Effect of Si on the SLM Processability of IN738LC

Abstract

Selective laser melting of high gamma-prime strengthened superalloys such as IN738LC is of interest in stationary gas turbine applications. Differences have been obtained for the hot cracking susceptibility of different powder batches during SLM processing and indications were found that also minor elements influence the SLM processability. By processing a specific powder batch blended by different amounts of pure silicon, the detrimental effect of this element during SLM could be shown. Therefore, the control of this minor element is crucial to decrease the hot cracking tendency and can extend the SLM processing window of this alloy.