Self-modulating abrasive medium and its application to abrasive flow machining for finishing micro channel surfaces

This study developed a self-modulating abrasive medium whose viscosity and fluidity can be adjusted during the processing period. The complex micro channel was fabricated on the stainless steel (SUS304) by using wire electrical discharge machining (wire-EDM). An experiment of employing abrasive flow machining (AFM) was conducted to evaluate the characteristics of various levels of roughness and finishing of the micro channel surface. In the experiment, the parameters of affecting AFM machining including abrasive particle size, concentration, extrusion pressure and machining time were selected to verify the machining quality of the micro channel. Experimental results reveal that at high viscosity and concentration the surface roughness of a medium with a coarse particle size is lower than that of a medium with a fine particle size. Furthermore, the machining quality of the micro channel improves as the extrusion pressure and the machining time increase because there is an increase in the fluidity of the medium. Therefore, the self-modulating abrasive-laden medium can be used to determine and influence the surface finishing and the precision of the shapes.