羟基磷灰石梯度涂层的制备及其结构特征

SYNTHESIS AND STRUCTURAL CHARACTERISTICS OF FUNCTIONAL GRADIENT HYDROXYAPATITE COATINGS

通过改变电结晶电流密度在钛合金表面制得内部致密、外部多孔的ＣａＨＰＯ４·２Ｈ２Ｏ 涂层，经碱液处理转变为羟基磷灰石．ＳＥＭ，ＸＲＤ分析及粘接拉伸试验表明：电流密度较小时得到的内部涂层致密，与基体有较高的结合强度；随电流密度增加得到的涂层由内向外孔隙率逐渐增大，晶体变为细针状． 这种梯度结构实现了生物涂层结合强度和表面形态的协调兼顾．

Functional gradient hydroxyapatite (HA) coatings on Ti-6Al-4V were synthesized by electro_crystallization with current density regularly changed and then treated by alkaline solution. SEM, XRD and tensile as well as bonding tests of the coatings were performed. The results show the interlocked plate_like dense crystals exist inside the coatings when current density is small, and needle_like porous crystals, which are similar to the bone apatite crystals, exist outside of the coatings when current density is high. The gradient structure can improve the bonding strength between the coating and the substrate and may be beneficial for tissues to grow in the coating.