Digital Testing of Hybrid Components Manufactured by L-DED and Forging

Abstract

Manufacturing effectiveness is highly demanded in the aerospace industry; therefore, hybrid manufacturing technologies have gained considerable attention in order to overcome the limitations of a single manufacturing technology. Actually, the hybridisation of different manufacturing processes consists in taking advantage of the strengths of each process and compensating the weaknesses. In this work, the Laser Directed Energy Deposition (L-DED) process is hybridised with forging. The L-DED is an Additive Manufacturing technology which enables to add material on existing parts in order to add geometrical details or repair damaged areas. Thereby, the flexibility of the L-DED can be combined with the high-productivity and lower cost of the forging. A nickel-based superalloy employed in aeronautical applications is selected, the Inconel 718, which is suitable for high-temperature applications, such as the turbine casing of jet engines. Depending on the manufacturing process and final heat treatment, the Inconel 718 presents different properties. Hence, simulation tools are considered as a key element for the material properties characterization, where digital testing is becoming a fundamental pillar. Thermal and mechanical simulations with FEM enable the evaluation of the complete thermal history of the part and the resulting mechanical behaviour in-service conditions. In this work, the feasibility of hybridising forging and L-DED is studied. For this purpose, the resulting properties of the parts manufactured by each individual process are quantified and the interaction between both processes is analysed. Moreover, a test part is manufactured to show the hybridisation capabilities. Afterwards, to determine the behaviour of such demonstrator, a digital testing is performed by means of finite element modelling. Both thermal and structural analysis are carried out and the results obtained for the hybrid component are compared with those of an entirely forged part, focusing on a critical assessment of the performance of each manufacturing approach.