E-Beam micro-hole drilling features high productivity of 2,000 holes per second and a high aspect ratio of 10 (depth/diameter). It can be used for the fabrication of nozzles and filters that require several holes. The hole-formation mechanism comprises 1) melting the sample by the energy exchange of e-beam and 2) removing the molten sample by the explosion of the backing material. Accordingly, hole-formation mechanism studies have focused on the effectiveness of backing material and the workpiece’s melting characteristic. This study investigated the melting depth characteristics depending on the beam current and exposure time that determines the E-Beam dose. The experiments were conducted without using the backing materials with an aim to investigate the melting characteristic of the workpiece itself. The results showed that the increase in the exposure current led to an improvement in the melting depth. The results were verified based on the comparison with the results of the process involving the backing material.

The aim of this paper is to investigate the improvement of surface characteristics of Stellite21 deposited layer by powder feeding type of direct energy deposition (DED) process using a plasma electron beam. Re-melting experiments of the deposited specimen is performed using a three-dimensional finishing system with a plasma electron beam. The acceleration voltage and the travel speed of the electron beam are chosen as process parameters. The effects of the process parameters on the surface roughness and the hardness of the re-melted region are examined. The formation of the re-melted region is observed using an optical microscope. Results of these experiments revealed that the re-melting process using a plasma electron beam can greatly improve the surface qualities of the Stellite21 deposited layer by the DED process.