摘要
Zinc(Zn)has recently been recognized as a promising bone repair material due to its inherent biodegradability and favorable biocompatibility.In this work,rare earth neodymium(Nd)was introduced into a Zn-based alloy fabricated using a laser powder bed fusion(LPBF)process.Results showed that addition of Nd significantly improved the melt fluidity and reduced the evaporation of Zn,thereby achieving parts with a high densification rate of 98.71%.Significantly,the Nd alloying treatment effectively refined the grain size from 25.3 to 6.2μm.Nd Zn5 eutectics precipitated and contributed to a second-phase strengthening effect.As a result,the tensile strength increased to(119.3±5.1)MPa and the Vickers hardness to(76.2±4.1).Moreover,the Zn–Nd alloy exhibited good anti-inflammatory activity,as the Nd ions released during degradation had a strong affinity with cell membrane phospholipids and consequently inhibited the release of inflammatory cytokines.It also presented favorable cytocompatibility,showing great potential as a bone repair material.
目的:锌具有良好的降解性能和生物相容性,被视为一种很有前途的骨修复材料。然而,锌金属作为骨植入物时的力学强度难以满足承重骨修复的需求,并存在炎症反应的风险。本文旨在探讨稀土钕合金化对锌骨植入物激光成形质量的影响,为改善锌合金的成形质量、提高力学性能及增加抗炎活性提供理论依据。创新点:1.在增材制造过程中,添加钕能够有效改善锌基合金的成形质量;2.稀土钕提高了锌基合金的力学性能,同时也赋予了抗炎活性。方法:1.通过实验对比锌钕合金的表面形貌,计算出相应的致密度,并分析钕对锌基合金成形质量的影响(图2);2.基于不同实验对比锌钕合金的微观组织结构及力学强度的变化,并探讨稀土钕提高力学性能的原因(图3~5和表1);3.通过电化学实验和浸泡实验,分析稀土钕对降解性能的影响(图6和7);4.基于体外生物学实验,对比分析钕对抗炎活性和细胞活性的影响(图8和9)。结论:1.稀土钕提高了激光增材制造锌合金的成形质量,并使其致密化率高达98.71%;2.钕合金化有助于晶粒细化和第二相强化,使极限抗拉强度提高到了(119.3±5.1)MPa;3.钕合金化能抑制促炎因子的释放,促进抗炎因子的释放,进而使锌钕部分具有良好的抗炎活性,而细胞培养试验也表明其具有良好的生物相容性。
基金
the National Natural Science Foundation of China(Nos.51935014,82072084,and 81871498)
the Jiangxi Provincial Natural Science Foundation of China(Nos.20192ACB20005 and 2020ACB214004)
the Jiangxi Provincial Key R&D Program(No.20201BBE51012)
the Guangdong Provincial Higher Vocational Colleges&Schools Pearl River Scholar Funded Scheme(2018)
the China Postdoctoral Science Foundation(No.2020M682114)
the Open Research Fund of Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology
the Project of Hunan Provincial Science and Technology Plan(No.2017RS3008),China。
