摘要
利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱仪(EDS)、腐蚀失重实验以及电化学工作站研究了退火处理对高压扭转变形(HPT)ZXJ310合金的微观组织和体外降解性能的影响。结果表明:高压扭转态ZXJ310镁合金在150℃退火时,随着退火时间延长(0~4 h),合金的平均晶粒尺寸由高压扭转态的98.3 nm,分别增长至169.8,217.6,220.2和259.5 nm。通过TEM观察可知,ZXJ310镁合金中的位错密度明显降低;电化学测试显示:随着退火时间延长,腐蚀电位明显增加,ZXJ310镁合金Nyquist图谱中的容抗弧半径逐渐增加,退火4 h后高压扭转ZXJ310镁合金的电化学腐蚀速率可以降低至0.32 mm·y^(-1);ZXJ310镁合金在模拟体液中的浸泡失重试验结果也表现出同样的趋势,3~4 h退火后的ZXJ310镁合金的耐蚀性显著提升;对ZXJ310镁合金的腐蚀产物分析可知,退火处理显著改善合金在模拟体液(SBF)溶液中的浸泡腐蚀行为,增加腐蚀产物膜层的致密性和稳定性,但不会对合金腐蚀产物的类型产生影响。不同状态下ZXJ310镁合金在相同浸泡条件下产生的腐蚀产物种类没有区别,浸泡120 h后均能产生含羟基磷灰石的Ca-P化合物。
In recent years,the degradable metals represented by magnesium and magnesium alloys have gradually become a research hotspot for fracture internal fixation and bone defect repair materials due to their good biocompatibility,suitable elastic modulus and degradable characteristics,and are a type of medical metal materials with great application potential.ZXJ310 magnesium alloy has the characteristics of full nutrient composition,but it is found that the alloy still has the problems of non-uniform corrosion,high corrosion rate and serious gas production.The use of severe plastic deformation(SPD) process can refine the grains,thereby increasing the strength of the alloy and improving the corrosion resistance,and the application of the large plastic deformation process to magnesium and magnesium alloy processing has improved its potential for biomedical applications.Commonly used methods include equal channel angular pressing(ECAP) and high pressure torsion(HPT).HPT is more suitable for the metal materials with close-packed hexagonal structure that are difficult to deform,and HPT can significantly reduce the grain size of magnesium alloys,and some scientists have shown that the distribution and number of the second phase will be improved during the high-pressure torsional process,which can help improve the corrosion resistance of the alloy.In the early stage,a bulk ZXJ310 alloy with nanocrystalline characteristics was successfully prepared by exploring HPT parameters,with a good second phase dispersion distribution state.HPT was carried out at room temperature using the HPT-4 high-pressure torsion equipment manufactured by TRANSMST,Austria in this study,and the specimen size was Ф10 mm×1.0 mm.According to the preliminary process study,the torsion cycle was set to 15 cycles,the test pressure was 7.85 GPa,and the rotational speed was set to 1 r·min~(-1).There were high residual stresses and crystal defects in the processing process of HPT alloy,such as high-density dislocations,and it was necessary to combine the low
作者
张家振
马鸣龙
李永军
孙昭乾
史文鹏
郝雪龙
张奎
Zhang Jiazhen;Ma Minglong;Li Yongjun;Sun Zhaoqian;Shi Wenpeng;Hao Xuelong;Zhang Kui(State Key Laboratory of Nonferrous Metals and Processes,China GRINM Co.,Ltd.,Beijing 100088,China;GRIMAT Engineering Institute Co.,Ltd.,Beijing 101407,China;General Research Institute for Nonferrous Met-als,Beijing 100088,China;National Analysis and Testing Center for Non-Ferrous Metals and Electronic Materi-als,National Standard(Beijing)Inspection and Certification Co.,Ltd.,Beijing,101407,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2024年第5期609-617,共9页
Chinese Journal of Rare Metals
基金
国家重点研发计划项目(2021YFB3701002)资助。
