SC3 Louisette Priester

Short Course on
“Interfaces in Crystalline Materials”

by Louisette PRIESTER

      Grain boundaries (homophase interfaces) and interphase interfaces are major elements of the microstructures of crystalline materials. They play an important role in the material properties: corrosion, wetting, mechanical and electrical properties…, particularly when the grain size decreases. Recently, new manufacturing processes allow us to manage the quantity and the diversity of the interfaces in a polycrystal in order to obtain some special behaviors. But the first step to go toward this “interface engineering” rests on the knowledge of the interface structures that differ according to interface geometry and chemistry; also very important are the interface defects responsible of most practical properties.

            The course will give basic notions about interface structures, with a focus on grain boundaries. (Examples concern metals, ceramics or semi-conductors). Then, it will describe the interface defects, particularly dislocations: their origin, their characteristics, their interactions with the crystal defects and the consequences for material plasticity and rupture. The important role of the interface chemistry will be approached via two phenomena: segregation and precipitation, together with their influence on the fine grain boundary structures. Finally, some examples of interface distributions in polycrystals (essentially grain boundary character distributions) are related; such macroscopic information constitutes the necessary step to understand the role of the grain boundary network in properties of the whole material.  

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10:00 – 10:30 Registration
10:30 – 11:30 Session 1. Basics. Grain boundary and interphase interface geometry – bicrystallography -Stress distribution in grain boundaries: intergranular intrinsic dislocations – Atomic structures of grain boundaries – Relation between atomic structures and dislocations intergranular energy. Grain boundary and interface classifications.  
11:30 – 11:45 Coffee break  
11:45 – 12:45 Session 2. Grain boundary defects. - Origin and description of different types of grain boundarydefects:punctual defects (solutes in grain boundaries), linear defects (extrinsic dislocations) and volume defects (precipitates) – Relation between the grain boundary structure and the defect characteristics  
12:45 – 14:00 Lunch break (lunch not included)  
14:00 – 15:00 Session 3. Interaction between grain boundary and other crystalline defects. Absorption or transmission of dislocations by grain boundaries – Stress relaxation in grain boundaries interaction with punctual defects (segregation phenomenon)  
15:00 – 15:15 Coffee break  
15:15 – 16:15 Session 4. Grain boundary properties and role in material behaviors. – Various individual grain boundary properties: corrosion, wetting, plasticity, rupture…Grain boundary ensemble in polycrystals – Some consequences on material properties.  
   

Handouts

Copies of all slides in the PowerPoint format will be provided at the beginning of the SC. Copy of the course slides may be also reported on a memory stick

 

Speaker

Louisette Priester is professor emeritus of University Paris South 11; she taught Material Sciences for several years at different level and, particularly, for Graduate students. She was responsible of a master in Material Sciences that prepares to thesis. She also taught at Stony Brook University.

            As researcher, she was responsible of a team entitled “Grain Boundaries: structure, defects and properties“. She particularly works on grain boundary defects (in metals and ceramics) and on the interactions between grain boundaries and crystal defects, with a special focus on the consequences on the mechanical properties of the material.

            She had several invited conferences in international meetings; she served as visiting professor at different places all along her carrier: MIT (Boston USA), Ohio State University (Columbus, USA), Institute of Industrial Sciences (Tokyo, Japan), Mechanical and Materials Science Laboratory (Kyoto, Japan), Laboratory for nanostructured materials and low dimensional physics (Beida University, Beijing, China).  She wrote two books in French; one deals with her research domain: “Grain Boundaries: from Theory to Engineering” (published by EDP Sciences in 2006); the other one is more general, devoted to popularization of the knowledge: “Materials: History, Science and perspectives“(published by CNRS Editions in 2008).