Characterisation of 17-4PH metallic powder recycling to optimise the performance of the selective laser melting process

The advantages of Additive Manufacturing (AM) processes are well known. Particularly, those AM techniques which are used to manufacture metallic parts are of great interest to industry due to the good mechanical behaviour of metallic alloys. Despite this, the quality of the manufactured parts is still an important issue due to the wide range of parameters that can affect them. In some powder bed fusion techniques, such as Selective Laser Melting (SLM), not all the initially distributed metallic powder is used in the process. There is an unmolten portion that can be recycled to ensure both the economic and environmental viability of the process. Even though this powder is unmolten, it is thermally affected due to the high temperatures attained during the process. This fact affects the powder properties and, consequently, the properties of the manufactured parts. Therefore, an analysis of the recycling effects of SLM metallic powders is an important issue in order to establish good recycling procedures and to optimise the process performance.