医用NiTi合金表面无镍TiO2层的制备与表征∗

摘要

A dealloying treatment method was applied to the surface modification of NiTi alloy so as to prepare a Ni-free layer.The structure and surface morphology of films were systematically studied by X ray diffracmeter (XRD)and scanning electron microscope (SEM);the elements were analysed by photoelectric spectrometer (XPS);corrosion resistance property was researched by electrochemical workstation;biocompatibility and blood compatibility were also studied. The result showed that,the dealloying treatment of NiTi alloy at low temperature led to a Ni-free surface layer that the corrosion resistance was improved and the rutile type TiO2 was obtained by annealing at 800 ℃. The alloy surface had the ability to induce the deposition of Ca/P after dealloying treatment and the anticoagulat property was significantly improved that clotting time was extended from 45 min of the substrate to more than 60 min.%采用低温去合金化法在镍钛合金表面制备了无镍层。借助扫描电子显微镜(SEM)、X 射线衍射仪(XRD)、光电能谱仪(XPS)及电化学工作站等仪器对表层的形貌、结构、元素、耐腐蚀性、生物活性及血液相容性进行了研究。结果表明，镍钛合金经过去合金后，可以在合金表面制备无镍层，耐腐蚀性能也得到了改善，并经过800℃退火可得到金红石型TiO2；去合金试样表面具有诱导 Ca/P 沉积的能力，且抗凝血性得到显著提升，凝血时间从基材的45 min延长到60 min以上。