ABRASIVE FLOW FINISHING OF FDM PRINTED EXTRUSION DIE INSERT PATTERN USING NOVEL AFM FIXTURE WITH MANDREL GUIDE

The staircase/stair-stepping effect causes wrapping, shrinkage, and surface roughness in additively manufactured (AM) parts. Consequently, abrasive flow finishing (AFF) or abrasive flow machining (AFM) may be employed to improve the AM part surface finish. This study developed an environmentally friendly AFM media using rice husk ash as base material, waste vegetable oil as a liquid synthesizer, and natural additives, i.e. glycerin. The new newly developed rice husk ash-based AFM media (HSAFM) characterization was done using Fourier Transform Infrared (FTIR) spectroscopic method and thermogravimetric analysis (TGA). AFM medium viscosity was optimized using a Taguchi design ([Formula: see text]). These FDM-printed extrusions die inserts were finished using optimized AFM media in a one-way AFM system. A new AFM fixture with a mandrel guide was developed to direct media flow inside the die cavity to ensure uniform finishing. Experimental research has been done on finishing the FDM-printed extrusion die insert pattern using the Box–Behnken Design (BBD)-based experimental design of the response surface methodology (RSM) technique. The surface roughness Ra [Formula: see text]28.16 [Formula: see text]m was improved by 96% with the following process parameters: media viscosity of 60 Pa/s, the layer thickness of 0.3, and 90 min of finishing time.