摘要
Mg-Li based alloys hold much attention as potential biomedical materials due to their excellent ductility. A reduced mechanical strength and concern for biocompatibility are exhibited for Mg-Li binary alloys due to the presence of Li element. Addition of the Ca element into Mg-Li alloys leads to an improvement in mechanical strength and biocompatibility.In the present work, the microstructure, mechanical property and corrosion behaviors of three kinds（α, α＋β, β） of as-extruded Mg-Li（1, 9 and 15 wt.%）-1 Ca alloys were investigated using optical microscope, X-ray diffraction（XRD）, tensile,immersion and electrochemical polarization measurements.In vitro biocompatibility was evaluated by cytotoxicity assays,hemolysis and four coagluation tests. The results indicated that the Mg-1 Li-1 Ca and Mg-15 Li-1 Ca alloys were characterized by α-Mg and β-Li phases besides Mg2 Ca particles, respectively; while the Mg-9 Li-1 Ca by dual（α-Mg＋β-Li） phase together with Mg2 Ca phase. The Mg-1 Li-1 Ca alloy had the highest ultimate tensile strength（UTS） and yield strength（YS）and the lowest elongation（EL） to failure（10.1±1.24%） as well.The EL for the Mg-9 Li-1 Ca alloy was the highest（52.2±0.01%）.The long-term immersion tests revealed a decrease in corrosion resistance with increasing Li content. The results of cytotoxicity assays clearly showed that the Mg-Li-Ca alloys demonstrated no toxicity to L-929 cells in 10% concentration of extracts. The Mg-1 Li-1 Ca alloy also exhibited an acceptable hemolysis ratio. The results of four coagulation tests designated no sign of thrombogenicity for the Mg-Li-Ca alloys except for the Mg-15 Li-1 Ca alloy.
基于良好的延展性,Mg-Li基合金作为潜在的生物材料,引起了大家的广泛注意.由于锂元素的存在,Mg-Li二元合金表现出较低的机械强度与人们对其生物相容性的担忧.而在Mg-Li合金中添加钙元素则有利于提高其机械强度与生物相容性.本文中,通过光学显微镜、X射线衍射、拉力拉伸、浸泡实验以及电化学极化测试等综合评估了三种类型(α,α+β,β)的挤压态Mg-Li(1,9以及15 wt.%)-1Ca合金的微观结构、力学性能以及腐蚀行为.体外生物相容性通过细胞毒性、溶血以及凝血四项表征.结果表明,Mg-1Li-1Ca和Mg-15Li-1Ca合金分别由α-Mg、β-Li以及Mg_2Ca相构成;而Mg-9Li-1Ca则由α-Mg、β-Li双相以及Mg_2Ca相构成.Mg-1Li-1Ca合金表现出最高的最大抗拉强度和屈服强度,但其延伸率最低,仅为10.1±1.24%;Mg-9Li-1Ca合金的延伸率最高,为52.2±0.01%.长时间浸泡实验表明,随着锂元素含量的增加,合金的耐蚀性逐渐降低.毒性试验结果表明,在10%浸提液中Mg-Li-Ca合金对L-929细胞无明显毒性反应.Mg-1Li-1Ca表现出人体可以接受的溶血率.凝血四项实验结果指出,除Mg-15Li-1Ca外,Mg-1Li-1Ca和Mg-9Li-1Ca合金无促凝性反应产生.
作者
Lanyue Cui
Lu Sun
Rongchang Zeng
Yufeng Zheng
Shuoqi Li
崔蓝月;孙麓;曾荣昌;郑玉峰;李硕琦(College of Materials Science and Engineering, Shandong University of Science and Technology;State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology;Department of Materials Science and Engineering, College of Engineering, Peking University)
基金
supported by the National Natural Science Foundation of China (51571134)
the Scientific Research Foundation of Shandong University of Science and Technology (SDUST) for Recruited Talents (2013RCJJ006)
SDUST Research Fund (2014TDJH104)
Joint Innovative Center for Safe and Effective Mining Technology and Equipment of Coal Resources
