Experimental analysis of magnetorheological finishing of blind hole surfaces using permanent magnet designed tools

Abstract

Permanent mould dies are used for various plastic injection moulding products. Most of the mould cavity is blind and henceforth difficult to finish. In this study, a novel magnetorheological fluid-based finishing process using permanent magnet tools has been developed for nano-finishing of cylindrical blind hole surfaces. Tools to finish the internal and flat-bottomed surfaces of the cylindrical blind hole are developed. The finishing performance of both tools is evaluated for finishing ferromagnetic material used in dies. The material of the die is P20 tool steel having 41 HRC hardness. Response surface methodology using a central composite design technique has been utilized for the plan of experiments and analysis of significant process parameters on the percentage change in surface roughness using newly developed tools. During finishing the internal cylindrical blind hole surface, the process parameters like rotational speed, reciprocation speed and abrasive mesh size are found to be significant. However, during flat-bottomed surface finishing of cylindrical blind hole workpiece, rotational speed, abrasive mesh size and abrasives volume percentage are found to process significant parameters. Experimentation at optimized parameters results in the final surface finish of 83 nm on internal cylindrical surface and 93 nm on the flat-bottomed surface of cylindrical blind hole workpiece.

Investigation of magnetorheological fluid-based finishing process for improving the functional performance of hydraulic cylinder

“…Beyond these values of T r and W r, the % Δ Ra starts decreasing because the access increment in their values causes less time for AAPs to get into interaction with asperity peaks of the finishing workpiece surface. 34 Also, the enhanced speed of T r on an oppositely rotating workpiece with excessively enhanced W r makes the EIPs unstable because of the dominating centrifugal force ( F c n) on the indenting magnetic force ( F m r normal_ i n) (Figure 2), because of which the loosely gripped AAPs perform poor finishing action. Therefore, the % Δ Ra trend is observed decreasing beyond the T r = 400 r/min and W r = 30 r/min.…”

Magnetic field-assisted finishing processes: from bibliometric analysis to future trends

“…The development of new and more efficient auxiliary tools (e.g., magnetic abrasives, abrasive particles, and fluid) can shorten processing time, increase MRR, and provide even lower tolerances for machined components. Other possible solutions include new magnetic field configurations, such as multi-magnetic poles [ 74 – 76 ], new methods [ 77 – 79 ] or new tool configurations [ 80 – 88 ], and improvements in magnetic tools (combination of aggressive polishing and then lower MRR as the process continues [ 89 ] or fixed/loose-abrasive configuration [ 57 , 58 ]).…”

Analysis on machining uniformity in reciprocating magnetorheological polishing based on abrasive particle trajectory

“…Therefore, MRP is considered to be one of the most promising intelligent polishing methods in the future. Nowadays, some scholars and researchers are devoted to the research on the MRP methods, such as MRP with roller (Song et al , 2018), ball-end MRP (Khan and Jha, 2019; Alam and Jha, 2017), rotary magnetorheological honing (Paswan and Singh, 2021; Sirwal et al , 2020) and cluster magnetorheological plane polishing (Pan and Yan, 2015; Yan et al , 2010).…”