摘要
基于Mg-4Zn-0.2Mn-0.2Ca合金优良的生物兼容性,利用此挤压态合金开发可降解骨板材料。利用Hank’s模拟溶液长期体外浸泡以及弯曲试验对骨板材料的降解性能以及力学性能进行评估。试验结果表明,该骨板降解速率在浸泡第7天时达到最高值,然后随着浸泡时间的延长而降低,浸泡90天后达到稳定(约0.84 mm/a)。同时,经过60天的浸泡,其抗弯强度仍保持在67.6 MPa,说明骨板在长期降解后仍能承受力学载荷。在微电偶作用下,连续分布的第二相与基体分离,形成点蚀坑,最终在表面腐蚀坑的作用下,合金力学性能降低。
An extruded Mg-4Zn-0.2Mn-0.2Ca alloy was developed as potential biodegradable bone-plate due to its excellent biocompatibility.Long term in vitro immersion in Hank’s solution and bending test were used to evaluate the degradability and the mechanical integrity of the alloy.The results revealed that the degradation rate of the bone-plate increased in the first 7 days and then decreased with the prolonged immersion time before it finally reached a steady stage(about 0.84 mm/a)after immersion for 90 days.The bending strength after immersion for 60 days was 67.6 MPa,indicating that the bone-plate could support certain mechanical load after long term degradation.The formation of corrosion pits after degradation stemmed from the separation of the continuously distributed second phases from Mg matrix under the action of micro-galvanic couples.As a result,the mechanical performance of Mg-4Zn-0.2Mn-0.2Ca alloy was aggravated owing to the corrosion holes on its surface.
作者
程元芬
杜文博
刘轲
付军健
王朝辉
李淑波
付金龙
Yuan-fen CHENG;Wen-bo DU;Ke LIU;Jun-jian FU;Zhao-hui WANG;Shu-bo LI;Jin-long FU(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China)
基金
Projects(2016YFB0301001,2016YFB0301101)supported by the National Key Research and Development Program of China
Project(51801004)supported by the National Natural Science Foundation of China
Project(KM201710005005)supported by Beijing Municipal Education Commission,China
Projects(2172013,2192006)supported by Beijing Natural Science Foundation,China
关键词
镁合金
抗弯强度
腐蚀行为
体外降解
骨板
magnesium alloys
bending strength
corrosion behaviors
in vitro degradation
bone-plate