形状记忆合金表面纳米管阵列的制备与表征

Fabrication and Characterization of Nanotube Arrays on Shape Memory Alloy

采用阳极氧化方法在镍钛形状记忆合金表面成功制备出氧化物纳米管阵列。实验结果表明,阳极氧化电压和温度是影响纳米管生长的重要因素。当阳极氧化电压较低时,温度效应不大,合金表面仅形成数十纳米厚的氧化物薄膜。当阳极氧化电压升至20V,在20℃阳极氧化可形成双氧化物层(表面为不均匀多孔纳米结构,下部为具有两种不同直径的纳米管阵列);增大阳极氧化温度至30℃,表面多孔纳米结构溶解,露出底部的纳米管阵列;当阳极氧化温度增大至50℃时,纳米管开始出现破裂。纳米管为Ni-Ti-O氧化物,纳米管的镍含量与镍钛基体相比有所降低。

The oxide nanotube arrays were successfully fabricated on Ni-Ti shape memory alloy by anodization.The experimental results indicate that the anodization voltage and temperature are main factors to influence the growth of the nanotubes.For a lower anodization voltage,the anodization temperature had little effect on the surface structures,and a thin film with several tens of nanometer thickness was formed on the surface of the alloy.When the anodization voltage increased to 20 V,the double oxide layers（The top surface is the irregular nanoporous oxide layer and the bottom is the nanotubes arrays with two different diameters.） were formed at 20 ℃.Upon increasing the anodization temperature to 30 ℃,the nanoporous layer on the top surface dissolved to expose the nanotube array layer at the bottom.When the anodization temperature was further increased to 50 ℃,the nanotubes began to rupture.The as-fabricated nanotubes are Ni-Ti-O oxides and the amount of Ni in the oxide nanotubes is lower than that in the Ni-Ti substrate.