mohsenzaeem's blog

Solidification phenomenon has been an integral part of the manufacturing processes of metals, where the quantification ofstochastic variations and manufacturing uncertainties is critically important. Accurate molecular dynamics (MD) simulations ofmetal solidification and the resulting properties require excessive computational expenses for probabilistic stochastic analyseswhere thousands of random realizations are necessary.

I am happy to share with you our recent paper on kinetic phase-field modeling of non-equilibrium crystal growth, which is just published in Acta Materialia, it is open access:

S. Kavousi, V. Ankudinov, P. K. Galenko, M. Asle Zaeem. Atomistic-informed kinetic phase-field modeling of non-equilibrium crystal growth during rapid solidification. Acta Materialia 253 (2023) 118960 (11 pages).

We present the first mixed mode phase-field model of ductile fracture. The contribution of crack opening and shearing deformations to the propagation of a crack is expressed by introducing two phase fields. Constitutive relations are then introduced to couple and distinguish these phase fields. Special attention is given to the maximum shear stress and its effect on the development of fractures. The proposed model is validated by tensile testing experiments found in the literature on Al 2024 T-351.

This work presents a modified phase-field model for accurate coupling of phase transformation and cracking in shape memory ceramics. The existing phase-field models underestimate the elastic response at the beginning of the mechanical response. We modified the chemical free energy to control the rate of phase transformation and consequently obtain a physical elastic response before initiation of phase transformation. First, the forward and reverse martensitic phase transformation in a superelastic single crystal 3 mol% yttria-stabilized tetragonal zirconia is studied.

Large deformation of shape-memory polymer-based lattice metamaterials. International Journal of Mechanical Sciences (2022) 107593  

A PostDoc/Research Associate Position is available immediately at Colorado School of Mines. The applicants should have a PhD degree in Mechanical Engineering, Materials Science or a relevant field, with a strong background in phase-field modeling and/or MD simulations, especially in the area of diffusionless phase transformation and ferroelasticity. Knowledge of machine learning and data analysis is a plus. Interested candidates should send their CV with 2-3 of their recent and reverent publications to zaeem@mines.edu (Prof.

G. Azizi, S. Kavousi, and M. Asle Zaeem. Interactive effects of interfacial energy anisotropy and solute transport on solidification patterns of Al-Cu alloys. Acta Materialia 231 (2022) 117859 (15 pages). 

A PostDoc/Research Associate Position is available immediately at Colorado School of Mines. The applicants should have a PhD degree in Mechanical Engineering, Materials Science or a relevant field, with a strong background in MD simulations and/or phase-field modeling. The project involves developing new models for diffusionless phase transformation and ferroelasticity. Knowledge of machine learning and data analysis is a plus. Interested candidates should send their CV with 2-3 of their recent and reverent publications to zaeem@mines.edu (Prof.

A PostDoc/Research Associate Position is available immediately at Colorado School of Mines. The applicants should have a PhD degree in Mechanical Engineering, Materials Science or in a relevant field, with a strong background in DFT calculations, MD simulations and/or phase-field modeling. Project involves developing new models for diffusionless phase transformation and ferroelasticity. Knowledge of machine learning and data analysis is a plus.

In this work, superelastic and shape memory properties of single crystalline and polycrystalline yttria stabilized tetragonal zirconia (YSTZ) nanoparticles are studied by atomistic simulations. N. Zhang and M. Asle Zaeem. Superelasticity and shape memory effect in zirconia nanoparticles. Extreme Mechanics Letters 46 (2021) 101301 (8 pages).

A modified phase-field model for fracture is presented which includes the material strength and cleavage planes to quantitatively predict the crack propagation path and the mechanical response in polycrystalline brittle materials. Computational Materials Science 197 (2021) 110642 (11 pages).

Mechanical performance of silicon nanopillars with homogeneous and gradient nanotwinned structures are investigated through a series of molecular dynamics simulations. The most observed Σ3 twin boundary (TB) with two preferable (lowest surface energy) planes of {111} and {001} are used to generate homogeneous and gradient nanotwinned structures. Simulations of compression and tension of nanotwinned pillars reveal an extra strengthening behavior due to the addition of Σ3 TBs when compared to the single crystalline nanopillar without any TBs.

Dear iMechanica colleagues, I am pleased to share with you our newest paper on qauntitative prediction of rapid solidification. S. Kavousi, B. Novak, D. Moldovan, and M. Asle Zaeem. Quantitative prediction of rapid solidification by integrated atomistic and phase-field modeling.

The effects of applied load on the formation and reorientation of deltahydrides in alpha-zirconium matrix are studied by a multiphase field model.

(open access) C. Cissé and M. Asle Zaeem. An asymmetric elasto-plastic phase-field model for shape memory effect, pseudoelasticity and thermomechanical training in polycrystalline shape memory alloys. Acta Materialia 201 (2020) 580-595.

A phase-field model based on a modified form of the regularized formulation of Griffith’s fracture theory is presented to investigate intergranular and transgranular crack propagations in polycrystalline brittle materials. Grains and grain boundaries are incorporated in the crack initiation and propagation model based on a phase-field model for grain growth, in which the elastic anisotropy varies based on the grain orientation angle, and the grain boundary energy is related to the misorientation angle of the adjacent grains.

Open Access
A. Emdadi, J. Watts, W.G. Fahrenholtz, G.E. Hilmas, and M. Asle Zaeem. Predicting effective fracture toughness of ZrB2 based ultra-high temperature ceramics by phase-field modeling.  Materials & Design 192 (2020) 108713 (11 pages).

Thomas, M.S. Manju, K.M. Ajith, S.U. Lee and M. Asle Zaeem. Strain-induced work function in h-BN and BCN monolayers.  Physica E: Low-dimensional Systems andNanostructures 123 (2020) 114180 (9 pages).  

Abstract

C. Cissé and M. Asle Zaeem. A phase-field model for non-isothermal phase transformation and plasticity in polycrystalline yttria-stabilized tetragonal zirconia.  Acta Materialia 191 (2020) 111-123.