Investigation into freeform fabrication of multi-material parts by 3D welding and milling process

Solid Freeform Fabrication (SFF) gives engineers a new freedom to build parts which have proved impossible to manufacture using conventional techniques. However, the surface finish and accuracy of SFF parts are still lower than those of parts which have been machined in conventional operations. A process combination of additive and subtractive techniques is currently being developed in order to overcome this problem. The hybrid approach called "3D Welding and Milling" uses welding as an additive and conventional milling as a subtractive technique, thereby exploiting the advantages of both processes. In this paper, the attempt was made to build multi-material parts, especially molds, by using two different deposition strategies. The results show that it is a feasible approach to build multi-material metal parts directly.