The document presents some achievements in the field of heterogeneous materials and assemblies within three laboratories. They are grouped into three thematic sections highlighting three areas of competence developed in parallel during fourteen years of research. In the first chapter, the issues are discussed from the point of view of the process. The objective is to understand how each process parameter affects the microstructural or mechanical characteristics of the materials or bonding. The second chapter focuses on the microstructure of materials and their evolutions, mainly during the assembly process. Different analysis techniques are used to study the microstructures generated during the material elaboration or assembly, in connection with the elaboration conditions, to better understand the transformations involved, and the possible effects of these changes on the mechanical properties. Finally, in the third chapter, the mechanical characterization is a major concern, and the effects of elaboration process and microstructure are highlighted only to clarify their relationship with the mechanical properties of the materials, assemblies, and structures they form.
