Microstructure and superelasticity of porous NiTi alloy

The microstructure, porosity, phase composition and superelasticity (SE) in porous NiTi alloys produced by elemental powder sintering are examined by SEM, image analysis and XRD. It is found that it is feasible to produce porous NiTi alloy by elemental powder sintering, and the porosity of sintered porous NiTi alloy is in the range of 36.0 %-41.5 %. The pores are interconnected and the microstructure is sponge-like. Meanwhile, porous NiTi alloy has good SE. XRD patterns show that there is no pure Ni in alloy sintered at 1223 K-9 h. Compared with the biomedical criteria for choice of implanting materials, porous NiTi alloy is satisfying to a great degree.     

生物医用多孔Ti-Ni形状记忆合金的研究进展

综述了多孔Ｔｉ－Ｎｉ形状记忆合金的发展历史、制备技术、生物相容性、力学性能及其应用等方面的研究进展。一种用于人体硬组织修复和替换的新型生物医用材料－多孔Ｔｉ－Ｎｉ形状记忆合金,由于其多孔结构及独特的形状记忆与伪弹性、优良的生物相容性和力学性能等特点。伴随其制备工艺的改进,已经引起世界各国科学家的极大关注。     

多孔形状记忆合金的变形特性及热—机械循环对形状记忆性能的影响

研究了传统粉末烧结制备工艺及热－机械循环压缩变形对多孔ＮｉＴｉ形状记忆合金变形和记忆特性的影响,结果表明,承烧结温度升高,合金的轴向应变恢复率和弹性应变均显著提高,可见,提高烧结温度有利于合金的形状记忆和弹性性能,同时发现,少量（二次）热－机械循环压缩变形可显著提高合金的应恢复率和可逆应变,从而进一步改善了多孔形状记忆合金的形状记忆性能。