Publications associées à Acier à outils

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

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

Thermal Modelling and Experimental Validation in the Perspective of Tool Steel Laser Polishing

Eric Boillat, Alexandre Masserey, Bastian Meylan

Laser polishing (LP) is a process that allows a significant reduction of the surface roughness of a metal workpiece via re-melting a shallow layer of material. However, the practical use of LP is limited due to the difficulty of satisfying the high surface ...

MDPI2022

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

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

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

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

Roland Logé, Cyril Cayron, 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

Diffraction artefacts from twins and stacking faults, and the mirage of hexagonal, polytypes or other superstructures

Cyril Cayron

Recently, a hexagonal phase has been reported in high carbon steels in several studies. Here, we show that the electron microscopy results used in these studies were erroneously interpreted. The extra-spots in the diffraction patterns and the odd contrasts ...

2020

Multiaxial fatigue analysis of high-strength steel welded joints using generalized local approaches

Martin Antonio René Garcia

The objective of this thesis is to improve methods for predicting the fatigue life, multiaxial or not, of mild- and more particularly high-strength steels using local approaches that have the capacity to be applicable to almost any cases, hence the term ge ...

EPFL2020

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

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

Mechanical properties of MC multimetallic carbides in steel

Lionel Michelet

Carbides constitute a class of materials used for many applications, where excellent mechanical properties, such as stiffness, hardness and fracture toughness, are required. The machining industry is a typical example where carbide are crucial materials. W ...

EPFL2018

A new hybrid Additive Manufacturing process combining Selective Laser Melting and Laser Shock Peening

Nikola Kalentics

Additive Manufacturing (AM) in whole and especially Selective Laser Melting (SLM) are already making a revolution in the way parts are designed and manufactured with the ability to produce lightweight parts with unprecedented complex geometries which are o ...

EPFL2018

Optimisation of Current and Pulse Duration in Electric Discharge Drilling of D2 Steel Using Graphite Electrode

Electric discharge machining (EDM) is one of the viable techniques for machining of D2 steel, in which the material removal occurs by spark erosion. The poor selection of EDM parameters affect the machining quality and productivity. Considering this, the p ...

2018

Improving the collapse risk of steel structures with high-performance steel

Dimitrios Lignos

With the advent of material science, high-performance steel materials have been developed for seismic applications that potentially reduce the earthquake-induced collapse risk of steel frame buildings. The High Yield Point (HYP400) steel is one of those ma ...

2018

Numerical simulation of the probability of corrosion initiation of RC elements made of reinforcing steel with improved corrosion performance

Eugen Brühwiler, David Conciatori

Steel reinforcing bars in concrete are protected from corrosion by a thin oxide film that is created on the steel surface in the highly alkaline environment of the concrete. Corrosion process begins once this oxide film is destroyed, for example, by chlori ...

2018

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

William Curtin, Céline Varvenne, Joël Bonneville

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

Influence of geometrical imperfections and flaws at welds of steel liners on fatigue behavior of pressure tunnels and shafts in anisotropic rock

Alexandre Jean Pachoud

The recent development of high-strength (HSS) weldable steels has enlarged the range of design alternatives for the optimization of high-head steel-lined pressure tunnels and shafts (SLPT&S) in the hydropower industry. With the liberalization of the Europe ...

EPFL2017

Ultra low cycle fatigue of welded steel joints under multiaxial loading

Albano António De Abreu E Presa De Castro E Sousa

Extreme loading scenarios such as earthquakes, exceptional wind gusts or tides are characterized by very high amplitude and multidirectional cyclic loads applied to a structure. Ultra Low Cycle Fatigue (ULCF) arises in such cases and can be summarily defin ...

EPFL2017