(重慶大學(xué) 材料科學(xué)與工程學(xué)院，重慶 400045)
摘 要: 考察純鎂浸泡于模擬體液(SBF)中所發(fā)生的化學(xué)和物理過(guò)程，實(shí)驗(yàn)材料為擴(kuò)散退火態(tài)，浸泡時(shí)間3~21 d。結(jié)果發(fā)現(xiàn)，鎂的腐蝕速率隨時(shí)間增加而降低，同時(shí)溶液pH遞增；裂紋和腐蝕坑是材料損傷的主要形貌特征，而MgCl2的局部富積是形成腐蝕坑的重要原因；隨著浸泡時(shí)間延長(zhǎng)，Mg(OH)2沉積于試樣表面并逐步增長(zhǎng)，成為Ca、P在Mg表面沉積的屏障，因此抑制Mg(OH)2的形成和生長(zhǎng)是誘導(dǎo)磷酸鈣陶瓷在Mg表面沉積的必要條件。
關(guān)鍵字: 純鎂；模擬體液；腐蝕；Mg(OH)2；羥基磷灰石
（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
