The heart of crystalline materials

Materials are omnipresent in our daily lives. There are no structures or infrastructures that do not use materials. There can be no transportation or energy production without materials. Today they are called nanomaterials, architecture materials or even smart materials. They are fundamental to global economic activity and are also subject to special attention from academics, who are constantly improving, adapting and optimizing them to meet growing technological, environmental and societal demands.

The course, designed for engineering bachelor students, presents the fundamentals of the science of crystalline materials, favouring an angle firmly anchored at the crossroads of the three major scientific disciplines of chemistry, physics and mechanics. Created at the Institut Mines Télécom – Ecole Nationale Supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), it aims to introduce the main concepts of materials science and engineering that will prove useful to the generalist engineers that we train. It also contributes to the scientific foundation on which many courses dedicated to materials can be based and offered to our students later in their studies, particularly in the final year Major “Advanced Materials and Mechanical Engineering” and in the international master AeroMat-Innovation.

Divided into six chapters of varying length, the course introduces the concepts of architecture and cohesion of solids in Chapter 1, shows – as an example of the methods used for crystallographic characterization - how the crystalline material can be probed by ray diffraction (Chapter 2). Chapter 3 presents the difference between real and perfect crystals by identifying the defects present - classified according to their vectorial dimension - and their influence on the engineering properties. The formation and properties of metallic alloys as well as phase diagrams that govern thermodynamic equilibrium are then presented (Chapter 4). After detailing the basics of solid state diffusion processes, phase transformations, with and without diffusion are described in Chapter 5. Finally, Chapter 6, the longest, provides a detailed description of the behaviour of crystalline materials under static and dynamic stress and demonstrates how, by metallurgical, thermal or mechanical processing, materials properties can be improved.

Most of the micrographs, illustrations and videos contained in the document come from the author's own expertise and research work.