Design and development of Ball-end magnetorheological finishing tool for nano polishing of BK7 glass

Surface quality and roughness are major effective parameters on the function of optic components. This study developed a new design of the Ball-End Magnetorheological finishing tool with the ability to mount on a three-axis CNC milling. In the new design, a new concept of the cooling system was used for cooling the internal and external surfaces of the electromagnetic coil, and optimizations on magnetic flux distribution were performed. With the aid of magnetostatic simulation in Ansys Maxwell software, the tool’s capability for producing magnetic flux density was tested. The capability of a new tool for polishing non-ferromagnetic BK7 glass was tested by selecting optimized process parameters like working gap and magnetizing current. An experimental magnetic flux density test with the gauss meter showed that the newly designed BEMRF tool can generate enough magnetic flux density for polishing BK7 glass. The finishing test showed the tool’s ability to create enough indentation force on the workpiece’s surface and reduce surface roughness.