Abstract
The inside of the molding die fabricated by additive manufacturing can locate cooling channels efficiently. However, the internal face of cooling channels has the problem that face roughness of the cooling channels is not uniform due to the partially melted powder. In this research, the method of finishing the internal face by free abrasive grain is proposed. As a result, the internal face roughness in the cooling channel was improved significantly by the removal of the partially melted powder. The cooling channel of smaller diameter has high processability due to the high velocity of flow by passing through the channel.
