USE of DIRECT METAL DEPOSITION for LAUNCHER PART

For a large number of applications, additive manufacturing is becoming very attractive due to its capacity to manufacture products with complex and optimized designs which are not possible with conventional manufacturing processes.

Selective laser melting (SLM) and electron beam melting (EBM) are the flagships of the AM technology, especially for aerospace applications. However, limitations in sizes and scanning speed make them unsuitable to produce large parts. In this context, Direct Melting Deposition (DMD) can be considered, thanks to larger deposition rates and larger positioning range. With this technology, it is possible to manufacture large complex blanks ready to be machined with little waste, which may be a decisive advantage in comparison with complex die forgings, forged rolled rings or large machined plates.

In this study, we focus on powder deposition using direct melting process (DMD) to produce a large space aluminium product that is expensive to build with conventional methods and requests a long lead time. Two main objectives are aimed: the setup of the process with the determination of the parameters to be used to produce healthy pieces and the demonstration that the manufactured piece meets the requirements.

The optimized deposition parameters will be compared for two Al powders: AlSi10Mg and Scalmalloy®. The internal health will be presented as a function of the main deposition parameters (energy density, powder flow,...), for both powders large differences of density are observed. On samples coming from built walls, the hardness and the mechanical properties will be shown. The strategy to build a demonstrator will also be explained.