Publications de Seyed Masood Hafez Haghighat

Obstacle strength of binary junction due to dislocation dipole formation: An in-situ transmission electron microscopy study

We report the experimental observation of the 1/2 < 111 > edge dislocation dipole formation and annihilation in ultra-high purity Fe using transmission electron microscopy (TEM) in-situ straining. The observation is confirmed by TEM image simulations. The ...

Elsevier Science Bv2015

Atomistic simulation of the a(0) < 1 0 0 > binary junction formation and its unzipping in body-centered cubic iron

Seyed Masood Hafez Haghighat

Molecular dynamics simulation is used to study the formation of the a(0) < 1 0 0 > binary dislocation junction in body-centered cubic Fe. Results show that under an applied strain two intersecting 1/2 a(0) < 1 1 1 > dislocations, one mobile edge and one im ...

Pergamon-Elsevier Science Ltd2014

Molecular dynamics study of strengthening by nanometric void and Cr alloying in Fe

Seyed Masood Hafez Haghighat

Ferritic steels are the main candidates for the structural components of future fusion reactors. Because of the complexity of their structure, most of the simulation works are focused on the base phase of these materials such as alpha-Fe or Fe-Cr alloy. In ...

Elsevier Science Bv2013

In situ transmission electron microscopy of the interaction between a moving dislocation and obstacles of dislocation character in pure iron

Seyed Masood Hafez Haghighat

In this study, we report our observation of the interaction between a moving dislocation and an obstacle of dislocation character in pure bcc-Fe using a TEM in situ straining experiment at room temperature. Our observations reveal that the interaction of a ...

Taylor & Francis Ltd2013

Atomistic simulation of the influence of Cr on the mobility of the edge dislocation in Fe(Cr) alloys

Seyed Masood Hafez Haghighat

In this work Fe-Cr compounds, as model alloys for the ferritic base steels that are considered as main candidates for the structural materials of the future fusion reactors, are studied using molecular dynamics simulations. The Cr or so-called alpha' preci ...

Elsevier2011

Multiscale Modelling of Irradiation Induced Effects on the Plasticity of Fe and Fe-Cr

Seyed Masood Hafez Haghighat

Degradation of mechanical properties due to nanometric irradiation induced defects is one of the challenging issues in designing ferritic materials for future nuclear fusion reactors. Various types of defects, namely dislocation loops, voids, He bubbles an ...

EPFL2010

Strengthening due to Cr-rich precipitates in Fe–Cr alloys: Effect of temperature and precipitate composition

Robin Schäublin, Seyed Masood Hafez Haghighat

Molecular dynamics (MD) simulations were carried out to study the interaction between nanometric Cr precipitates and a 1/2 < 111 >>{110} edge dislocation (ED) in pure Fe and Fe-9 at. % Cr (Fe-9Cr) random alloy. The aim of this work is to estimate the vari ...

American Institute of Physics2010

Influence of the stress field due to pressurized nanometric He bubbles on the mobility of an edge dislocation in iron

Robin Schäublin, Seyed Masood Hafez Haghighat

Voids and He bubbles are strong obstacles to dislocation, which induce hardening and loss of ductility. In Fe, molecular dynamics simulation is used to investigate the basic mechanisms of the interaction between a moving edge dislocation and a void or He b ...

Taylor & Francis2010

State of a pressurized helium bubble in iron

Robin Schäublin, Seyed Masood Hafez Haghighat, Guillaume Lucas

We study the state of a nanometric helium bubble in bcc-iron as a function of temperature and He content using atomistic calculations. It appears that up to moderate temperatures the Fe lattice can conﬁne He to solid state, in good agreement with known sol ...

IOP Publishing - EPL Association2009

Dislocation-void interaction in Fe: a comparison between molecular dynamics and dislocation dynamics

Robin Schäublin, Seyed Masood Hafez Haghighat

Multiscale modeling, including molecular dynamics (MD) and discrete dislocation dynamics (DDD) methods, appears as a signiﬁcant tool for the description of plasticity and mechanical properties of materials. This research concerns the inﬂuence of irradiatio ...

2009

Atomistic simulation of He bubble in Fe as obstacle to dislocation

Robin Schäublin, Seyed Masood Hafez Haghighat, Guillaume Lucas

2009

Atomistic simulation of He bubble in Fe as obstacle to dislocation

Seyed Masood Hafez Haghighat, Guillaume Lucas

2008

Effect of interatomic potential on the behavior of dislocation-defect interaction simulation in α-Fe

Robin Schäublin, Seyed Masood Hafez Haghighat

Molecular dynamics simulation is one of the most useful methods to model defect generation and subsequent change in mechanical properties in material that will suffer irradiation in the future fusion reactors. This work is aimed at showing the influence of ...

2008

Investigation of limiting grain size and microstructure homogeneity in the presence of second phase particles using the Monte Carlo method

Seyed Masood Hafez Haghighat

2008

An analytical and experimental investigation on the normal grain growth in metals using the Monte Carlo method

Seyed Masood Hafez Haghighat

The prediction of material microstructure is of great interest to the material designers since the property and performance of materials depend strongly on their microstructures. In this work, a Monte Carlo approach is used to investigate the normal grain ...

2007

Molecular dynamics modeling of cavity strengthening in irradiated iron

Robin Schäublin, Seyed Masood Hafez Haghighat

One of the most important problems in the ﬁeld of nuclear industry is the relationship between irradiation-induced damage and the resulting induced mechanical response of the target metal and in particular ferritic base steels. In this work molecular dynam ...

2007

Effet de l'hélium sur le durcissement induit par irradiation dans le Fe

Robin Schäublin, Seyed Masood Hafez Haghighat

2006