Personalized Artificial Tibia Bone Structure Design and Processing Based on Laser Powder Bed Fusion

Abstract

Bone defects caused by bone diseases and bone trauma need to be implanted or replaced by surgery. Therefore, it is of great significance to design and prepare a tibial implant with good biocompatibility and excellent comprehensive mechanical properties. In this paper, with 316L stainless steel powder as the main material, a personalized artificial tibia design and processing method based on laser powder bed fusion is proposed. Firstly, the personalized model of the damaged part of the patient is reconstructed. Then, the porous structure of human tibia is manufactured by selective laser melting technology. To research the factors affecting the quality of selective laser melting porous structure, a laser heat source model, heat transfer model and molten pool model of laser powder bed fusion process were constructed; then, by changing the laser process parameters (laser power, laser beam diameter, scanning speed, powder layer thickness, etc.) to conduct multiple sets of simulation experiments, it is obtained that when the “laser power is 180 W, the laser scanning speed is 1000 mm/s, the laser beam diameter is 80 μm, the powder layer thickness is 50 μm”, the porous stainless steel parts with better quality can be obtained. Finally, the porous structure was fabricated by selective laser processing, and its properties were tested and analyzed. The experimental results show that the cell side length of cube is 1.2 mm, the elastic modulus of octahedral porous structure with pillar diameter of 0.35 mm is about 17.88 GPa, which match well with tibial bone tissue.

The Potential of Duplex Stainless Steel Processed by Laser Powder Bed Fusion for Biomedical Applications: A Review

“…The laser powder bed fusion (L-PBF) technology, in particular, is highly suitable for biomedical applications such as pre-surgical planning, prosthetics, and bone scaffolds for tissue engineering [22], given the high level of detail and the accuracy typical of this laser-based AM technology. L-PBF technology can effectively control the pore size, distribution, and porosity level of porous bone implants, allowing patient customization [23]. Stainless steel was among the first metals to be used in L-PBF processes, and today several biocompatible stainless steel alloys fabricated by L-PBF, such as 304 or 316 L, are readily available on the market [23,24].…”

“…L-PBF technology can effectively control the pore size, distribution, and porosity level of porous bone implants, allowing patient customization [23]. Stainless steel was among the first metals to be used in L-PBF processes, and today several biocompatible stainless steel alloys fabricated by L-PBF, such as 304 or 316 L, are readily available on the market [23,24]. Laser re-melting during the L-PBF process allowed for the achievement of a relative density of stainless steel devices of over 99.9%.…”