Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Dislocation Movement and Recrystallization

In course

MSE-310: Deformation of materials

Présentation des mécanismes de déformation des matériaux inorganiques: élasticité, plasticité, fluage. ...

Description

This lecture explores the movement of dislocations under different constraints, the impact of obstacles on dislocation motion, and the role of solute atoms in influencing dislocation behavior. It also delves into the process of recrystallization, discussing the factors affecting grain growth and the influence of second-phase particles. The instructor discusses the energy associated with grain boundaries and sub-joints, as well as the kinetics of recrystallization. Various phenomena such as joint anchoring by precipitates and the effect of particles on recrystallization speed are also covered.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Instructor

Roland Logé

Roland Logé is an associate professor at EPFL, with a primary affiliation to the Materials Institute, and a secondary affiliation to the Microengineering Institute. After graduating in 1994 at UCL (Belgium) in Materials Engineering, he earned a Master of Science in Mechanics in 1995, at UCSB Santa Barbara (USA). He received his PhD at Mines Paristech-CEMEF (France) in 1999, where he specialized in metal forming and associated microstructure evolutions. After a postdoc at Cornell University (USA) between 1999 and 2001, he entered CNRS in France. In 2008, he was awarded the ALCAN prize from the French Academy of Sciences, together with Yvan Chastel. In 2009 he became head of the Metallurgy-Structure-Rheology research group at CEMEF. In 2011, he launched a “Groupement de Recherche” (GDR), funded by CNRS, networking most of the researchers in France involved in recrystallization and grain growth. In 2013, he became Research Director at CNRS. In March 2014 he joined EPFL as the head of the Laboratory of Thermomechanical Metallurgy.

Official source

Ontological neighbourhood

Chemical engineering

Materials science: Deformation of materials

Related concepts (32)

Grain boundary

In materials science, a grain boundary is the interface between two grains, or crystallites, in a polycrystalline material. Grain boundaries are two-dimensional defects in the crystal structure, and tend to decrease the electrical and thermal conductivity of the material. Most grain boundaries are preferred sites for the onset of corrosion and for the precipitation of new phases from the solid. They are also important to many of the mechanisms of creep.

Recrystallization (metallurgy)

In materials science, recrystallization is a process by which deformed grains are replaced by a new set of defect-free grains that nucleate and grow until the original grains have been entirely consumed. Recrystallization is usually accompanied by a reduction in the strength and hardness of a material and a simultaneous increase in the ductility. Thus, the process may be introduced as a deliberate step in metals processing or may be an undesirable byproduct of another processing step.

Abnormal grain growth

Abnormal or discontinuous grain growth, also referred to as exaggerated or secondary recrystallisation grain growth, is a grain growth phenomenon through which certain energetically favorable grains (crystallites) grow rapidly in a matrix of finer grains resulting in a bimodal grain size distribution. In ceramic materials this phenomenon can result in the formation of elongated prismatic, acicular (needle-like) grains in a densified matrix with implications for improved fracture toughness through the impedance of crack propagation.

Grain growth

In materials science, grain growth is the increase in size of grains (crystallites) in a material at high temperature. This occurs when recovery and recrystallisation are complete and further reduction in the internal energy can only be achieved by reducing the total area of grain boundary. The term is commonly used in metallurgy but is also used in reference to ceramics and minerals. The behaviors of grain growth is analogous to the coarsening behaviors of grains, which implied that both of grain growth and coarsening may be dominated by the same physical mechanism.

Crystallite

A crystallite is a small or even microscopic crystal which forms, for example, during the cooling of many materials. Crystallites are also referred to as grains. Bacillite is a type of crystallite. It is rodlike with parallel longulites. The orientation of crystallites can be random with no preferred direction, called random texture, or directed, possibly due to growth and processing conditions.

Related lectures (31)

A Random Walk Through Random Materials

Explores random materials, solutes, and their impact on mechanical performance, including strength, toughness, and fatigue.

Mechanisms of Metal Plasticity

Explores metal plasticity mechanisms, including hardening by solid solution and precipitation, dislocation forests, and polymer behavior in relation to temperature and deformation speed.

Materials Properties: Ductility, Hardness, Toughness

Explores materials' ductility, hardness, and toughness, covering dislocations, hardening mechanisms, and polymer behavior.

Plastic Deformation: Introduction to the Dislocation Model

Covers plastic deformation, dislocation model, stages, shear stress, distortion, dislocation loops, strain hardening, and crystal growth.

Plasticity: Mechanisms of Metals and Polymers