Manufacturing of High Pressure Die Casting Die Inserts Using SLM

Abstract

Dies for high pressure die casting are normally manufactured by machining of slabs of tool steel to the required dimensions. This manufacturing requires several steps such as rough machining, heat-treatment, EDM (electro discharge machining) and polishing. With the AM (additive manufacturing) method SLM (Selective Laser Melting) it has become possible to print the dies fully or in part. Several advantages are expected, such as a better thermal distribution in the die in service and thereby extended die life and better component quality. This is due to the possibility of making the cooling channels conformal. There are also expectations of reduced time and cost in the manufacturing process due to fewer manufacturing steps and better material utilisation. Hopes are to print a net shape or near net shape that can be used directly as a die component. In this paper it is investigated to what extent this can be fulfilled by printing two die inserts to be used for casting fatigue test samples of aluminium. They were printed on a 3D Systems ProX DMP 300 in maraging steel powder. The result is that it is possible to obtain a sufficiently smooth surface die surface. However, the current design with an SLM insert fitted in a machined die makes extensive post printing manufacturing necessary.