Publications by Ludger Weber | EPFL Graph Search

Liquid metal infiltration of silicon based alloys into porous carbonaceous materials Part-III: Experimental verification of conversion products and infiltration depth by infiltration of Si-Zr alloy into mixed SiC/ graphite preforms

Ludger Weber, Annapaola Parrilli, Caroline Hain, Alberto Ortona, Manoj Kondibhau Naikade

Porous carbonaceous preforms, made from graphite and silicon carbide (SiC) powders, with varying graphite powder mass fractions and particle sizes, were infiltrated at 1500 degrees C and 1700 degrees C by Si-8 at. pct Zr alloy to produce dense Si-Zr-SiC co ...

ELSEVIER SCI LTD2023

Liquid metal infiltration of silicon based alloys into porous carbonaceous materials. Part I: Modelling of channel filling and reaction phase formation

Ludger Weber, Alberto Ortona, Manoj Kondibhau Naikade

A relation for an adequate pore fraction needed to obtain residual Si and C free composites via reactive Si-X alloy infiltration is presented. The volume ratio of SiC and carbonaceous phase, the composition of the infiltrating liquid and the apparent densi ...

ELSEVIER SCI LTD2022

Liquid metal infiltration of silicon based alloys into porous carbonaceous materials. Part II: Experimental verification of modelling approaches by infiltration of Si-Zr alloy into idealized microchannels

Ludger Weber, Caroline Hain, Giovanni Bianchi, Alberto Ortona, Manoj Kondibhau Naikade

In this work, the mechanisms leading to the pore closure in reactive melt infiltration (RMI) of carbon by pure silicon and a near eutectic Si-8 at-pct Zr alloy at 1500 and 1700 degrees C under vacuum were studied. Various geometrical configurations of micr ...

ELSEVIER SCI LTD2022

A quantum magnetic analogue to the critical point of water

Henrik Moodysson Rønnow, Frédéric Mila, Bruce Normand, Christian Rüegg, Ludger Weber, Ellen Fogh, Mohamed Zayed, Julio Antonio Larrea Jiménez, Kazimierz Conder

At the liquid-gas phase transition in water, the density has a discontinuity at atmospheric pressure; however, the line of these first-order transitions defined by increasing the applied pressure terminates at the critical point(1), a concept ubiquitous in ...

2021

Kinetic processes in the high-temperature pressure-infiltration of Al into Al2O3

Andreas Mortensen, Ludger Weber, Marta Fornabaio, Gionata Schneider

We explore the influence (i) of the interaction between aluminium and alumina, and (ii) of sodium impurities present in Bayer alumina, on the pressure infiltration of alumina particle preforms with molten aluminium. At 1000°C or above, although the alumini ...

2020

Mechanical properties and cytocompatibility of dense and porous Zn produced by laser powder bed fusion for biodegradable implant applications

Andreas Mortensen, Ludger Weber, Karel Lietaert

In this work, the macrotexture of dense Zn produced by laser powder bed fusion (LPBF) was studied and the mechanical properties for different tensile bar orientations were measured. The compressive strength of LPBF Zn scaffolds with five different unit cel ...

ELSEVIER SCI LTD2020

Role of the electron-phonon coupling on the thermal boundary conductance of metal/diamond interfaces with nanometric interlayers

Ludger Weber, Maïté Blank, Gionata Schneider

Thermal boundary conductance (TBC) of the Ag/diamond and Au/diamond interfaces with a nanometer-thick interface layer of either nickel or molybdenum is measured by time domain thermoreflectance and modeled based on a 3-layer two-temperature model (3l-TTM). ...

2019

Studying the wettability of Si and eutectic Si-Zr alloy on carbon and silicon carbide by sessile drop experiments

Ludger Weber, Alberto Ortona, Manoj Kondibhau Naikade

The contact angles of two different systems, molten silicon and a eutectic Si-8 at. pct Zr alloy and their evolution over timeon vitreous carbon and polycrystalline silicon carbide (SiC) substrates were investigated at 1500 degrees C under vacuum, as well ...

ELSEVIER SCI LTD2019

Towards a coherent database of thermal boundary conductance at metal/dielectric interfaces

Ludger Weber, Maïté Blank

The thermal boundary conductance (TBC) of metal/dielectric couples was measured for a large variety of metals on silicon, sapphire, and diamond using time domain thermoreflectance and compared to data previously obtained on diamond. In the case of silicon, ...

2019

Influence of interfacial structural disorder and/or chemical interdiffusion on thermal boundary conductance for Ti/Si and Au/Si couples

Ludger Weber, Maïté Blank

This work aims at experimentally assessing the effect of structural disorder and/or chemical interdiffusion on thermal boundary conductance (TBC) at metal/dielectric interfaces. To this end, the TBC of Au/Si and Ti/Si interfaces was measured by time domain ...

2019