Séminaires > In-situ TEM nanomechanical testing : Plasticity under the (electron) spotlight
Date : 26 mars 14h
Lieu : Salle Barthélémy
Abstract :
Recently, the development of a new generation of advanced instruments for in-situ nanomechanical testing inside the transmission electron microscope (TEM) has allowed establishing a one-to-one relationship between load-displacement characteristics and stress-induced microstructure evolution in the transmission electron microscope. In the present work, it will be demonstrated that a step forward in the investigation of the small-scale plasticity mechanisms in crystalline and amorphous materials can be made by combining commercial and in-house developed lab-on-chip micro/nanomechanical testing techniques with advanced TEM techniques including high resolution aberration corrected (S)TEM and spectroscopy, Angstrom-beam-electron-diffraction as well as automated crystallographic orientation, phase and nanostrain mapping in TEM. These techniques have been used to reveal the fundamental plasticity mechanisms activated in freestanding nanocrystalline and metallic glass thin films and, more recently, advanced hybrid nanolaminated materials combining metallic and amorphous oxide layers as well as the minerals of the upper mantle.
Bio :
Pr. Hosni IDRISSI is the head of the materials and process engineering (IMAP) division of the Institute of Mechanics, Materials, and Civil Engineering (iMMC) at UCLouvain in Belgium. IMAP is composed of 7 faculty members and about 100 researchers. He obtained his PhD in materials science at UMarseille Aix-III (France) in 2006. Following 2 years of postdoctoral research at INSA de Lyon and ULille in France and 8 years as senior researcher at UAntwerp and UCLouvain, he joined the iMMC Institute at UCLouvain as FNRS research associate and Professor in 2016, where he established a new activity focusing on the investigation of the elementary mechanisms controlling the processing and deformation of inorganic materials using electron microscopy. This activity involves a strong long-term collaboration between UCLouvain and the EMAT laboratory in UAntwerp. The focus is put on crystalline materials with micro-nanostructures dominated by internal interfaces such as nanocrystalline metallic thin films and advanced steels and alloys exhibiting twins, phase and antiphase boundaries, nanoprecipitates and nanocracks. Recently, the attention has been partly shifted towards amorphous oxides and metallic glass materials, the minerals of the Earth’s mantle as well as the impact of mechanical strain on different solid-state physics phenomena including chemical, electrical, thermal and irradiation couplings.