Economic and Ecological Evaluation of Hybrid Additive Manufacturing Technologies Based on the Combination of Laser Metal Deposition and CNC Machining

Abstract

Hybrid additive manufacturing technologies combine selective material deposition with a conventional milling process in one machine, enabling the production of complex metal parts and reducing the need for part specific tools. The hybrid technology offers technological advantages compared to more established additive fabrication processes, such as powder bed fusion. Compared to powder bed based additive processes, which are currently in a prevailing positon regarding AM adaption, hybrid additive technologies enable increased build rates, enhanced build volumes and a reduction of machine changes. In the Laser Metal Deposition (LMD) process, metal powder is deposited through a nozzle and melted by a laser on the surface of the part. By integrating the LMD process into a machining center, good surface roughness and low tolerances can be realized by means of e. g. milling without reclamping. In comparison to powder bed based processes, cost and resource input have not been investigated in detail. In this study, hybrid additive manufacturing technologies are analyzed regarding cost and resource input. A cost model for hybrid additive processes is introduced that enables the analysis of the manufacturing cost structure for a given part. Furthermore, the resource inputs for the operation of a hybrid production machine are estimated.