Li Qian, Li Qiang, Lu Shasha, Pan Deng
School of Mechanical Engineering, University of Shanghai for Science & Technology, No. 516 Jungong Road, Shanghai 200093, China.
Materials Genome Institute, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
Nanomaterials (Basel). 2023 Dec 11;13(24):3113. doi: 10.3390/nano13243113.
Ti-6Al-4V alloy is widely used as a biomaterial for hard tissue replacement, but its Young's modulus is still higher than that of human bone tissue, which may cause a "stress shielding" effect and lead to implant loosening. In addition, metal implants with low magnetic susceptibility are beneficial for obtaining minimal artifacts in magnetic resonance imaging. To reduce Young's modulus and magnetic susceptibility of Ti-6Al-4V alloy, a series of irregular prismatic porous structure models were designed based on the Voronoi principle, built by changing the irregularity, prism-diameter-to-initial-seed-spacing ratio, and seed number, and studied using finite-element analysis. Porous samples were prepared by selective laser melting and subjected to a compression test and magnetic susceptibility test. The simulation results show that the prism-diameter-to-initial-seed-spacing ratio has the greatest impact on porosity compared with the irregularity and seed number. The simulation-predicted porosity and compression modulus are highly consistent with the measured ones. The irregular prismatic porous Ti-6Al-4V samples exhibit mechanical properties similar to those of human bones and show a magnetic susceptibility of no more than 50% that of compact Ti-6Al-4V. A regulatable irregular prismatic porous structure is feasible for designing porous implants with desirable properties for biomedical applications.
Ti-6Al-4V合金作为硬组织替代生物材料被广泛应用，但其杨氏模量仍高于人体骨组织，这可能会导致“应力屏蔽”效应并致使植入物松动。此外，低磁化率的金属植入物有利于在磁共振成像中获得最小伪影。为降低Ti-6Al-4V合金的杨氏模量和磁化率，基于Voronoi原理设计了一系列不规则棱柱形多孔结构模型，通过改变不规则度、棱柱直径与初始种子间距比以及种子数量来构建这些模型，并使用有限元分析进行研究。通过选择性激光熔化制备多孔样品，并进行压缩试验和磁化率试验。模拟结果表明，与不规则度和种子数量相比，棱柱直径与初始种子间距比对孔隙率的影响最大。模拟预测的孔隙率和压缩模量与实测值高度一致。不规则棱柱形多孔Ti-6Al-4V样品表现出与人体骨骼相似的力学性能，并且磁化率不超过致密Ti-6Al-4V的50%。对于设计具有理想性能的生物医学应用多孔植入物而言，可调节的不规则棱柱形多孔结构是可行的。
