Additive manufacturing provides a novel and robust way to prepare medical product with anatomic matched geometry and tailored mechanical performance. In this study, the surface characteristics, microstructure, and mechanical properties of fused deposition modeling (FDM) prepared polyether-ether-ketone (PEEK) were systematically studied. During the FDM process, the crystal unit cell and thermal attribute of PEEK material remained unchanged, whereas the surface layer generally became more hydrophilic with an obvious reduction in surface hardness. Raster angle has a significant effect on the mechanical strength but not on the failure mechanism. In practice, FDM fabricated PEEK acted more like a laminate rather than a unified structure. Its main failure mechanism was correlated to the internal voids. The results show that horizontal infill orientation with 30° raster angle is promising for a better comprehensive mechanical performance, and the corresponding tensile, flexural, and shear strengths are (76.5 ± 1.4) MPa, (149.7 ± 3.0) MPa, and (55.5 ± 1.8) MPa, respectively. The findings of this study provide guidelines for FDM-PEEK to enable its realization in applications such as orthopedic implants.

Excessive wear is a key issue affecting the performance of ultra‐high molecular weight polyethylene (UHMWPE)‐based artificial prosthesis. This work is focussed on the bio‐tribology behaviours of UHMWPE when mating with different metal counterparts (iron‐based 316L, Co‐based Stellite‐S21 and Stellite‐S22). According to the ASTM F732 standard, two million cycles comparative wear tests were carried out under bovine serum lubrication. When coupled with S21, S22, and 316L metal counterparts, the obtained average wear factors of UHMWPE were 1.333 ± 0.192, 1.360 ± 0.160, and 1.190 ± 0.177 × 10−6 mm3/N · m, respectively. Initial surface roughness of the metal counterpart has shown an important role in controlling the volume of UHMWPE wear, especially the first one million cycles. Compared with 316L, CoCrMo‐based counterparts possessed relative higher hardness and exhibited less rise in surface roughness caused by wear. For UHMWPE‐on‐metal bearings, random scratch, surface pit, and wear debris attachment were commonly seen, which suggested the coexistence of abrasion, third‐body abrasion, and adhesion‐based wear. In contrast, the metal counterpart was slightly scratched with no polymer transfer film formation. The work conducted in the present study gives useful knowledge regarding the UHMWPE‐on‐metal bearing design. With an intention to minimise wear, surface roughness of metal counterpart should be carefully controlled.