Laser based additive manufacturing of UHMWPE offers new opportunities for realizing complex components for medical implants. Conventionally, laser powder bed fusion of UHMWPE is achieved by CO₂ lasers but up to now the mechanical properties of the produced specimen are still relatively poor. The aim of the presented work is to extend the processing window for this material to improve the physical properties by using ultrashort laser pulses at a wavelength of 1030 nm. The linear absorption of UHMWPE at 1030 nm is extremely low, which prevents the use of common continuous solid-state lasers. By contrast, the 500 fs laser pulses used result in peak intensities of several hundred GW/cm² leading to multi-photon absorption processes. We show that the absorption can be locally increased up to 20 %. Hence, it was possible to deposit and accumulate enough heat to fuse the polymer particles by controlling pulse energy and repetition rate. A suitable processing regime for sintering and complete melting has been investigated and correlated with the crystallinity and micro-hardness, reaching values similar to molded UHMWPE. Finally, preliminary tensile tests on produced specimens reveal an ultimate tensile strength of 4 MPa, surpassing the values obtained using a CO₂ laser.

基于激光的 UHMWPE 增材制造为实现医疗植入物的复杂组件提供了新的机会。传统上，UHMWPE 的激光粉末床融合是通过 CO ₂激光器实现的，但到目前为止，所生产样品的机械性能仍然相对较差。所提出工作的目的是通过使用波长为 1030 nm 的超短激光脉冲来扩展这种材料的加工窗口，以改善物理性能。UHMWPE 在 1030 nm 处的线性吸收极低，这阻碍了普通连续固态激光器的使用。相比之下，使用的 500 fs 激光脉冲会产生数百 GW/cm ^{2 的}峰值强度导致多光子吸收过程。我们表明吸收可以局部增加高达 20  %。因此，可以通过控制脉冲能量和重复率来沉积和积累足够的热量来融合聚合物颗粒。已经研究了适合烧结和完全熔化的加工方式，并将其与结晶度和显微硬度相关联，达到类似于模制 UHMWPE 的值。最后，对生产的样品进行初步拉伸测试显示极限拉伸强度为 4 MPa，超过了使用 CO ₂激光获得的值。