Sustainable multiphase jet polishing of additively manufactured heat pipes utilizing recycled glass chips

Abstract

Each year, a huge amount of waste glass chips is produced by machining, which is not recycled and has been treated as waste, resulting in the wasting of resources. However, the pristine physical properties of these micro-sized chips show great potential to be recycled as abrasives in jet polishing. In this work, machined glass chips were recycled and directly used as the abrasives in multiphase jet (MPJ) and abrasive water jet (AWJ) polishing for aluminum heat pipes of additive manufacturing with complex structures. Polishing performance of the recycled abrasives from waste glass was compared with those of commercial quartz abrasives with mesh sizes of 600, 800, 1000, 1200, and 3000. The results show that the recycled abrasives of glass chips have comparable performance to the commercial abrasives with mesh size of 1000. Computational fluid dynamic simulations were conducted on the two jet polishing to elucidate the fundamental material removal mechanisms. It is found that a higher drag force in the AWJ polishing could lead to uniform material removal and induce four times higher for material removal rate (MRR). The cost of setup, water and energy consumptions of MPJ polishing are only one tenth those of AWJ polishing. Energy dispersive spectroscopy reveals that there is no element contamination on the polished surface. This work proposes a novel approach of MPJ polishing for components produced by additive manufacturing with complicated structures. These findings provide new insights for the recycling use of waste chips generated in manufacturing, and suggest new solutions for saving energy and resources, as well as for clean and green production.