Publications de Céline Varvenne

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

Combining experiments and modeling to explore the solid solution strengthening of high and medium entropy alloys

William Curtin, Céline Varvenne

The mechanical properties due to solid solution strengthening are explored within the single phase face-centered cubic (fcc) domain of the Co-Cr-Fe-Mn Ni high entropy alloy (HEA) system. This is achieved by combining an efficient and reproducible metallurg ...

2019

Thermal activation parameters of plastic flow reveal deformation mechanisms in the CrMnFeCoNi high-entropy alloy

Joël Bonneville, William Curtin, Céline Varvenne

To reveal the operating mechanisms of plastic deformation in an FCC high-entropy alloy, the activation volumes in CrMnFeCoNi have been measured as a function of plastic strain and temperature between 77 K and 423 K using repeated load relaxation experiment ...

2018

Predicting yield strengths of noble metal high entropy alloys

William Curtin, Céline Varvenne

Recent data on the Noble metal (Pd-Pt-Rh-Ir-Au-Ag-Cu-Ni) high entropy alloys (HEAs) shows some of these materials to have impressive mechanical properties. Here, a mechanistic theory for the temperature-, composition-, and strain-rate-dependence of the ini ...

2018

Atomistic simulations of dislocations in a model BCC multicomponent concentrated solid solution alloy

William Curtin, Céline Varvenne, Satish I Rao

Molecular statics and molecular dynamics simulations are presented for the structure and glide motion of a/2(111) dislocations in a randomly-distributed model-BCC Co16.67Fe36.67Ni16.67Ti30 alloy. Core structure variations along an individual dislocation li ...

Elsevier2017

Strengthening of high entropy alloys by dilute solute additions: CoCrFeNiAlx and CoCrFeNiMnAlx alloys

William Curtin, Céline Varvenne

A theory to predict the initial flow stress of an arbitrary N-component fcc random alloy is extended to predict the additional strengthening when a dilute concentration of a substitutional element is introduced. Assuming properties for the N-component allo ...

2017

Solute strengthening in random alloys

William Curtin, Céline Varvenne, Maryam Ghazisaeidi

Random solid solution alloys are a broad class of materials that are used across the entire spectrum of engineering metals, whether as stand-alone materials (e.g. Al-57xxx alloys) or as the matrix in precipitate strengthening materials (e.g. Ni-based super ...

Elsevier2017

Average-atom interatomic potential for random alloys

William Curtin, Céline Varvenne

An average-atom (A-atom) embedded-atom-method potential for random multicomponent alloys at any composition is derived analytically and validated by comparing A-atom and true random alloys bulk and defect properties, in model Fe-Ni-Cr systems. The A-atom c ...

Amer Physical Soc2016

Theory of strengthening in fcc high entropy alloys

William Curtin, Céline Varvenne

High Entropy Alloys (HEAs) are a new class of random alloys having impressive strength and toughness. Here, a mechanistic, parameter-free, and predictive theory for the temperature-, composition-, and strain-rate-dependence of the plastic yield strength of ...

Pergamon-Elsevier Science Ltd2016

Theory of strengthening in fcc high entropy alloys (vol 118, pg 164, 2016)

William Curtin, Céline Varvenne

Elsevier2016

Pressure, relaxation volume, and elastic interactions in charged simulation cells

Céline Varvenne

The ab initio calculation of charged supercells within density-functional theory is a necessary step to access several important properties of matter. The relaxation volume of charged point defects or the partial molar volume of ions in solution are two su ...

Amer Physical Soc2015