Enhancing AFM process productivity through improved fixturing

Abstract

Abrasive flow machining (AFM) is a nonconventional finishing process that deburrs and polishes by forcing an abrasive laden media across the workpiece surface. The process embraces a wide range of applications from critical aerospace and medical components to highproduction volumes of parts. One serious limitation of this process is its low productivity in terms of rate of improvement in surface roughness. Limited efforts have hitherto been directed towards enhancing the productivity of this process with regard to better quality of workpiece surface. This paper discusses improved fixturing as a technique for productivity enhancement in terms of surface roughness (R a ). A rotating centrifugal-force-generating (CFG) rod is used inside the cylindrical workpiece which provides the centrifugal force to the abrasive particles normal to the axis of workpiece. The effect of the key parameters on the performance of process has been studied. The results shows that for a given improvement in R a value, the processing time can be reduced by as much as 70-80%. It is seen that the significant process parameters are revolutions per minute of CFG rod, extrusion pressure and abrasive mesh size.

Abrasive Flow Machining: An Area Seeking for Improvement

“…It is also observed that the pressure decreases with increase in length of media flow travel. In AFM, it has been reported that enhancement in performance could be achieved by improved fixturing [27]. The machining parameters, such as concentration, mesh number and number of cycles were changed to determine their effects on the machining characteristics material removal (MR) and enhancement in surface finish in PEC Chandigarh [29].…”

Electrochemical-aided abrasive flow machining (ECA2FM) process: a hybrid machining process

“…A work-piece is a hollow cylindrical piece made up of yellow brass (65 % Cu, 35 % Zinc, 156 BHN hardness) and had been selected based on literature review [1,[5][6][7][8], past optimization of the developed basic AFM setup [26] and pilot experimentation [22,23] (refer to Fig. 3).…”

“…A fine finished part has better aesthetics, life, and functional performance due to its high polish, close dimensional controls and strength endurance. Finishing operations are labour intensive, least controllable and cost approximately 15 % of the total machining cost in the manufacture of precision parts [1]. The traditional finishing methods of grinding, lapping, honing and super finishing are good for the simple surface geometries but are found lacking in the fine finishing of intricate/hard surfaces.…”

“…The magnetic action was attained by mixing the polymer base with ferromagnetic material, resulting in the desired rheology of the abrasive laden media along with magnetic forces on the iron particles. Walia et al developed centrifugal force-assisted AFM (CFAAFM) process by simultaneously rotating the extruding AFM media employing different shaped rods and observed intensive abrasive action [1,[6][7][8][9]. Singh and Walia further optimized the various parameters to achieve polished surfaces [10].…”

Numerical simulation analysis of valve spool double-nozzle with abrasive flow

“…Compared with the traditional machining method, the abrasive flow polishing technology can use the abrasive media flow to the complex structure of the hole and cavity deep hole polishing processing, but also according to the application requirements of parts, selecting different abrasive media to polish the parts, so as to obtain different polishing effect to meet the requirements of parts, abrasive flow processing principle shown in Fig. 1 [6][7][8][9][10].…”