Industry case study: process chain for manufacturing of a large hybrid hot stamping tool with conformal cooling channels

Conformal cooling channels introduced into manufacturing tools is fast becoming an industry standard, as it has proven to significantly reduce cycle time during operation. Introducing conformal cooling channels into a metal tool (such as a hot forming punch or injection moulding core) is a challenge on its own and often requires expertise in both additive and subtractive processes to execute efficiently. Another issue is that of the inherent constraints of both the additive and subtractive processes, which prohibit the effective use of these processes for manufacturing of specific tool designs. Thus, often a balance needs to be met, where a hybrid process is sought to utilise the advantages of both processes while limiting the disadvantages. This study suggests a viable process chain for manufacturing a large hybrid tool using milling and selective laser melting processes. A large (745 × 174 × 78.7 mm) hot forming punch with conformal cooling channels was produced by splitting the tool into four sections to fit into the build envelope of the M2 cusing machine from Concept Laser GmbH. Various considerations and challenges are highlighted.