3D Microstructural Characterization of Materials
Start Date
1-3-2012 9:45 AM
Description
Thermal protection systems are commonly comprised of composite materials, often with highly anisotropic micro/mesostructures. The heterogenous and anisotropic nature of the TPS materials can lead to significant thermal residual stresses at both room and high temperatures and complex deformation mechanisms. Three-dimensional characterization of material microstructures may provide important inputs modeling of both thermal residual stresses and deformation mechanisms.
Modern characterization techniques allow for direct three dimensional imaging of both as-processed and deformed materials at scales ranging from centimeters to nanometers, with the resolution of some applications approaching sub-nanometer. For example, electron tomography can reproduce 3D structures with nanometer resolution, though the field of view is limited to microns. Conversely, neutron diffraction can reproduce objects of many centimeters in size with a resolution (voxel size) of about 100-150 μm.
Analysis of deformed materials is generally more difficult, as contrast in signals between pristine and deformed materials is not always adequate. However, a number of characterization techniques may be utilized to analyze deformation mechanisms in two or three dimensions. These deformation mechanisms may then serve as inputs for material modeling, though accurate modeling of complex material system is non-trivial and generally requires significant computing power. Multiple case-studies will be discussed relating to modeling of experimental microstructures and direct two and three-dimensional imaging of deformation mechanisms.
3D Microstructural Characterization of Materials
Thermal protection systems are commonly comprised of composite materials, often with highly anisotropic micro/mesostructures. The heterogenous and anisotropic nature of the TPS materials can lead to significant thermal residual stresses at both room and high temperatures and complex deformation mechanisms. Three-dimensional characterization of material microstructures may provide important inputs modeling of both thermal residual stresses and deformation mechanisms.
Modern characterization techniques allow for direct three dimensional imaging of both as-processed and deformed materials at scales ranging from centimeters to nanometers, with the resolution of some applications approaching sub-nanometer. For example, electron tomography can reproduce 3D structures with nanometer resolution, though the field of view is limited to microns. Conversely, neutron diffraction can reproduce objects of many centimeters in size with a resolution (voxel size) of about 100-150 μm.
Analysis of deformed materials is generally more difficult, as contrast in signals between pristine and deformed materials is not always adequate. However, a number of characterization techniques may be utilized to analyze deformation mechanisms in two or three dimensions. These deformation mechanisms may then serve as inputs for material modeling, though accurate modeling of complex material system is non-trivial and generally requires significant computing power. Multiple case-studies will be discussed relating to modeling of experimental microstructures and direct two and three-dimensional imaging of deformation mechanisms.