Development of Ti-Ni alloy as a stress shielding biomaterial

本研究的目的是评价生物医用应力屏蔽用钛镍合金的冲击应力传递。采用分离式Hopkinson压杆技术，对钛镍合金、钛和不锈钢的圆柱形试件进行了冲击压缩试验。结果表明，钛镍合金的传输脉冲比钛和不锈钢的传输脉冲要低得多。钛镍合金和钛合金的初始应力降幅较大，但钛镍合金的应力降幅远大于钛合金。钛镍合金或钛的入射脉冲与传输脉冲的应力差最大值高于不锈钢，钛镍合金的最大应力降低值显著大于钛或不锈钢。钛镍合金的冲击应力传递比钛或不锈钢小，提示钛镍合金作为种植体系统的组件材料可以降低对邻近组织的加载应力。用差示扫描量热仪研究了合金的相变行为，这是影响应力传递的一个重要因素。

The purpose of this research was to evaluate the impact stress transmission of Ti-Ni alloy for biomedical stress shielding. An impact compression test was carried out with use of split-Hopkinson pressure-bar technique with cylindrical specimens of Ti-Ni alloy, titanium and stainless steel. As a result, the transmitted pulse through Ti-Ni alloy was considerably depressed as compared with those through titanium and stainless steel. The initial stress reduction was large through Ti-Ni alloy and titanium, but the stress reduction through Ti-Ni alloy was much more continuous than titanium. The maximum value in the stress difference betweeen incident and transmitted pulses throgh Ti-Ni alloy or titanium was higher than that through stainless steel, while the stress reduction in the maximum stress through Ti-Ni alloy was statistically larger than that through titanium or stainless steel. Ti-Ni alloy transmitted less impact stress than titanium or stainless steel, which suggested that the loading stress to adjacent tissues could be decreased with use of Ti-Ni alloy as a component material in an implant system. Transformation behavior of the alloy, which is an important factor on the stress transmission, were alos investigated by means of DSC.