143 citations · 349 across the 14 of their papers we have counts for
14 papers
Implicit Nucleation and Competitive Dynamics of Electrogenerated Hydrogen Nanobubbles
Nima Shakourifar, Nana Ofori-Opoku, Benzhong Zhao
Electrogenerated gas nanobubbles strongly influence the performance of electrochemical energy-conversion systems, yet their nucleation and early evolution remain poorly understood…
Efficient and quantitative phase field simulations of polycrystalline solidification using a vector order parameter
Tatu Pinomaa, Nana Ofori-Opoku, Anssi Laukkanen +1
A vector order parameter phase field model derived from a grand potential functional is presented as a new approach for modeling polycrystalline solidification of alloys. In this a…
Incorporating density jumps and species-conserving dynamics in XPFC binary alloys
Matthew J. Frick, Nana Ofori-Opoku, Nikolas Provatas
This work presents a consistent formulation of the structural phase-field-crystal model of substitutional binary alloys that allows for the description phases of unequal densities,…
Solidification Characteristics of Laser-Powder Bed Fused AlSi10Mg: Role of Building Direction
Hossein Azizi, Alireza Ebrahimi, Nana Ofori-Opoku +3
In this work, the effect of building direction on the microstructure evolution of laser-powder bed fusion (LPBF) processed AlSi10Mg alloy was investigated. The building direction,…
Self-consistent modeling of anisotropic interfaces and missing orientations: Derivation from phase-field crystal
Nana Ofori-Opoku, James A. Warren, Peter W. Voorhees
Highly anisotropic interfaces play an important role in the development of material microstructure. Using the diffusive atomistic phase-field crystal (PFC) formalism, we determine…
Simulation and analysis of -Ni cellular growth during laser powder deposition of Ni-based superalloys
Supriyo Ghosh, Nana Ofori-Opoku, Jonathan E. Guyer
Cellular or dendritic microstructures that result as a function of additive manufacturing solidification conditions in a Ni-based melt pool are simulated in the present work using…
On the primary spacing and microsegregation of cellular dendrites in laser deposited Ni-Nb alloys
Supriyo Ghosh, Li Ma, Nana Ofori-Opoku +1
In this study, an alloy phase-field model is used to simulate solidification microstructures at different locations within a solidified molten pool. The temperature gradient an…
Electrical Stressing Induced Monolayer Vacancy Island Growth on TiSe2
Husong Zheng, Salvador Valtierra, Nana Ofori-Opoku +5
To ensure the practical application of atomically thin transition metal dichalcogenides, it is essential to characterize their structural stability under external stimuli such as e…
Atomic-scale pathway of early-stage precipitation in Al-Mg-Si alloys
Vahid Fallah, Andreas Korinek, Nana Ofori-Opoku +4
Strengthening in age-hardenable alloys is mainly achieved through nano-scale precipitates whose formation paths from the atomic-scale, solute-enriched entities are rarely analyzed…
Complex order-parameter phase-field models derived from structural phase-field-crystal models
Nana Ofori-Opoku, Jonathan Stolle, Zhi-Feng Huang +1
The phase-field-crystal (PFC) modeling paradigm is rapidly emerging as the model of choice when investigating materials phenomena with atomistic scale effects over diffusive time s…
A Multi-Component Phase Field Crystal Model for Structural Transformations in Metal Alloys
Nana Ofori-Opoku, Vahid Fallah, Michael Greenwood +2
We present a new phase field crystal model for structural transformations in multi-component alloys. The formalism builds upon the two-point correlation kernel developed in Greenwo…
Simulation of Early-stage Clustering in Ternary Metal Alloys Using the Phase Field Crystal Method
Vahid Fallah, Nana Ofori-Opoku, Jonathan Stolle +2
Phase field crystal methodology is applied, for the first time, to study the effect of alloy composition on the clustering behavior of a quenched/aged supersaturated ternary Al all…
Phase field crystal modeling of early stage precipitation and clustering
Vahid Fallah, Jonathan Stolle, Nana Ofori-Opoku +2
A phase field crystal model is used to investigate the mechanisms of formation and growth of early clusters in quenched/aged dilute binary alloys, a phenomenon typically outside th…
A Phase Field Crystal Model of Phase and Microstructural Stability in Driven Nanocrystalline Systems
Nana Ofori-Opoku, Jeffrey J. Hoyt, Nikolas Provatas
We present a phase field crystal model for driven systems which describes competing effects between thermally activated diffusional processes and those driven by externally imposed…