AZ91HP镁合金激光熔凝层的耐蚀性和生物相容性

Corrosion resistance and biocompatibility of AZ91HP alloy melted layer treated by laser

为提高医用AZ91HP镁合金的耐蚀性和生物相容性,采用激光熔凝技术对镁合金进行熔凝处理。结果表明,AZ91HP镁合金熔凝层相组成为α-Mg和β-Mg17Al12,凝固组织为典型的树枝晶。模拟体液中腐蚀速率结果表明,熔凝层的耐蚀性较原始镁合金显著提高。在Hank’s中浸泡21 d后,可清楚看到一些絮状物沉积在熔凝层表面;能谱分析结果表明,絮状物中Ca,P比约为1.33,接近羟基磷灰石中Ca,P比(1.67)。原始镁合金的凝血酶原时间(PT)值为11.025 s,激光熔凝层的PT值为12.025 s,熔凝层具有较好的抗凝血性。细胞毒性实验结果表明,培养1 d后,在原始镁合金周围细胞出现破碎和固缩,极少数贴壁细胞。熔凝层表面则存在许多粘附细胞,熔凝层细胞死亡率较原始镁合金大有降低。

In order to improve the corrosion resistance and biocompatibility of AZ91 HP Mg alloy,Mg alloy melted layer was treated by laser melting technology. The results show that the melted layer is composed of α-Mg and β-Mg17Al12 phases,and the solidification structure of the melted layer is the dendrite. The melted layer has better corrosion resistance than the untreated alloy. After immersed in Hank's for 21 days,the surface of melted layer produces the flocculent sediment. EDS result shows that Ca / P in the flocculent sediment is 1. 33,which is close to Ca / P of hydroxyapatite. Prothrombin time of the untreated alloy is 11. 025 s,prothrombin time of the melted layer is 12. 025 s,and so the melted layer has better anticoagulant activity. The result of the cytotoxicity experiment shows that after cultured for 1 day,the surface of the untreated alloy appears the damage cell and pyknosis cell,and has few adherent cells. The melted layer has many adherent cells. The cell mortality of the melted layer is far below than that of the untreated alloy.