Theoretical and experimental investigations on nano-finishing of internal cylindrical surfaces with a newly developed rotational magnetorheological honing process

Abstract

In the current scenario, the advanced industries are using highly sophisticated types of machinery. These types of machinery use numerous cylindrical components made with superior materials and technology. For obtaining the nano-level finished interior cylindrical surface with high accuracy and high production rate, a newly developed rotational magnetorheological honing (R-MRH) process is employed on the cylindrical objects. This process is applicable in internal nano-finishing of cylindrical molds, hydraulic and pneumatic valves, aerodynamic bearings, gears, cylindrical barrel, and cylinders used in medical devices, etc. In the present work, the cylindrical workpiece is also made rotational in the reverse direction of the MRH-tool rotation unlike the existing MRH process. The rotating motion of the workpiece cylinder caused an increment in relative motion of the active abrasive particles against the interior surface of the workpiece cylinder. The effect of the rotational speed of the workpiece cylinder along with movements of the MRH-tool on change in surface roughness is investigated theoretically and experimentally in this work. Theoretically, it is found that the simultaneous motions of tool and cylindrical workpiece in the opposite direction to each other increase the finishing rate. To validate the theoretically increased finishing rate due to the rotating cylindrical workpiece, and to examine the effect of the rotational motion of the cylindrical workpiece on finishing performance, the experiments are conducted with the R-MRH process. The reduction in surface roughness is found as 71.71% in 60 min with the existing MRH process for the stationary cylindrical workpiece, whereas it is reduced to 83.83% in only 40 min with the R-MRH process for the rotational cylindrical workpiece. The significant change in surface roughness value with reduced finishing time validates the improved efficacy of present R-MRH process for its more utility in industries.