arXiv subjects

Nikhil Prabhu

Publications and source records attributed to Nikhil Prabhu.

3 recordsLinked to original sources

arXiv2026

Subgrain-resolved Analysis of Degradation in Cu Metallization via Scanning 3DXRD and Thermomechanical Modeling

Metallization layers play a key role in the performance and reliability of modern power semiconductor devices. During short-circuit events, rapid heating of power metallization layers induces thermomechanical incompatibility stresses, which may contribute to material degradation and impact device performance. In this work, potential degradation hotspots associated with thermomechanical loading in Cu power metallization are investigated using a combined experimental--computational approach. Scanning three-dimensional X-ray diffraction measurements are coupled with thermomechanical crystal plasticity simulations to probe the evolution of grain-resolved plastic deformation during rapid cyclic loading. This integrated approach provides insight into the microstructural processes governing degradation hotspot formation, laying the groundwork for future microstructure-informed, physics-based reliability assessment of Cu metallization.

cond-mat.mtrl-sci↗

arXiv2025

Deformation mechanisms of L-PBF-processed Ti-6Al-4V investigated using a combined experimental and simulation approach

Despite the significant application potential of laser powder bed fusion (L-PBF) processed Ti-6Al-4V components, a detailed understanding of their deformation mechanisms remains limited. This study investigates the deformation behavior of the {α^\prime} and α phases in the as-built and heat-treated specimens, respectively, using in-situ high-energy X-ray diffraction (HEXRD) combined with crystal plasticity modeling. Both phases exhibited similar elastic anisotropy, with the highest modulus along \{00.2\} and the lowest along \{10.0\}, although the α phase consistently showed higher directional moduli than the {α^\prime} phase. Their plastic deformation responses differed markedly: in the as-built {α^\prime} phase, slip activation followed the sequence prismatic \rightarrow basal \rightarrow pyramidal I \langle c+a \rangle, whereas in the heat-treated α phase, the sequence was basal \rightarrow prismatic \rightarrow pyramidal I \langle c+a \rangle. Analyses of full width at half maximum (FWHM) and diffraction peak intensities further supported these observations. Finally, inverse modeling within a crystal plasticity framework was employed to determine slip family--specific critical resolved shear stresses (CRSS), revealing higher CRSS values in the {α^\prime} phase for all slip systems except the prismatic family.

cond-mat.mtrl-sci↗

arXiv2025

Incorporation of physics-based strengthening coefficients into phenomenological crystal plasticity models

The efforts associated with parametrization of continuum-based models for crystal plasticity are a significant obstacle for the routine use of these models in materials science and engineering. While phenomenological constitutive descriptions are attractive due to their small number of adjustable parameters, the lack of physical meaning of their parameters counteracts this advantage to some extent. This study shows that interaction/strengthening coefficients determined with the help of discrete dislocation dynamics simulations for use in physics-based formulations can also be used to improve the predictive quality of phenomenological models. Since the values of these parameters have been determined for most technologically relevant materials, the findings enable to improve the parametrization of phenomenological crystal plasticity models at no costs.

cond-mat.mtrl-sci↗