(重庆大学 材料科学与工程学院，重庆 400045)
摘 要: 考察纯镁浸泡于模拟体液(SBF)中所发生的化学和物理过程，实验材料为扩散退火态，浸泡时间3~21 d。结果发现，镁的腐蚀速率随时间增加而降低，同时溶液pH递增；裂纹和腐蚀坑是材料损伤的主要形貌特征，而MgCl2的局部富积是形成腐蚀坑的重要原因；随着浸泡时间延长，Mg(OH)2沉积于试样表面并逐步增长，成为Ca、P在Mg表面沉积的屏障，因此抑制Mg(OH)2的形成和生长是诱导磷酸钙陶瓷在Mg表面沉积的必要条件。
关键字: 纯镁；模拟体液；腐蚀；Mg(OH)2；羟基磷灰石
（College of Materials Science and Engineering, Chongqing University,Chongqing 400045, China）
Abstract: The chemical and physical processes of magnesium immersed in SBF were investigated. The samples were as-annealed; the immersion time was 3−21 d. The result shows that as the immersion time increases, the corrosion rate decreases while the SBF pH increases. Network-like cracks and pits are the main damages resulting from corrosion. The locally buildup of MgCl2 is the major cause of pitting. A Mg(OH)2 forms and gradually covers the sample surface. This layer acts as the barrier for the precipitation of Ca and P on the sample surface, thus it is crucial to depress the formation of Mg(OH)2 in order to have calcium phosphate bioceramics deposit on magnesium surface.
Key words: pure magnesium; simulated body fluid(SBF); corrosion; Mg(OH)2; hydroxyapatite
