Nov, 2023
Conference Paper
Publications
Showing 80 results for Author: Amir K. Ziabari
Nov, 2023
Journal
Enabling rapid X-ray CT characterisation for additive manufacturing using CAD models and deep learning-based reconstruction
Metal additive manufacturing (AM) offers flexibility and cost-effectiveness for printing complex parts but is limited to few alloys. Qualifying new alloys requires process parameter optimisation to produce consistent, high-quality components. High-resolution X-ray computed tomography (XCT) has not been effective for this task due to artifacts, slow scan speed, and costs. W…
Nov, 2023
Journal
Observation of spatter-induced stochastic lack-of-fusion in laser powder bed fusion using in situ process monitoring
Material produced via additive manufacturing (AM) continues to exhibit variable mechanical properties despite apparent optimization of processing parameters, inhibiting qualification efforts and limiting use in critical applications. Stochastic lack-of-fusion flaws may help explain this variability, but the origin of these seemingly random defects has to this point remaine…
Nov, 2023
Conference Paper
Physics guided machine learning for multi-material decomposition of tissues from dual-energy CT scans of simulated breast models with calcifications
We introduce a physics guided data-driven method for image-based multi-material decomposition for dual-energy computed tomography (CT) scans. The method is demonstrated for CT scans of virtual human phantoms containing more than two types of tissues. The method is a physics-driven supervised learning technique. We take advantage of the mass attenuation coefficient of dense…
Nov, 2023
ORNL Report
Oak Ridge National Laboratory Input to Laser Powder Bed Fusion Qualification of 316 Stainless Steel
The Advanced Materials and Manufacturing Technologies program is a multi-laboratory effort to bring advanced manufacturing to bear for nuclear applications, as well as to the greater industrial market. As part of this endeavor, the Advanced Materials and Manufacturing Technologies program, in concert with other standards bodies, is working to direct an accepted qualificati…
Nov, 2023
Journal
Method for Measurement of TRISO Kernel and Layer Volumes by X-ray Computed Tomography
Layer dimensions are key parameters for as-fabricated tristructural-isotropic (TRISO) particle fuel as well as for post-irradiation examination of particle performance. Layer thicknesses are typically measured by optical microscopy of the particle cross section near mid-plane, while layer volumes are estimated with serial sectioning and microscopy. This method for measurin…
Nov, 2023
Journal
Algorithm-Driven Advances for Scientific CT Instruments: From model-based to deep learning-based approaches
Multiscale 3D characterization is widely used by materials scientists to further their understanding of the relationships between microscopic structure and macroscopic function. Scientific computed tomography (SCT) instruments are one of the most popular choices for 3D nondestructive characterization of materials at length scales ranging from the angstrom scale to the micr…
Nov, 2023
Journal
Geometrical quasi-ballistic effects on thermal transport in nanostructured devices
We employ thermoreflectance thermal imaging to directly measure the steady-state two-dimensional (2D) temperature field generated by nanostructured heat sources deposited on silicon substrate with different geometrical configurations and characteristic sizes down to 400nm. The analysis of the results using Fourier’s law not only breaks down as size scales down, but it also…