22 April 2022
16:15
Lovain-La-Neuve
Place Croix du Sud, SUD 19
For the degree of Doctor of Engineering Sciences and Technology
Aluminium alloys are widely used as structural materials in transportation, space and construction. Despite the excellent combination of lightweight with sufficient strength, to remain competitive on the market, several properties of Al alloys should be further enhanced, such as strength properties and damage tolerance. One way to improve the strength of Al alloys is to combine them with reinforcements, thus processing Aluminium matrix composites (AMCs). These materials present several advantages compared to Al alloys, such as higher strength, elevated temperature resistance and lower thermal expansion coefficient. In addition, to improve damage tolerance of Al alloys and AMCs, Friction Stir Processing (FSP) can be used. However, the classical approach of damage prevention is not the only solution to improve damage tolerance and meet materials sustainability requirements. Instead, damage management approach can be used to achieve alloys longevity, among which self-healing strategies are good approaches. 
In the present study, a new healable Al alloy/composite presenting healing behaviour was produced by FSP. A new Programmed Damage and Repair (PDR) healing concept was proposed. In this concept, the damage provoked by the load appears on sacrificial particles. When the selected healing heat treatment is applied, healing occurs using the matrix atoms as a healing source. Healing was demonstrated using in-situ heating under nanoholotomography and TEM.
Jury members :
- Prof. Aude Simar (UCLouvain, Belgium), supervisor
- Prof. Hosni Idrissi (UCLouvain, Belgium), supervisor
- Prof. Hervé Jeanmart (UCLouvain, Belgium), chairperson
- Prof. Pascal Jacques (UCLouvain, Belgium), secretary
- Dr. Eric Maire (INSA Lyon, France)
- Prof. Sybrand van der Zwaag (TU Delft, the Netherlands)
- Dr. Willimas Lefevre (Université de Rouen, France)