Relation between materials, process, structure and property of metallic porous bone scaffolds fabricated by laser powder bed fusion (LPBF): a review

Abstract

Currently, bone defects have become one of the major problems in clinical treatment, and there is an urgent need to find an ideal artificial bone. The ideal artificial bone should have good biocompatibility, excellent bioactivity, appropriate porous structure, and mechanical properties similar to those of bone tissue. The emergence of additive manufacturing (AM) technology offers the possibility to achieve customization of bone implants. Laser powder bed fusion (LPBF), a type of additive manufacturing, is widely used for the fabrication of porous metal stents due to its high energy density and molding quality. In this paper, the whole process of LPBF in porous metal scaffolds is described in detail, the applications and prospects of different metal materials in porous scaffolds are introduced, the influence of porous scaffold structure on scaffold performance is analyzed, the importance of process parameter selection is discussed as well as the influence on the microstructure and quality of the porous scaffolds, and the commonly used post-processing methods and biocompatibility are summarized and discussed after LPBF, including heat treatment, thermal isostatic pressing and surface modification to improve the optimal performance of porous scaffolds. Finally, the prospect of the development of porous metal scaffolds prepared by LPBF is envisioned.