ABRASIVE PROPERTIES OF MAGNETO-RHEOLOGICAL FLUIDS FOR IMMERSED TUMBLING PROCESSES

Micro-milling tools, widely used in industrial environments for manufacturing micro- and precision components, experience premature tool failure primarily due to cutting edge wear. In immersed tumbling processes, the cutting edges can be post-processed to gain homogeneous edge radii and reduce the tool wear. However, immersed tumbling processes exhibit limitations in the adjustability of the cutting edge geometry as well as difficulties in the directed processing of main and secondary cutting edges. Therefore, a novel immersed tumbling process using magnetorheological fluids (MRF) is investigated to enable a directed processing method in an applied magnetic field. The focus of this work is to identify a suitable composition of the MRF for an increased abrasive effect on high-speed steels. For this purpose, variously composed MRF samples are blended with abrasive particles and then examined using a custom-designed test bench that replicates the immersed tumbling process. The material removal rate on high-speed steel specimens is determined by optical analysis of the edge rounding of the samples before and after the abrasive process in order to find an optimized abrasive MRF composition with the highest material removal rate on high-speed steels.