Skip to Main content Skip to Navigation
Theses

Allumage, combustion et explosion des poudres d'aluminium, de titane et de leurs alliages

Abstract : In recent years, the layer-by-layer manufacturing process seems to be used increasingly amongst the aeronautics, space or defense industries. These Additive Layer Manufacturing processes use metal powders from metallurgical alloys commonly used in the mechanical industry. The EXPAALT project was developed on the problematic of explosion risk around aluminum, titanium and their alloys powders. This thesis is part of this project and aims to contribute on the one hand to the determination of the safety parameters, and on the other hand to the comprehension of combustion mechanisms of these powders. For such, eleven metal powders were selected including four pure powders and seven alloys. Their combustion characteristics were studied in a 20 liter spherical bomb and in a Hartmann tube. In support of these devices, optical diagnostics, in addition to the pressure sensor of 20 liter spherical bomb, such as a two-color IR pyrometer and a UV-Visible spectrometer were used. The combustion mechanisms were interpreted by combining a thermodynamic equilibrium approach with the combustion products characterization. The results obtained in those different experimental configurations showed that pure powders are more sensitive and more severe to explosion than their alloys. In the combustion products analyzes, it is noted the presence of crystallized and amorphous phases witch showed the complexity of the mechanisms formation of combustion products. In all cases, it appears that oxygen and nitrogen are two reactants during combustion, as evidenced by the analysis of the products. The proportion between oxide and nitride is directly controlled by dust concentration. These results provided new information about the combustion of pure powders and their alloys and showed that we need to evolve combustion models.
Document type :
Theses
Complete list of metadatas

Cited literature [115 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02985934
Contributor : Abes Star :  Contact
Submitted on : Monday, November 2, 2020 - 3:36:07 PM
Last modification on : Tuesday, November 3, 2020 - 3:21:12 AM

File

myriam-millogo_4101.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02985934, version 1

Citation

Myriam Millogo. Allumage, combustion et explosion des poudres d'aluminium, de titane et de leurs alliages. Autre. Université d'Orléans, 2019. Français. ⟨NNT : 2019ORLE2006⟩. ⟨tel-02985934⟩

Share

Metrics

Record views

58

Files downloads

19