Functionalization of Electron Beam Melting parts in order to guide finishing operations par Adrien Dolimont
Additive Manufacturing (AM) technologies were initially devoted to rapid prototyping for product visualization. Now it has been proved that they can be used to produce real parts with the required mechanical properties. They are widely implemented to produce biomedical, aerospace and rapid tooling parts. Their evolution has permitted a shift from prototyping to production of parts with good mechanical properties. The interest of those technologies is that they use less material and produce less waste than traditional techniques. They also unlocks the design limitations unlike the other processes. For all these reasons, it is possible to claim that geometrical complexity is for free thanks to AM technologies.
The manufacture of metal industrial parts is well known in terms of control of the process and performance of the materials for traditional processes (machining, casting, welding, etc.). Additive Manufacturing technologies are a booming field that reopens the reflection on those topics. This thesis responds to the need of a better understanding of the Electron Beam Melting (EBM) process and more particularly to the mastery of the process in view of an optimal finish of EBM parts. To this end, the functionalization of parts build by EBM process i.e. process characterization, definition of machining allowance, machining characterization, mechanical behavior, surface finish and so on had to be studied.
The present research is divided into 3 main areas:
Dimensional characterization: accomplishment of a dimensional analysis on a large number of pieces, comparison of the EBM process to other manufacturing processes by an original capability approach and proposal of an original methodology to limit the number of calibration while keeping an acceptable dimensional quality.
Surface characterization: attempt to improve the surface quality in situ by testing and modifying a wide range of process parameters.
Mechanical properties of EBM Ti6Al4V parts: investigation of several aspects of mechanical characterization of EBM Ti6Al4V from mechanical properties to residual stress in EBM Ti6Al4V parts.
Thanks to useful experiments precious indications that were not currently in the literature could be given and many questions that were asked in these three main areas could be answered.