Study on high efferent micro-deburring by large- Area EB irradiation

A large- Area Electron Beam (EB) irradiation method has been developed recently. High energy EB with uniform energy distribution can be obtained without focusing the beam and they can lead to instant melting or evaporating of metal surface. Previous works clarified that surface finishing and modification were possible for various materials, such as metal molds and biomaterials. On the other hand, it was also confirmed that convex corner tips on the workpiece was rounded due to preferential material removal at the tip by large- Area EB irradiation. By using this phenomenon, we also reported that the micro burrs on SKD11 which were generated with EDM, were completely removed. In this study, micro-deburring on magnetic and non-magnetic materials is investigated. High efficient micro-deburring is also tried by using magnetic block and thermal insulation plate. SKD11, Ni, Cu, Ti-6Al-4V and Al are used as magnetic and non-magnetic materials. Micro burrs whose height are about 40 μm, are generated at the edge of many holes machined by EDM drilling. Pulse duration Dp and pulse frequency fp of large- Area EB are fixed at 2 μs and 0.125Hz, respectively. The energy density Ed and number of irradiation N are varied in order to investigate the effects of Ed and N on deburring characteristics. Burrs are completely removed on magnetic workpieces of SKD11 and Ni at Ed=15 J/cm2 over N=30 shots, while complete removal of burrs is difficult for non-magnetic workpieces of Cu, Ti-6Al-4V and Al. When the magnetic block is placed under the Cu, complete removal of burrs on Cu is successfully done due to concentrating of EB. Moreover, removal ratio of burrs on Cu is increased by inserting the thermal insulation plate between Cu and magnetic block. These results suggest that high efficient micro-deburring can be done on any materials by using the magnetic block and insulation plate.