A new polishing method of metal mold with large-area electron beam irradiation

A new polishing method by large-area electron beam (EB) irradiation is proposed in this study. In the large-area EB irradiation equipment used here, an EB with high energy density is irradiated without focusing the beam. An EB irradiation in a few microseconds with a maximum diameter of 60 mm can be used for melting metal surface instantly. The experimental results made it clear that the surface roughness decreases from 6 μmRz to less than 1 μmRz in a just few minutes under a proper machining condition. The corrosion resistance of metal mold surface also could be greatly improved by large-area EB irradiation. Furthermore it is clarified that even the surface roughness of tilting surface close to 90° could be well improved. Therefore, large-area EB irradiation method has a high possibility to become a high-efficiency polishing method of metal mold.