Tribological properties of the sliding components of implants manufactured by 3D printing (FDM and DLP)

The production of structural elements by means of additive techniques (3D printing) is becoming more and more popular. This is due to the versatility of these methods and the possibility of producing complex-shaped elements at low cost. Thanks to additive techniques, it is possible to print optical elements such as lenses [1]. Currently, FDM (Fused Deposition Modeling) printing is the most widespread, but techniques using UV radiation to cure resins are gaining more and more popularity [2]. Due to the simplicity and efficiency, the fastest growing is the DLP (Digital Light Processing) technology, consisting in hardening the entire cross-section of the produced body with the use of an LCD display. The paper presents the results of tribological tests of 3 different materials produced with the use of DLP and FDM methods. Characteristics of the dependence of the friction coefficient w on unit pressure and the wear intensity for pairs rubbing metal, polymer, were determined. As part of the described work, polymer components made of PA6, PLA, UV-R during friction on 316L steel in the presence of ringer fluid were tested. The tests were carried out on a pin-on-disc stand. The materials tested are the most commonly used in the described additive techniques. The analysis of the determined tribological characteristics allows for the assessment of the suitability of using the above-mentioned materials for the production of bearing and sealing systems for implants. The tested rubbing associations can be used, inter alia, for the production of elements of complex stabilization systems (dynamic intramedullary nails) [3], and in the future also for the sliding nodes of endoprosthesis. Bibliography: [1] Squires A.D., Constable E., Lewis R.A., 3D Printed Terahertz Diffraction Gratings And Lenses, J. Infrared, Millimeter, Terahertz Waves. 36 (2015), s.72–80. [2] Yao L., Hu P., Wu Z., Liu W., Lv Q., Nie Z., Zhengdi H., Comparison of accuracy and precision of various types of photo-curing printing technology, J. Phys. Conf. Ser. 1549 (2020). [3] Grygier D., Słowiński J., Kowalewski P.: Wydłużanie kości długich – metody i zastosowanie, Inżynier i Fizyk Medyczny, vol. 9, 6/2020, s. 458-460.