Direct Laser Re-melting of Tool Steels

摘要

The effect of powder production route and powder composition on the processing of tool steels by direct laser re-melting (DLRM) has been investigated. The powder-manufacturing route has been shown to have a significant effect on porosity, with gas-atomised powder producing a higher density final material than water-atomised powder. The role of alloy composition in controlling processability was examined by testing two tool steels (M2 and HIS), with H13 being found to be easier to process under all conditions. Further experiments, where carbon and silicon were added to H13 and iron powders, showed that increased carbon levels reduced processability, even though the melting temperature of the steel was reduced. Silicon content was found to have little effect on processability.