A novel thermal analysis of the abrasive flow machining (AFM) process

Rising media temperature during abrasive flow machining (AFM) is known to degrade material removal rate. Ironically, little is known with regard to heat generation, heat transfer, and its relationship to media flow during typical process conditions. This paper presents a multi-physics simulation model of the AFM process that predicts the interactions between heat generation, heat transfer, media temperature, and media flow. Predictions of local pressure and temperature within a flow channel showed very good agreement with measurements derived from AFM experiments. Using this model, it was determined for the executed AFM experiments that (1) minor flow disruptions in the working flow channel resulted in significant differences in local heat generation and local media temperature, (2) heat generation due to media shearing is 30 to 42 times larger than that associated with metal chip formation, (3) 75% of the heat generated by media shearing occurred in the relatively small active machining zone as opposed to the relatively large media chambers, (4) the cooling rings surrounding the media chambers contribute to 88% of the heat extraction as opposed to 12% from ambient air convection through the external fixture surfaces, and (5) once media temperature starts to rise, the ability of the cooling rings to extract heat from media progressively diminishes due to increased media flow rate.