Intelligent process planning and control of DED (directed energy deposition) for rapid manufacturing

This research has been conducted to develop computer aided manufacturing software, which can generate NC programs for a five-axis directed energy deposition (DED) type additive manufacturing system with following three focuses: 1. How to maintain consistent formation of a melt pool on the surface of the workpiece. 2. How to generate three-dimensional deposition path efficiently when a 3D part model is given. 3. How to control process parameters during additive operation. For focus 1, the work orientation has been controlled such that the surface to be deposited can remain perpendicular to the nozzle which is fixed to gravity direction and minimize distortion of the laser spot and powder distortion on the workpiece surface. For focus 2, a unique path generation method has been proposed based on the reverse play of a subtractive machining path, which removes the entire part to the null. For focus 3, preoperative process parameters control has been introduced to achieve the specified volumetric deposition rates along the additive tool path, which is equated with the material removal rates along the subtractive machining tool path. With methods mentioned above, the dedicated CAM system, CAMAM, has been prototyped and its feasibility has been verified experimentally by applying the NC program generation strategies to deposit several parts.