钙化液对NiTi形状记忆合金表面HAP涂层形貌的影响

Effect of calcified solution on microstructure of HAP coating on the surface of NiTi shape memory alloy

为改善NiTi形状记忆合金的使用安全性,利用外加电场处理技术在其表面涂覆羟基磷灰石涂层。试验研究钙化液的浓度、浸泡时间对涂层形貌的影响及涂层生成过程中溶液pH值的变化情况。结果表明:获得最佳形貌涂层的钙化液浓度为Ca2+3.10 mmol/L、K+4.64 mmol/L、Na+126.8 mmol/L、Cl-144.5 mmol/L、HPO24-1.86mmol/L,作用时间为7d;涂层生产过程中,溶液的pH值显著降低后缓慢变化至某一稳定值。

In order to improve the security of NiTi shape memory alloy, the external electrical technology has been used to deposit hydroxyapatite coating on the surface of NiTi shape memory alloy. The experi- ment studied the effect of calcified solution and dipping time on the microstructure of coating and the change of solution pH. The results showed that： when the consistence of calcified solution was Ca2＋ 3.10 mmol/L,K＋4. 64 mmol/L,Na＋ 126.8 mmol/L, Cl- 144. 5 mmol/L, HPO4^2- 1.86 mmol/L and the dipping tine was 7 d, the microstructure of coating was best; the solution pH reached a constant after evidently reduced during the coating deposition.