High-temperature alloys pose significant challenges in additive manufacturing. These materials have unique properties, such as high resistance to mechanical and chemical degradation when exposed to high temperatures. Furthermore, when these alloys are used to produce hybrid components with other similar alloys, investigating their surface integrity is critical because any residual stress can lead to early stage cracks and poor fatigue performance. In this research, a hybrid manufacturing approach is employed to produce components from difficult to weld alloys, i.e. CM247LC deposited on IN718 through a laser based direct energy deposition (L-DED) process. The surface integrity, mechanical properties and microstructure of such hybrid components is investigated, especially their welding/joint areas. Crack-free processing regimes were established to deposit CM247LC while mitigating the negative effects onto the microstructure of the Inconel substrate. Especially, the thermal gradients were managed to deliver crack free sections of CM247LC with good interface bonding, strength and fine microstructure. It is important to note that this is achieved without any significant preheating that contrasts with what is reported in other investigations so far. Furthermore, end-use hybrid blisks with deposited CM247LC blades onto Inconel 718 disks (HUB) were manufactured and then machined within a single processing set-up. The results show that the substrate thickness, the machining between the deposited layers and the final machining and heat-treatment play a role in reducing residual stresses. Ultimately, such hybrid manufacturing approach can be considered a new solution for producing such components and also for their subsequent repair.

Hybrid manufacture of components by combining capabilities of replication and additive manufacturing processes offer a flexible and sustainable route for producing cost-effectively small batches of metal parts. At present, there are open issues related to surface integrity and performance of such parts, especially when utilising them in safety critical applications. The research presented in this paper investigates the ductility amplification of hybrid components produced using metal injection moulding to preform and then build on them customisable sections by laser-based powder bed fusion. The properties of such hybrid components are studied and optimised through the use of non-conventional post treatment techniques. In particular, hot isostatic pressing (HIP) is employed to improve mechanical strength and to produce hybrid components that have consistent properties across batches and throughout the samples, minimising microstructural heterogeneities between fabrication processes. Thus, the investigated post-processing method can offer an extended service life of hybrid components, especially when operating under severe conditions. The optimised post treatment was found to increase the hybrid components’ strength compared to as-built ones by 68% and ~11% in yield strength (YS) and ultimate tensile strength (UTS), respectively. Subsequently, leading to a great pitting resistance, thus, making HIP samples suitable for corrosive environments. The advantages of the HIP treatments in comparison to the conventional heat treatment of hybrid components are discussed and also some potential application areas are proposed.