Characterization of Direct Laser Metal Forming Technology for the Restoration of Mold Surface

Direct laser metal forming technology was applied to restore the damaged mold surface. In order to estimate melting characteristics of the 20 mu m. Fe-Cr-Ni powder, single layer experiments were performed at various levels of heat input. The process window of the 20 mu m Fe-Cr-Ni powder provided feasible process parameters for the smooth regular surface. The cross hatching scanning strategy on the multiple layer experiment was performed to reduce the thickness non-uniformity of edge portions compared with the one direction scanning. To estimate the coherence between the melted powder and the basematal, the tendency of hardness distribution has been observed. The hardness of the melted and the remelted zone was distributed from 400HV to 600HV. It is over 2 times compared of the hardness of the basemetal. Experimental results show that the mold restoring process using direct laser metal forming can be successfully applied in the mold repair industry.