Determining dynamically active abrasive particles in the media used in centrifugal force assisted abrasive flow machining process

Abrasive flow machining (AFM) is a relatively new non-traditional process in which a semisolid media consisting of abrasive particles and a flexible polymer carrier is extruded through or across the component to be machine finished. This process is capable of providing excellent surface finishes on a wide range of simple as well as intricated shaped components. Low material removal rate happens to be one major limitation of this process, because during machining not all the abrasive particles participate in removing material from the work piece. Limited efforts have hitherto been directed towards improving the efficiency of the process so as to achieve higher material removal rates. An effort has been made towards the performance improvement of this process by applying centrifugal force on the abrasive media with the use of a rotating centrifugal force generating (CFG) rod introduced in the work piece passage. The modified process is termed as centrifugal force assisted abrasive flow machining (CFAAFM). This paper presents a mathematical model developed to calculate the number of dynamics active abrasive particles participating in the finishing operation in the AFM and CFAAFM process. The analysis of results show that there is great enhancement of number of dynamic active abrasive particles in CFAAFM as compared to the AFM process, which seems to be the contributing factor for the increase in material removal and % improvement in surface roughness for a given number of cycles in CFAAFM. The results of experiments conducted to validate the model show a close agreement between the analytical and experimental results.