Materials Engineering Department, University of Tabriz, Tabriz, Iran.
J Mater Sci Mater Med. 2019 Aug 6;30(8):92. doi: 10.1007/s10856-019-6296-9.
Having similar properties with natural bone, has made porous NiTi shape memory alloy (SMA) a promising material for biomedical applications. In this study porous NiTi SMA has synthesized with 30 and 40 vol.% green porosity by self propagating high temperature synthesis (SHS) from elemental Ni and Ti powders. After synthesizing, the average porosity of specimens reached to 36.8 and 49.8% for green compacts with 30 and 40 vol.% of green porosity, respectively. Combustion products were characterized by XRD, SEM, EDS and electrochemical polarization test. Although desired B2 (NiTi) phase was the dominant phase, other phases like TiNi, NiTi and NiTi are found. Electrochemical polarization analysis in simulated body fluids (SBF) shows that, synthesized porous NiTi has better corrosion resistance than solid one and hydroxy apatite coating on porous NiTi worsen electrochemical corrosion resistance which is because of bioactive behavior of hydroxy apatite.
具有与天然骨相似性能的多孔 NiTi 形状记忆合金（SMA）成为生物医学应用中很有前途的材料。在这项研究中，通过自蔓延高温合成（SHS）从元素 Ni 和 Ti 粉末合成了具有 30%和 40%绿色孔隙率的多孔 NiTi SMA。合成后，对于具有 30%和 40%绿色孔隙率的绿色压坯，试样的平均孔隙率分别达到 36.8%和 49.8%。通过 XRD、SEM、EDS 和电化学极化测试对燃烧产物进行了表征。尽管主要相是所需的 B2（NiTi）相，但也发现了其他相，如 TiNi、NiTi 和 NiTi。在模拟体液（SBF）中的电化学极化分析表明，合成的多孔 NiTi 具有比实心 NiTi 更好的耐腐蚀性，而多孔 NiTi 上的羟基磷灰石涂层会降低电化学腐蚀抗性，这是由于羟基磷灰石的生物活性行为。
