不同阳极氧化时间下常规和超细晶TiNi合金的生物活性

Bioactivity of Conventional TiNi and Ultrafine-grained TiNi Alloy Under Different Anodic Oxidation Times

研究了不同阳极氧化处理时间下常规TiNi和超细晶TiNi合金表面形貌及其浸泡在体外模拟体液(SBF)下21天后的生物活性。结果表明:与常规TiNi合金相比,超细晶TiNi合金含有数量略多的微米尺度沟壑,生物活性亦较高。氧化时间从3min增加到9min时,合金的氧化程度增加,常规TiNi合金的生物活性(模拟体液中Ca-P层的生长速率)显著增加,而超细晶TiNi合金的生物活性仅轻微增加;Ca/P比都出现明显下降,常规TiNi合金的Ca/P比从1.68降低到1.44,超细晶TiNi合金从1.62下降到1.43。这表明TiNi合金组织超细化增加了其生物活性,适当延长氧化时间有助于进一步提高合金的生物活性。

The surface morphology and bioactivity after immersion in simulated body fluid （SBF） for 21 days of conventional TiNi alloy and ultrafine-grained TiNi alloy under different anodic oxidation times were investi- gated. The results show that compared with the conventional TiNi alloy, the anodic oxidized surface of ultrafine- grained TiNi alloy slightly exhibits more micrometerscale donga and higher bioactivity. With the increase of anodic oxidation time from 3 min to 9 min, the conventional TiNi alloy exhibits much higher bioactivity （growth rate of Ca-P layer in SBF）, while the ultrafine-grained TiNi alloy only exhibits slightly higher bioac tivity. The Ca/P ratios of conventional TiNi alloy and uhrafine-grained TiNi alloy decrease from h 68 to 1.44, and from 1.62 to 1.43, respectively. It means that the ultrafinement processing of microstructure is an effective approach to improve bioactivity, and appropriate extension of anodic oxidation time contributes to further enhancement of bioactivity.