Concept

Hardening (metallurgy)

Publications associées (29)

Composition and Element Distribution Mapping of γ′ and γ" Phases of Inconel 718 by High-Resolution Scanning Transmission Electron Microscopy and X-ray Energy-Dispersive Spectrometry

The main strengthening mechanism for Inconel 718 (IN718), a Ni-based superalloy, is precipitation hardening by gamma ' and gamma '' particles. It is thus essential, for good alloy performance, that precipitates with the desired chemical composition have ad ...

MDPI2024

Dislocation Hardening in a New Manufacturing Route of Ferritic Oxide Dispersion-Strengthened Fe-14Cr Cladding Tube

Roland Logé

The microstructure evolution associated with the cold forming sequence of an Fe-14Cr-1W-0.3Ti-0.3Y2O3 grade ferritic stainless steel strengthened by dispersion of nano oxides (ODS) was investigated. The material, initially hot extruded at 1100 degrees C an ...

MDPI2024

Bringing casting to microfabrication: processing and deformation of microcastings

Luciano Borasi

This work extends the range of pathways for the production of metallic microcomponents by downscaling metal casting. This is accomplished by using either of two different molding techniques, namely femtosecond laser micromachining or lithographic silicon m ...

EPFL2023

Micro-addition of Fe in highly alloyed Cu-Ti alloys to improve both formability and strength

Roland Logé, Cyril Cayron, Baptiste Thomas Jean Rouxel

Cu-Be alloys provide excellent electrical and mechanical properties, but present serious health hazards during manufacturing. Among alternative alloys, the Cu-Ti system has the highest yield strength; however, Ti cannot be easily solutionized at concentrat ...

ELSEVIER SCI LTD2022

Development of High-Strength Aluminum Alloys for Additive Manufacturing

Marvin Lennard Schuster

Metal additive manufacturing (AM) offers the possibility to rapidly produce complex geometries that are not achievable with conventional manufacturing methods. The two most common technologies, Laser Powder Bed Fusion (LPBF) and Direct Metal Deposition (DM ...

EPFL2022

Screw vs. edge dislocation strengthening in body-centered-cubic high entrophy alloys and implications for guided alloy design

William Curtin, Francesco Maresca, Carolina Baruffi

Body-centered-cubic (BCC) high entropy alloys (HEAs) can show exceptionally high strength up to high temperatures. Mechanistic theories are needed to guide alloy discovery within the immense multicomponent HEA compositional space. Here, two new theories fo ...

SPRINGER HEIDELBERG2022

Giant hardening response in AlMgZn(Cu) alloys

William Curtin, Daniel John Gilles Marchand

This study presents a thermomechanical processing concept which is capable of exploiting the full industrial application potential of recently introduced AlMgZn(Cu) alloys. The beneficial linkage of alloy design and processing allows not only to satisfy th ...

PERGAMON-ELSEVIER SCIENCE LTD2021

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

APT/TEM characterization of the element segregation in ferritic/martensitic steels after irradiation in SINQ

Lijuan Cui

Ferritic /martensitic (FM) steels are among the most important materials in various nuclear applications. As radiation-induced segregation (RIS) is one of the major factors for embrittlement of nuclear materials, thereofre it is essential to study the RIS ...

EPFL2021

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

Mechanical properties of a balsa wood veneer structural sandwich core material

Thomas Keller, Anastasios Vassilopoulos, Niloufar Vahedi

Balsa wood is an appropriate core material for structural sandwich applications due to its high strength- and stiffness-to-weight ratios. However, the mechanical properties vary considerably owing to the inherent scattering of natural wood materials. One a ...

2020

Influence of thermo-mechanical processing on ordering kinetics in 18 karat red gold alloy

Marina Garcia Gonzalez

The aim of this project is to understand the correlation between alloy composition and the build-up of internal stresses in 18 carat Au-Ag-Cu alloys under thermo-mechanical loads. The copper rich end of this ternary system exhibits order-hardening of the e ...

EPFL2020

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

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

In situ characterization of work hardening and springback in grade 2 alpha-titanium under tensile load

Helena Van Swygenhoven

Plastic effects during sheet metal forming can lead to undesirable distortions in formed components. Here, the three-stage work hardening and plastic strain recovery ("springback") in a cold-rolled, alpha-phase commercially pure titanium is examined. Inter ...

2019

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

In Situ Deformation Studies of HCP Metal Alloys with Neutron Diffraction, X-Ray Diffraction, and High Resolution Digital Image Correlation

Karl Alan Sofinowski

Mg and Ti alloys are attractive materials for structural applications in the transportation and biomedical industries due to their high strength-to-weight ratios. However, due to their hexagonally close-packed (HCP) lattice structure, they exhibit poor for ...

EPFL2019

Monitoring of the UHPFRC strengthened Chillon viaduct under environmental and operational variability

Eugen Brühwiler

Constructed in 1969, the Chillon viaducts constitute a vital component of the Swiss roadway network. The bridge deck was strengthened in 2015 by means of an Ultra High Performance Fiber Reinforced Cement-based Composite for alleviating the effects of deter ...

2020

Solute/screw dislocation interaction energy parameter for strengthening in bcc dilute to high entropy alloys

William Curtin, Francesco Maresca, Alireza Ghafarollahi

Strengthening, i.e. increased stress required to move a dislocation, in dilute or complex alloys arises from the totality of the interaction energies between the solutes and an individual dislocation. Prevailing theories for strengthening in bcc alloys con ...

IOP PUBLISHING 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