Publications related to Austenite

Phase Transformation-Induced Interfacial Debonding of Silica Inclusions in Iron

Andreas Mortensen, David Hernandez Escobar, Julie Nathalie S Gheysen, Alejandra Inés Slagter

We document that in unstressed, undeformed, samples of pure iron containing silica inclusions precipitated by melt deoxidation, the iron matrix and a small fraction of the silica inclusions are locally separated at room temperature by a void. Thermal cycli ...

Springer2023

Origin of the enhanced pseudo-elasticity of additively manufactured Fe-17Mn-5Si-4Ni-10Cr-(V, C) shape memory alloy fabricated by laser powder bed fusion

Christian Leinenbach, Irene Ferretto

This study investigated the origin of the enhanced pseudo-elasticity of additively manufactured vanadium carbide-containing Fe-based shape memory alloys. The aged samples with two different starting microstructures, as-built and solution-treated, showed co ...

Elsevier Science Sa2023

Effect of post-heat treatment conditions on shape memory property in 4D printed Fe-17Mn-5Si-10Cr-4Ni shape memory alloy

Christian Leinenbach, Irene Ferretto

The influence of post-heat treatment on the microstructure and properties of 4D printed Fe-17Mn-5Si-10Cr-4Ni (wt. %) shape memory alloy (SMA) produced via a laser powder bed fusion process is investigated in this study. It is shown that heat-treatment temp ...

2022

Non-Linear Behaviors In The Dynamics Of Complex Systems Through A Multifractal Hydrodynamic Model

Maria-Alexandra Paun

Some non-linear behaviors in the dynamics of complex systems using the Scale Relativity Theory in the form of Multifractal Hydrodynamic Model are analyzed. By assimilating any complex system to a mathematical multifractal-type object, it is shown that the ...

UNIV POLITEHNICA BUCHAREST, SCI BULL2022

Highly Ordered and Thermally Stable FeRh Cluster Superlattice on Graphene for Low-Temperature Catalytic CO Oxidation

Harald Brune, Jean-Guillaume De Groot, Hao Yin

We report on bimetallic FeRh clusters with a narrow size-distribution grown on graphene on Ir(111) as a carbon-supported model catalyst to promote low-temperature catalytic CO oxidation. By combining scanning tunneling microscopy with catalytic performance ...

WILEY-V C H VERLAG GMBH2022

Characterization of untransformed ferrite in 10Cr and 12Cr ODS steels

Roland Logé

Two new ferrito-martensitic oxide dispersion strengthened (ODS) steels reinforced with (Y, Ti, O) nanoparticles were elaborated using a high-energy attritor. The milled powder was consolidated by hot extrusion at 1050 degrees C. The two types of ODS steels ...

ELSEVIER SCI LTD2021

Microstructural Evolution Study of Fe-Mn-Al-C Steels Through Variable Thermomechanical Treatments

Roland Logé, Oscar Zambrano Zambrano

The microstructural evolution of the two austenitic alloys Fe-20Mn-3Al-0.7C wt pct and Fe-20Mn-6Al-0.7C wt pct when different thermal and thermomechanical treatments are performed has been studied. To this end, a generic industrial die of 100 ton capacity ...

SPRINGER2021

The effect of stress triaxiality on the phase transformation in transformation induced plasticity steels: Experimental investigation and modelling the transformation kinetics

Helena Van Swygenhoven, Nicola Casati, Efthymios Polatidis

In situ multiaxial loading during neutron diffraction tests were undertaken on a low-alloyed Quenched and Partitioning (Q&P) Transformation Induced Plasticity (TRIP) Bainitic Ferrite (TBF) steel with dispersed austenite particles. The effect of stress tria ...

2021

Crystallization kinetics of atomic crystals revealed by a single-shot and single-particle X-ray diffraction experiment

Christoph Bostedt, Alessandro Colombo, Giorgio Rossi

Crystallization is a fundamental natural phenomenon and the ubiquitous physical process in materials science for the design of new materials. So far, experimental observations of the structural dynamics in crystallization have been mostly restricted to slo ...

National Academy of Sciences2021

Laser powder-bed fusion of metallic alloys with enhanced microstructures and properties

Navid Sohrabi

Laser powder-bed fusion (LPBF) is an additive manufacturing (AM) process that uses a laser to selectively melt a powder bed. This process can build dense samples with complicated geometries from a wide variety of metallic alloys. In this thesis, LPBF of al ...

EPFL2021

Deformation mechanisms in a superelastic NiTi alloy: An in-situ high resolution digital image correlation study

Helena Van Swygenhoven, Efthymios Polatidis

An in-situ high resolution digital image correlation investigation during uniaxial tensile deformation reveals the recoverable and the non-recoverable strain mechanisms in a Ni51Ti49 alloy with a mean grain size of 35 mu m. Recoverable strain is due to the ...

2020

First principles study of the effect of hydrogen in austenitic stainless steels and high entropy alloys

William Curtin, Xiao Zhou

Hydrogen (H) embrittlement in multicomponent austenitic alloys is a serious limitation to their application in many environments. Recent experiments show that the High-Entropy Alloy (HEA) CoCrFeMnNi absorbs more H than 304 Stainless Steel but is less prone ...

2020

A New Reference for the Thermal Equation of State of Iron

James Badro

The high-pressure, high-temperature behavior of iron was investigated to 140 GPa and 3500 K with in situ synchrotron X-ray diffraction. Iron samples were compressed in diamond-anvil cells and heated up with the double-sided laser-heating system installed a ...

MDPI2020

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

Michel Rappaz, Güven Kurtuldu

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

Operando X-ray diffraction during laser 3D printing: from machine design to experiments and computer simulations

Samy Hocine

The importance of additive manufacturing, also known as 3D printing, has grown exponentially in the recent years thanks to its high flexibility to manufacture intricate parts. This process can be divided into many different sub-categories, depending on the ...

EPFL2020

Thermal coarsening of individual titanate nanowires and their assemblies: Surface vs. bulk diffusion

László Forró, Luca Rossi, Endre Horvath, Sergiy Katrych, Massimo Spina, Laurent Syavoch Bernard, Xavier Berdat

The thermal coarsening of titanate nanowires was investigated from room temperature to 1000 degrees C by AFM, SEM, XRD and Raman spectroscopy. Phase transformation kinetics and the external morphology were studied in two configurations: i) as individual an ...

2020

A crystallographic extension to the Olson-Cohen model for predicting strain path dependence of martensitic transformation

Helena Van Swygenhoven, Efthymios Polatidis

A modification to the empirical Olson-Cohen strain-induced austenite to martensite transformation kinetic model is proposed. The proposed kinetic model accounts for the stress state at the grain level and the crystallography of the transformation mechanism ...

PERGAMON-ELSEVIER SCIENCE LTD2019

The interplay between deformation mechanisms in austenitic 304 steel during uniaxial and equibiaxial loading

Helena Van Swygenhoven, Efthymios Polatidis, Wei-Neng Hsu

The preferred deformation mechanisms with respect to the load path are studied in a medium stacking fault energy 304 austenitic stainless steel that exhibits both transformation induced plasticity and twinning induced plasticity. In situ neutron diffractio ...

2019

In situ characterization of a high work hardening Ti-6Al-4V prepared by electron beam melting

Helena Van Swygenhoven, Karl Alan Sofinowski, Nicola Casati

A multi-phase Ti-6Al-4V prepared by electron beam melting and thermal post treatments has been shown to exhibit increased strength and ductility over standard wrought or hot isostatic pressed Ti-6-Al-4V. The mechanical improvements are due to a prolonged, ...

2019

On the chevron morphology of surface martensite

Roland Logé, Cyril Cayron, Annick Pauline Baur

It is established that the annealing twin boundaries of austenite act as nucleation sites for the martensitic transformation. In the present study, we observe that in surface martensite the transformation only takes place for twin boundaries that are appro ...

2019