Abstract
In order to realize both high-efficient forming with the wire arc additive manufacturing (WAAM) and precise forming with the laser metal deposition (LMD) for some complex-structure and high-precision parts, a hybrid metal additive manufacturing method is proposed. The part is decomposed into sub volumes, then the sub volumes with relatively simple-structure features are formed through WAAM as a substrate, and the other sub volumes with more complex-structure or small-sized features are formed through LMD on the former substrate. However, the mechanical properties of the bonding interface would be reduced, if the later sub volumes are directly deposited by LMD on the rough WAAM substrate surface. In order to avoid unnecessary machining process between WAAM and LMD for high efficiency, and ensure the mechanical properties of WAAM-LMD bonding interface the laser remelting method is applied for improving the profile of WAAM substrate surface. The simulation model of heat transfer and fluid flow in the laser remelting process is established, the influence of the laser power and the scanning speed on the surface-profile improvement is researched by simulation and verified by experiments, Based on that the remelting process parameters are optimized. Furthermore, based on the WAAM formed substrate, the LMD formed volumes are deposited directly, after surface milling and after laser remelting, respectively. Then the microstructure and the mechanical properties of the bonding interface are compared among the three process methods, the feasibility of the laser remelting method for improving the bonding interface performance is verified.
Effects of defects on mechanical properties in metal additive manufacturing: A review focusing on X-ray tomography insights
