inverse analysis (1)
- iteration method (1)
- laser powder bed fusion (L-PBF) (1)
- laser-based additive manufacturing (1)
- manufacturing (AM) (1)
- micro computed tomography (XCT) (1)
- microcracking (1)
- monitoring (1)
- neutron (1)
- neutron diffraction (1)
- non-destructive evaluation (1)
- optical tomography (1)
- porosity (1)
- process (1)
- process monitoring (1)
- residual stress analysis (1)
- signal processing (1)
- solubility test (1)
- spacing (1)
- strain-free lattice (1)
- synchrotron X-ray diffraction (1)
- synchrotron x-ray refraction radiography (SXRR) (1)
- thermal expansion (1)
- tomography (XCT) (1)
Institute
Zirconia-based cast refractories are widely used for glass furnace applications. Since they have to withstand harsh chemical as well as thermo-mechanical environments, internal stresses and microcracking are often present in such materials under operating conditions (sometimes in excess of 1700 °C). We studied the evolution of thermal (CTE) and mechanical (Young’s modulus) properties as a function of temperature in a fused-cast refractory containing 94 wt.% of monoclinic ZrO2 and 6 wt.% of a silicate glassy phase. With the aid of X-ray refraction techniques (yielding the internal specific surface in materials), we also monitored the evolution of microcracking as a function of thermal cycles (crossing the martensitic phase transformation around 1000 °C) under externally applied stress. We found that external compressive stress leads to a strong decrease of the internal surface per unit volume, but a tensile load has a similar (though not so strong) effect. In agreement with existing literature on β-eucryptite microcracked ceramics, we could explain these phenomena by microcrack closure in the load direction in the compression case, and by microcrack propagation (rather than microcrack nucleation) under tensile conditions.
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.