Additive friction stir deposition of aluminium 7075 : process window, microstructure and mechanical properties

This research provides a comprehensive approach to a new Additive Manufacturing process called Additive Friction Stir Deposition (AFSD) process. Due to its novelty, the AFSD technique is not yet well characterised and integrated within the industrial environment. Much remains to be discovered, from the advantages to the many properties and even to the simple execution of the process itself. This master thesis therefore provides a detailed overview of most concepts involved in this new manufacturing process for metals. It also highlights an in depth study of several aspects of the AFSD process. In this research, the feed material used is Al-7075. The first part of this document provides the necessary knowledge for a comprehensive understanding of the research carried out. In this sense, the method of using Additive Friction Stir Deposition is described in a general way and will be more specific the experimental part later on. It also contains the details of the research conducted on this new technique. In the second part of the document, a whole section will explain the methods followed for the different experiments and provide information on the raw material used. Next, it will cover the following topics: process window, microstructure and mechanical properties. The machine operating parameters are found in the process window and how the corresponding aluminium parts can be produced with their effects. A series of analyses will then be carried out, including the general view of the deposit and an overview of the section. The microstructure is also analysed in part according to different parameters and especially the comparison between as-built and with post processing samples. In addition, the mechanical properties of the manufactured parts for the conclusive parameters are part of this research. For the mechanical parts, most of the analysis will be made with microhardness and tensile results. Also, the correlations between the results found in each topic will be part of the analysis. The document provides an understanding of correlations between operational parameters and microstructure and their related mechanical properties. It further shows the strengths and capabilities of AFSD to bridge the gap between scientific research and industrial applications.