Fundamental study on micro-deburring by large-area EB irradiation

In a large-area electron beam (EB) irradiation method developed recently, high energy EB can be obtained without focusing the beam. Then the large-area EB of 60mm in diameter with uniform energy distribution can be used for instant melting of metal surface. The previous studies clarified that the surface smoothing of metal mold made of steel, cemented carbide and ceramics can be performed efficiently. Also this method can be applied to the surface finishing of biomaterials, such as stainless steel and titanium alloy. In this method, the sharp edge is rounded to about half hundred microns in radius under relatively high energy density conditions, since the material removal remarkably progresses there due to the electron concentration and heat accumulation at the edge. In this study, the possibility of micro deburring was investigated by using the preferential edge removal effect in the large-area EB irradiation. Experimental results showed that the micro-deburring was possible by large-area EB irradiation, and the burr height decreased with increasing the energy density of EB and the number of irradiation. The burr of about 10um generated in EDM could be removed completely. Furthermore, micro-burrs at the edge of several small holes could be removed at once.