Abstract
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.
Highlights
The manufacture of metal components by employing flexible processes such as layerwise manufacturing and/or combining them with other complementary processes have attracted significant research interests recently, due to their potential applications in medical, aerospace, energy, and automotive industries
It was reported that post treatments, such as heat treatment, hot isostatic pressing (HIP) and surface finishing of as-built components could improve their relatively poor surface integrity to meet the technical requirements in many applications [10,11,12,13]
It had a negative impact on the metal injection moulding (MIM) preforms as it introduced larger pores, and some damage was observed in Figure 2b,c, probably due to the expansion and release of entrapped gasses and/or residual binders from the bulk during the heat treatment (HT) cycle
Summary
The manufacture of metal components by employing flexible processes such as layerwise manufacturing and/or combining them with other complementary processes have attracted significant research interests recently, due to their potential applications in medical, aerospace, energy, and automotive industries. Attempts to combine its capabilities with those of primary processes with higher production rates, such as metal injection moulding (MIM), gravity and die casting, have been reported recently and to selectively allow partial customisation and/or personalised hybrid components with partial production with time and cost saving bulk processes in various configurations for their envisaged applications [14,15,16] Such hybrid components manufacture (HCM) requires specialised tooling solutions to implement it in production lines, and to integrate metal AM with other complementary processes for producing small to medium batches cost-effectively. The heating rate was selected considering that the relatively thin hybrid samples were built using MIM preforms containing some very small residue of the binder, in particular it was reported that approximately 1% remained after the debinding step [49]. The mechanical strength and microstructure of hybrid components in the three sets of samples were analysed and compared
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
