Résumé
Additive manufacturing (AM) is changing fundamental concepts of design, engineering and production. Conversely to subtractive manufacturing, this technology consists in building a part following successive deposition of metallic layers. The deposited metal can be either a powder or a wire. Such technology requires that the part design integrates this building procedure as well as its mechanical functionalities. Metal additive processes such as Wire and Arc Additive Manufacturing (WAAM) employs a metallic wire as base material and an electrical arc source for melting it and building layer after layer the metallic part. WAAM is currently in a maturation phase, in order to produce customized parts, for e.g: medical, motorsports, aircraft and aerospace. It is now possible to create 3-D metal components with the required mechanical properties. WAAM technology enables manufacturing parts and devices with fairly complex geometry with high deposition rates in comparison to powder based AM. There is low material loss what makes WAAM as a promising alternative to traditional substractive manufacturing. In the proposed communication, The Cold Metal Transfer (CMT) arc welding process is used to deposit metal layers on a steel plate. CMT is a short circuit controlled metal inert gas (MIG) welding process working at low heat input. CMT uses a huge numbers of parameters that controls wire feeding, welding intensity and voltage. Some of these parameters are investigated in order to observe their influence on each deposited layer. The deposited layers are 3D scanned in order to get the geometric characteristics (wetting angle, height, width, deposition rate …). These observation are necessary to establish an experimental database of CMT parameters in order to fabricate metallic components in WAAM manner. Firstly the study focuses on for the study of single weld deposits, then investigations are carried out on multi-layer overlapped bead in order to achieve high surface quality and reliability as well as dimensional accuracy of the fabricated part.