INVESTIGATION OF HYBRID ELECTROCHEMICAL AND MAGNETIC FIELD ASSISTED ABRASIVE FLOW FINISHING PROCESS

Abstract

The current scenario of industrialization requires need for higher productivity which is met by advanced material removal process, i.e., abrasive flow machining (AFM) in which the internal surfaces of the workpiece is machined to higher accuracy level with the help of abrasive laden media. In this paper, the conventional AFM setup has been made hybrid using electrolytic and magnetic force arrangement alongwith rotational effect in order to achieve better results in terms of material removal and surface roughness. The newly developed in-house polymer media were utilized in the process and the input parameters taken during experimentation were magnetic flux, electrolytic rod size and shape, rotational speed, polymer media, abrasive particles and extrusion pressure. It was found that the material removal and surface roughness improvement were more in electrochemo magneto rotational AFM process compared to conventional AFM process. The experimental values were in confirmation with those obtained in the optimization techniques applied, i.e., Taguchi L9 OA, Matlab fuzzy logic and GRA-PCA. In addition, the hybrid mathematical model was developed and effect of different forces occurring in the process and computational flow analysis of media have been explained. With advent of need for fast productivity in terms of material removal and surface roughness of the workpiece, abrasive flow machining (AFM) process is gaining rapid importance in the industries. In this process, the fine finishing of the internal surfaces is done that are difficult to reach spaces using abrasive laden polymer media. The media is extruded past the surface under high pressure with the help of two sets of extrusion piston cylinder arrangements. Further various innovations done in the field of abrasive flow machining have been studied in detail in a tabulated form. It included the applications of the process and the different variant forms of AFM process. Hence it can be concluded that this form of non conventional machining process is efficient both in terms of surface roughness and material removal. The SBR media resulted in maximum material removal during experimentation, i.e., 3.88 mg when input parameters, i.e., electrolytic voltage, number of extrusion cycles and pressure were taken as 18 V, 4 and 10 bar respectively. The NR, NTR and SR media had intermediate effect of material removal but minimum removal of material was achieved in case of PBS media, i.e., 2.39 mg at 6 V voltage, 6 number of cycles and 30 bar pressure. The material removal was first increased with higher rod size but afterwards its increase was lesser. The surface plots obtained from RSM technique showed that MR obtained was 2.25 mg at 21 bar pressure and 7 number of cycles. As compared to conventional AFM setup, it was found that in EMR-AFM setup, 34.5 % and 17.8 % improvement in % Ra and material removal, respectively, was obtained. It was found that MR was approximately 2.9 mg on an average when machining was done on traditional AFM process, while it increased upto 4.5 mg in prepared hybrid machine setup.