Publication

Influence of Minor Additions on Icosahedral Short-Range Order (ISRO) and Its Consequences on Nucleation and Solidification Growth Kinetics in fcc Alloys

Publications associées (30)

Solidification of Metallic Alloys: Does the Structure of the Liquid Matter?

In 1952, Frank (Proc R Soc Lond Ser-Math Phys Sci 215:43-46, 1952) already postulated that Icosahedral Short Range Order (ISRO) of atoms in the liquid could possibly explain the large nucleation undercoolings measured in metallic alloys by Turnbull and Fis ...

SPRINGER2020

Additive Manufacturing of L12 Precipitate Strengthened Nickel and Aluminum Alloys

Seth James Griffiths

Metal Additive Manufacturing (AM) technologies have enabled the manufacturing of parts with complex geometries that were previously not feasible with conventional manufacturing. Unfortunately, many commercial engineering alloys (with the exception of alloy ...

EPFL2020

Solute-dislocation interactions and creep-enhanced Cu precipitation in a novel ferritic-martensitic steel

Cyril Cayron, Roland Logé, Bo Xiao

G115 steel has gained a growing interesting recently for its use in next-generation ultra-supercritical power plant applications. Due to the high densities of dislocations and lath martensite boundaries in G115 steel, interactions between solutes and dislo ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Combining alloy and process modification for micro-crack mitigation in an additively manufactured Ni-base superalloy

Jamasp Jhabvala, Christian Leinenbach, Roland Logé, Xavier Maeder, Hossein Ghasemi Tabasi, Toni Ivas, Rafal Wróbel

The additive manufacturing (AM) of the gamma' precipitation strengthened Ni-base superalloys still remains a challenge due to their susceptibility to micro-cracking. Post-processing, such as HIPing, has been shown to heal the micro-cracks but it remains de ...

ELSEVIER2020

Grain morphology reconstruction of crystalline materials from Laue three-dimensional neutron diffraction tomography

Stavros Samothrakitis, Marina Garcia Gonzalez, Markus Strobl

The macroscopic properties of advanced engineering and functional materials are highly dependent on their overall grain orientation distribution, size, and morphology. Here we present Laue 3D neutron diffraction tomography providing reconstructions of the ...

Nature Research2020

Concurrent multiscale modeling and theory of solute-strengthening for dilute and complex concentrated alloys

Shankha Nag

Under common processing conditions, both dilute and complex concentrated alloys are often realized as random alloys, with no correlation in the occupancy of lattice sites by the constituent atom types. The current thesis primary addresses two problems in r ...

EPFL2020

Theory of screw dislocation strengthening in random BCC alloys from dilute to "High-Entropy" alloys

William Curtin, Francesco Maresca

Random body-centered-cubic (BCC) "High Entropy" alloys are a new class of alloys, some having high strength and good ductility at room temperature and some having exceptional high-temperature strength. There are no theories of strengthening of screw disloc ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Solute-strengthening in elastically anisotropic fcc alloys

William Curtin, Céline Varvenne, Shankha Nag

Dislocation motion through a random alloy is impeded by its interactions with the compositional fluctuations intrinsic to the alloy, leading to strengthening. A recent theory predicts the strengthening as a function of the solute-dislocation interaction en ...

IOP PUBLISHING LTD2020

Mechanistic origin of high strength in refractory BCC high entropy alloys up to 1900K

William Curtin, Francesco Maresca

The body centered cubic (BCC) high entropy alloys (HEAs) MoNbTaW and MoNbTaVW show exceptional strength retention up to 1900K. The mechanistic origin of the retained strength is unknown yet is crucial for finding the best alloys across the immense space of ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Theory of double-kink nucleation in dilute BCC alloys

William Curtin, Alireza Ghafarollahi

Yielding in pure BCC metals and dilute substitutional alloys occurs by double-kink nucleation and propagation along screw dislocations. At low temperatures, the yield stress is controlled by double-kink nucleation. Here, an analytical statistical model is ...

PERGAMON-ELSEVIER SCIENCE LTD2020