Research on sodium bicarbonate abrasive jet machining technology for post-processing treatments of 3D printed PEEK implant to achieve non-destructive deburring and enhancing cell adhesion

The non-destructive deburring and hydrophilic surface machining of 3D printed Polyetheretherketone (PEEK) implants surface is critical for post-processing production of the implants. A green sodium bicarbonate abrasive jet machining technology was proposed in this study, aiming to ensure low damage of implants surface while effectively deburring and creating a hydrophilic surface conducive to cell adhesion. By comparing the machining effects of sodium bicarbonate abrasive and other hard abrasives (alumina and glass bead) under various jet pressures and angles, it was confirmed that sodium bicarbonate abrasive jet machining technology could provide the low damage (Ra=1.75∼3.73 μm), moderate machining rate (0.24∼2.26 mg/s), excellent deburring performance, and outstanding surface cleanliness. Based on the comparison of experimental data and finite element simulation results, the fluid characteristics of abrasive particle beam and the combined machining mechanism (compression and plowing effect) of sodium bicarbonate abrasive jet machining technology were determined. Based on the consistent crystal phase and high purity displayed in the characterization of recycled abrasives, the feasibility of the designed abrasive recycling procedure was confirmed. Moreover, the fluorescence staining results of the adherent cell proliferation experiments confirmed that the sodium bicarbonate abrasive jet machining technology could effectively promote cell adhesion and growth by providing the matte elongated scratch-like micro-texture for the PEEK implants surface. In the future, this technology could facilitate the development for post-processing treatments in 3D printed PEEK implants additive manufacturing process. • Sodium bicarbonate abrasive jet machining technology can deburr without damage. • Sodium bicarbonate abrasive jet machining technology provides high machining rate. • The machining mechanism is explored by FEM analysis. • The designed recycling procedure can solve the disposal problem of solid waste. • The enhancing effect on adhesion of adherent cells has been confirmed.