Skip to Main content Skip to Navigation
Theses

Influence des conditions d’élaboration sur le comportement thermomécanique de phases MAX

Abstract : MAX phases are ternary carbide and/or nitride with a great potential in various application. This study concerned two MAX phase compounds, namely Ti3SiC2 and Ti2AlC, which are on the most studied among all known MAX phases. The first part dealt with materials elaboration which includes both synthesis and sintering stages. The objective was to obtain a variety of materials with different microstructural features, i.e. phase composition and grain size. For this purpose, both commercial and SHS-derived powders were densified with two pressure-assisted sintering technique, i.e. SPS and HP. The second part of work was devoted to deeper understanding of the influence of phase composition and grain size to thermomechanical behavior of MAX phases. More information was provided when two experimental techniques, four-point bending and AE monitoring, were coupled together with post-mortem SEM observations. The developed experimental approach based on comparison of mechanical responses of Ti3SiC2 (MAX phase and secondary phases) and Ti2AlC (containing only MAX phases) compounds, is implemented to investigate the induced deformation and damage mechanisms. It was shown that higher quantity of MAX phases in the material improves flexural strength with corresponding more pronounce nonlinear behavior and high dissipated energy. When MAX phase grains are coarser the mechanical strength lowers but the nonlinear part becomes more significative, which results in higher values of dissipated energy. It was also shown that the secondary phases and the grain size impact the way in which the damage is accumulated within the sample. AE data provided more information on possible damage mechanisms and their chronology leading to hysteretic behavior of MAX phases. The last part has shown that the BPTT for Ti3SiC2 is ≈1200˚C and the grain size of MAX phases lowers this BPTT.
Document type :
Theses
Complete list of metadatas

Cited literature [156 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02361687
Contributor : Abes Star :  Contact
Submitted on : Wednesday, November 13, 2019 - 2:55:29 PM
Last modification on : Thursday, November 14, 2019 - 1:25:41 AM
Long-term archiving on: : Friday, February 14, 2020 - 4:30:13 PM

File

2019LIMO0047.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02361687, version 1

Collections

Citation

Karolina Kozak. Influence des conditions d’élaboration sur le comportement thermomécanique de phases MAX. Matériaux. Université de Limoges; AGH University of Science and Technology (Cracovie, Pologne), 2019. Français. ⟨NNT : 2019LIMO0047⟩. ⟨tel-02361687⟩

Share

Metrics

Record views

220

Files downloads

57