Abstract: Understanding materials at their atomic level is important given that the macroscopic properties of a material are intricately linked to its nanoscale structure. This plays a pivotal role in advancing structural materials since their performance is significantly influenced by factors such as composition, and microstructure which consist of different interfaces, crystalline phases, and defects. 

In the automotive and aerospace industries reducing the weight of materials is critical to enhance fuel efficiency without compromising safety and performance. Lightweight aluminum alloys are extensively studied to replace heavier materials in these sectors. This work offers a comprehensive characterization of the evolution of various precipitates within aluminum alloys under laser treatment conditions, aiming to enhance their mechanical properties.

The thesis also delves into understanding the diffusion and dissolution mechanisms of metal nanoparticles on or into metal oxides. Metals like gold, in their bulk form, are traditionally considered chemically inert and inefficient as catalysts. At the nanoscale, however, as the particle size decreases, their catalytic activity towards various reactions significantly increases. Our exploration of these systems under in situ TEM heating has provided valuable insights into the structure-function relationships of these interfaces. This knowledge can be employed in optimizing the production of nanomaterials with enhanced interface properties.

KEYWORDS: Aluminum alloys, precipitate hardening alloys, SLV, TEM, in situ TEM