二水磷酸氢钙包覆镁粉的组织及其在NaCl溶液中的腐蚀行为

摘要

Magnesium coated with calcium phosphate were produced via chemical liquid deposition method.The coating were analyzed by scanning electron microscope(SEM),energy dispersive spectrometer (EDS),X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FT-IR).Accelerated surface area and porosimetry system(ASAP-2020) was used to measure the specific surface area of different powders.The corrosion process of coated and uncoated powders were studied by immersion test.It was shown that the magnesium powder were coated with a layer of dicalcium phosphate dihydrate(DCPD) with thickness of 2-4 μm.The coated particles were spheric,similar to the raw magnesium particles.The specific surface area of coated powder increased by sixty times,compared to uncoated powder,and the corrosion rate of coated powder in 3.5wt％ NaCl solution decreased over 4 orders of magnitude.%运用液相化学沉积技术制备了二水磷酸氢钙包覆镁粉粉末.利用扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)及傅里叶变换红外光谱仪(FT-IR)分析包覆层特征,用比表面积和孔隙度分析仪测定包覆前后粉末的比表面积,并通过浸泡实验研究包覆粉末的腐蚀行为.结果表明,包覆处理后的镁粉颗粒仍保持球形,表面形成了一层厚度2～4 μm细片状的二水磷酸氢钙(DCPD),与未包覆粉末相比,其比表面积增加约60倍,在3.5％(质量分数)NaCl溶液中的耐腐蚀性能提高四个数量级.