Development and characterization of fly ash-ground tire rubber-based abrasive flow finishing media and its performance assessment

The study aims to develop a novel, fly ash-ground tire rubber media for abrasive flow finishing (AFF) applications by utilizing by-products or waste materials. The novel media was characterized through rheological, thermal, and mechanical tests. Compared to conventional silicon carbide (SiC)–styrene butadiene media, the developed media is thermally stable and elastically dominant, suggesting the existence of a high-magnitude pseudo-network in the fly ash-ground tire rubber media. The developed media demonstrates a 72% improvement in surface roughness (Ra) for aluminum (Al) workpieces and a 48% improvement for EN-8 workpieces. Scanning electron microscopy, optical profilometry, and energy-dispersive X-ray analysis of the polished workpiece surface confirm the enhanced surface quality and the potential of fly ash-ground tire rubber media in finishing applications. Fly ash-ground tire rubber media produces an excellent surface finish of 0.21 and 0.23 μm for Al and EN-8 workpieces, respectively. The performance of the novel media increases with fly ash loading; however, excessive fly ash abrasive loading in the media can cause a substantial increase in media viscosity, leading to significant abrasion marks on the polished workpiece surface, especially in the case of relatively less hard materials. This study presents a viable and cost-effective alternative media for AFF applications, opening new avenues for utilizing fly ash as an affordable abrasive and ground tire rubber as media.