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.

通过增材制造技术（如3D打印）生产的结构元件日益受到青睐。这一趋势得益于该技术的多功能性以及以低成本生产复杂形状元件的可能性。得益于增材技术，光学元件如透镜的打印成为可能。[1] 目前，FDM（熔融沉积建模）打印技术最为广泛使用，但采用紫外线固化树脂的技术正逐渐受到更多关注。[2] 由于其简捷性与高效性，DLP（数字光处理）技术在发展速度上尤为突出，该技术通过LCD显示屏硬化生产物体的整个横截面。本文探讨了使用DLP和FDM方法生产的3种不同材料的摩擦学特性测试结果。确定了摩擦系数w与单位压力以及磨损强度对金属、聚合物摩擦对的关系特性。在所述工作中，对由PA6、PLA、UV-R制成的聚合物元件在316L钢上摩擦，并伴有林格液存在的条件下进行了测试。测试在针-盘摩擦试验台上进行。测试材料是所述增材技术中最常用的。对确定的摩擦学特性的分析，可对上述材料用于生产植入物轴承和密封系统的适用性进行评估。测试的摩擦组合可用于生产复杂稳定系统元件（如动态髓内钉）[3]，以及未来的人工关节滑动节点。