表面氮化纯铁生物学性能的研究

Study on the biological properties of pure iron via surface nitride modification

采用气体软氮法对工业纯铁进行表面氮化.用X射线衍射、金相显微镜、扫描电镜分别对样品表面的结构及形貌进行分析,用相变温度分析仪测定纯铁表面氮化层相变温度,用显微硬度仪分析样品表面硬度,通过溶血率、血小板粘附实验表征纯铁表面血液相容性.结果表明:渗氮后铁表面有5μm左右的白亮层,该白亮层为氮铁化合物层,由ε相和γ′相组成,具有较高硬度及脆性,从而使渗氮铁的硬度有显著提高;纯铁溶血率为3.81%,大于氮化处理铁的2.9%;血小板实验证明,表面氮化铁的血小板粘附率较低,表明经氮化处理的纯铁表面生物学性能有所改善.

The gas soft nitrogen method is used to nitride industrial pure iron. The surface structure and morphology of the samples were charactorized by X ray diffraction, optical microscopy and scanning electron microscopy, respectively. The phase transformation temperature of nitrided samples was determined by phase change temperature analyzer, and the surface hardness of allsamples was obtained by microhardness tester. Thehemolysis rate and platelet adhesion test were used to evaluate the blood compatibility. The results show that the nitrided iron surface is about 5μm of the white layer, the white layer is composed of iron, γ phase , γ＇ phase, which has high hardness and brittleness. The hemolysis rate of iron was 3.81% Vs. 2.9% of nitrided iron, the result of plateletadhesion shows that the amount of nitrided iron surface is lower than the pure iron surface, so gas soft nitrogen method is suitable to apply surface modification of pure iron as potential biodegradable biomaterials.