( 重慶大學(xué) 材料科學(xué)與工程學(xué)院， 重慶 400044)
摘 要: 對純度為99.9%的純鎂表面改性， 以提高純鎂在仿生模擬體液（SBF）中的耐腐蝕性能。 其過程為： 室溫下將純鎂在初始pH值為9.3的過飽和NaHCO3-MgCO3混合溶液中浸泡24 h， 然后在773 K保溫10 h； 再將試樣放入(37±0.5)℃的SBF 溶液中浸泡14 d。 X射線衍射分析表明: 純鎂在NaHCO3-MgCO3混合溶液中浸泡后，表層主要為MgCO3·3H2O晶體； 熱處理后， MgCO3·3H↓2O晶體轉(zhuǎn)變成MgCO3和Mg(OH)2的混合物。 EDS分析表明, 距表面厚約20 μm的基體被氧化， 形成了耐蝕氧化層。 經(jīng)堿熱處理的試樣在SBF溶液中浸泡14 d后， 經(jīng)X熒光能譜（XPF）分析可知表層沉積出Ca/P摩爾比為1.858的鈣磷基沉淀。 本階段實(shí)驗(yàn)表明, 堿熱處理可以顯著提高純鎂在仿生環(huán)境下的耐腐蝕性能。
關(guān)鍵字: 鎂; 生物材料； 表面改性； 堿熱處理； SBF溶液
and its corrosion behaviors in SBF
（ College of Materials Science and Engineering,
Chongqing University, Chongqing 400044, China）
Abstract: The surface modification on magnesium(99.9%) was carried out to improve its corrosion resistance in simulated body fluid(SBF) solution. Pure magnesium specimens were first treated in supersaturated NaHCO3-MgCO3 mixed solutions(SNSM) at room temperature, and then heat-treated at 773 K for 10 h; finally, the corrosion resistance of the samples was tested in SBF solution. The X-ray diffraction(XRD) analysis shows that the coatings obtained on the samples after being treated in SNSM solution is mainly composed of MgCO3·3H2O. More important, EDS analysis shows that a magnesium oxide layer with thickness of 20 μm is formed after heat treatment. Ca-P based depositions with molar ratio of 1.858 are detected on the modified specimens after they are immersed in SBF for 14 days. It can be concluded that the coating obtained through alkali and heat treatment could effectively protect magnesium from corrosion in the simulated biological environment.
Key words: magnesium； biomaterials; surface modification; alkali-heat-treatment; SBF solution
