Interfacial microstructure and mechanical properties of GH5188/CuCrZr combustor-nozzle components fabricated by hybrid LPBF/LDED additive manufacturing

Copper/cobalt multi-material components can integrate high temperature resistance and high thermal conductivity, showing great potential for aerospace engine combustion chambers. However, the single laser directed energy deposition (LDED) process has low accuracy and cannot print fine cooling channels, and the single laser powder bed fusion (LPBF) process features low efficiency and limited printing area. In this work, the interfacial microstructure and mechanical properties of CuCrZr/GH5188 multi-material parts fabricated by LPBF/LDED were investigated, and combustor-nozzle components were successfully printed. The results show that increasing laser power and scanning speed within an appropriate process window can improve elemental distribution at the interface and reduce crack defects, leading to a nearly gradient mixing of interfacial elements. Nevertheless, the risks of excessive spattering and fuming under high laser power should be noted. The ultimate tensile strength of the CuCrZr/GH5188 bonded interface in thin-walled samples was 294 MPa, which is close to the intrinsic strength of the CuCrZr substrate. The integrated combustor-nozzle prototype fabricated under optimized parameters exhibited a dimensional accuracy of ±0.2 mm, free of macroscopic defects, with intact internal cooling channels. This work verifies the engineering feasibility of hybrid LPBF/LDED additive manufacturing of CuCrZr/GH5188 combustor-nozzle components, providing theoretical support and technical routes for the integrated manufacturing of high-temperature hot-end components in aero-engines.