Process planning for iterative, in-envelope hybrid manufacturing in the presence of machining allowances

The objective of this research is to develop a method for an iterative hybrid manufacturing (HM) process to create straight wall geometries in the presence of tool reach and access limitations. The method specifically addresses the management of machining allowance added during deposition – required to be machined away, but also used to support subsequent deposition operations. This research will present the implementation of this method with an HM system utilizing directed energy deposition (DED) in combination with computer numerical control (CNC) machining. Today’s manufacturing environment is rapidly adopting hybrid manufacturing technologies, particularly those with the capability of producing end component geometry through both additive manufacturing (AM) and subtractive manufacturing processes. However, much of the use of these unique technologies is done in isolation, first producing a component’s entire geometry via an AM process, and subsequently following with a subtractive process to produce the final surface geometry. This sequential approach fails to take advantage of the integrated nature of hybrid manufacturing, which allows changing between the two processes without adjusting fixturing. This is largely due to the complexity of these process changes and the implications removing material may have on the next application of AM methods. Utilizing a method that iteratively deposits material and then machines that deposition provides the ability to create unique and previously unattainable geometries. The proposed method will reduce the issues associated with material removal before a DED-AM process