Investigation on the design of a novel selective laser melted insert for extrusion dies with conformal cooling channels

The thermal control and the maintenance of a uniform temperature in the extrusion process of aluminum alloys is a crucial task in order to generate sound profiles with high press productivities. This can be accomplished through liquid nitrogen flowing in Conformal Cooling Channels (CCC). The Selective Laser Melting (SLM) additive technology offers an optimal solution for an unlimited flexibility of the cooling system, thus allowing tailored cooling strategies. In the present work, a smart thermally controlled die made by AISI H13 was designed aimed at maximizing and regulating the cooling efficiency by means of CCC. In the novel die concept, the expensive SLM insert with CC channels, has been integrated into a conventionally machined steel housing. A comprehensive numerical investigation has been performed in order to check the insert designs mechanical and thermal performances both in uncooled and cooled conditions. Then, eight inserts were additively manufactured by means of the SLM process with the aim to preliminary verify their experimental feasibility and overall quality. As main results, it was numerically proved the capability of the novel insert design to allow a significantly increase of the production rate and it was experimentally demonstrated the insert manufacturability throughout the SLM technology.