Keywords
Team
GEM - Genèse, Évolution des Microstructures
Biography
Mathias Lamari is a researcher specializing in the study of the mechanical and microstructural behavior of metallic materials, with particular expertise in advanced characterization and multiscale modeling. His work focuses in particular on the durability of thermal barrier coatings (TBCs), where he analyzes the interactions between oxidation, phase transformations, and mechanical stresses under cyclic thermal loading, using techniques such as high-energy X-ray diffraction (HEXRD). His approach combines in situ experiments and micromechanical modeling to elucidate degradation mechanisms, such as the plasticity of bonding layers or the formation of embrittling phases during carburization. At the same time, he is developing innovative models in crystalline plasticity, incorporating discrete parameters such as the plastic deformation threshold (Δpmin) to reproduce the intermittent nature of plastic flow at the microscopic scale, while remaining compatible with the continuous frameworks of continuum mechanics. His research also extends to advanced high-strength steels (AHSS), such as medium-manganese steels, where he studies the relationships between microstructure, residual austenite stability, and mechanical properties through the coupling of HEXRD, digital image correlation (DIC), and micromechanical modeling.
Publication(s)
-
2026
In Situ Investigation of Plasticity Mechanisms of the β Phase in (Ni, Pt)Al Bond Coats During Thermal Cycling by High-Energy X-Ray Diffraction DOI : 10.1007/s11661-025-08103-w
-
2025
A time-discontinuous elasto-plasticity formalism to simulate instantaneous plastic flow bursts DOI : 10.1016/j.ijsolstr.2024.113171
-
2025
Mechanical behavior study at the macroscopic and microscopic scales of carburized austenitic stainless steels using combined in-situ tensile test and high-energy X-ray diffraction DOI : 10.1016/j.msea.2025.149246
-
2024
SEM-WDS x STEM-EDS: Improving how we measure Mn partitioning in retained austenite in medium-Mn TRIP steels DOI : 10.1016/j.matchar.2024.113698
-
2024
Behavior of TRIP-aided medium Mn steels investigated by in situ synchrotron X-ray diffraction experiments and microstructure-based micromechanical modelling DOI : 10.1016/j.ijplas.2023.103866
-
2021
Recovery of severely deformed ferrite studied by in situ high energy X-ray diffraction DOI : 10.1016/j.matchar.2021.111378
-
2020
A physics-based mean-field model for ferrite recovery and recrystallization DOI : 10.3390/met10050622
-
2020
In situ determination of phase stress states in an unstable medium manganese duplex steel studied by high-energy X-ray diffraction DOI : 10.3390/met10101335
Teaching
Materials for Engineers
The in-person component (27 hours) is structured into plenary sessions in a lecture hall (12 hours), small-group sessions (12 hours) with smaller class sizes, and presentations of lab work before a panel (30 minutes). It also includes a written exam (2 hours and 30 minutes). Students’ independent work (18 hours) includes (in addition to the engine disassembly and reassembly activity mentioned above): A self-assessment multiple-choice quiz (30 min) on prerequisites. This self-assessment is conducted prior to the first class to identify students’ strengths and weaknesses and then focus on certain aspects during face-to-face instruction. An assignment on phase diagrams (2 hours) An assignment on material aging (2 hours) Practical lab work at the CMAT (6 hours): 13 lab sessions are conducted in groups of 4 to 5 students, supervised by the Center’s engineers and technicians as well as doctoral students, since most lab topics are related to current thesis projects. A 20-minute oral presentation for each lab is given at the end of the day in two parallel sessions. Students therefore complete one of the lab sessions and participate in or attend half of the presentations at the end of the day. Two similar days are organized to accommodate the entire class. Final exam review (5 hours)
PhD supervision
- 2026 The evolution of γ-γ' microstructures under thermomechanical fatigue conditions LAINÉ Etienne
- 2025 Effect of plastic deformation on cleavage fracture: decoupling between induced plasticity and microtexture evolution KA Rassoul
- 2025 Fatigue life prediction of a turbine disk alloy based on its microstructure L'HERMITE Tom