Development and evaluation of interfacial structures for hybrid manufacturing

Abstract

Hybrid manufacturing is a combination of additive (deposition) and subtractive (machining) manufacturing in a single machine tool. Such a system can be used for near net shape manufacturing and component repair using either similar or dissimilar materials. This dissertation investigates methodologies for laser wire-fed hybrid manufacturing processing for commercially available systems and demonstrates how process parameters can be optimized resulting in a deposition rate of 2.5 kg/hr of steel. Integrated into a single system, transition between additive and subtractive manufacturing can occur immediately and be leveraged to generate large components by alternating between the processes. This dissertation investigates how this capability can reduce overall cycle time by up to 68%, improve average elongation to failure by 22%, and reduce average porosity by 16%. With hybrid manufacturing systems, it is now feasible to control the interfacial conditions between the substrate and deposition. Other deposition processes require substrates to be planar, but hybrid manufacturing’s subtractive capability allows for unlimited surface structures and conditions. This dissertation further investigates multiple surface structures for similar and dissimilar materials but concludes that these structures do not result in any improvement of mechanical properties. As a result, these investigations has not only set the foundation for laser wire-fed hybrid manufacturing process development, but has influenced the direction of future research in the field.