DEVELOPMENT OF NEW DENTAL FUNCTIONAL TITANIUM ALLOYS

为开发新型牙科生物材料，研究了相变温度低、力学性能好的形状记忆TiPd合金。采用X射线衍射仪、硬度计和拉伸试验机对Ti-42.5mol%Pd和Ti-50mol%Pd合金的TiPd-Co合金进行了分析。TiPd-Co合金在Ti-42.5mol%Pd基合金中沉积了无形状记忆效应的Ti2Pd、Ti2Co和I.C.(无公度)相，但如果选择适当的合金成分和热处理温度，这些相的数量可以减少。例如，在90 0ﾟC淬火的Ti-37.5mol%Pd-5mol%Co合金中没有出现这些相，以Ti-50mol%Pd合金为基础的TiPd-Co合金在较低温度下表现出形状记忆效应。研究发现，Ti-30mol%Pd-20mol%Co合金在20C温度下仍具有形状记忆效应。由于TiPd为单一的β相，因此该合金在牙科生物材料中应具有良好的力学性能和形状记忆效应。但TiPd-Co合金的耐蚀性不如SUS316L不锈钢。应通过添加一些元素来提高其耐腐蚀性。

Shape memory TiPd alloys which has low transformation temperature and good mechanical properties was invetigated in order to develop new dental biomaterials. TiPd-Co alloys based on Ti-42.5mol%Pd and Ti-50mol%Pd alloys were analyzed by X-ray diffraction, hardnes test and tensile test. Ti_2Pd, Ti_2Co and I.C.(incommensurate) phases without a shape memory effect deposited in TiPd-Co alloys based on Ti-42.5mol%Pd alloy, but these phases could be decreased if an alloy composition and heat treatment temperature could be chosen adequately. For example, those phases did not appear in the Ti-37.5mol%Pd-5mol%Co quenched from 900ﾟC.TiPd-Co alloy based on Ti-50mol%Pd alloy showed a shape memory effect at lower temperature. It was founded that Ti-30mol%Pd-20mol%Co alloy has a shape memory effect even at 20C.Because of a single beta TiPd phase, the alloy should have desirable mechanical properties and a shape memory effect for dental biomaterials. But the corrosion resistance of the TiPd-Co alloys were inferior to that of SUS316L stainless steel. The corrosion resistance should be improved by adding some elements.