化学镀镍对铁基形状记忆合金性能的影响

铁基形状记忆合金具有价格低、易加工、不必进行低温变形处理和低温储藏等优点，通过热机械循环处理等方法来有效地提高其回复率，但是耐酸、盐腐蚀性能较差。对铁基形状记忆合金进行化学镀镍表面处理后，在基本保持铁基形状记忆合金优点的同时，大幅度提高了耐酸、盐腐蚀能力，从而拓宽了铁基形状记忆合金的应用范围。     

铁基形状记忆合金马氏体相变研究进展

铁基形状记忆合金的形状记忆效应和超弹性取决于合金的马氏体相变特征,掌握铁基合金的马氏体相变规律是开发和优化铁基形状记忆合金的前提。根据马氏体相变类型将目前发现的铁基形状记忆合金分成3类：Fe-Mn-Si系,Fe-Ni-Co系和Fe-Pt／Fe-Pd系,分别阐述了3类铁基形状记忆合金马氏体相变的研究进展,总结了铁基合金形状记忆效应的不同机理和影响马氏体相变特征的各种因素,探讨了开发新型铁基形状记忆合金的需要关注的方向。     

铁基形状记忆合金的研究进展与展望

铁基形状记忆合金由于价格低廉、强度高、加工性能好、使用方便等优点引起广泛重视。本文较详细论述了 90年代以来国际上铁基形状记忆合金的研究进展和应用前景     

形状记忆合金研究的最新进展及应用

本文分别综述铜基、Ti-Ni,铁基形状记忆合金近年的应用开发情况,研究动向及目前研制的新型形状记忆合金,使读者能概括了解国内外形状记忆合金开发研究的现状及发展趋势。     

铁基形状记忆合金的研究进展和展望

铁基形状记忆合金由于价格低廉强度高、加工性能好、使用方便等优点引起广泛重视。本文较详细论述了９０年代以来国际上铁基形状记忆合金的研究进展和应用前景。     

铁基形状记忆合金内涨环在管道连接中的应用

铁基形状记忆合金内涨环用于管道焊接内补口，在焊接余热作用下，可产生预期记忆回复，与钢管形成过盈配合，从内提高了焊缝区的缝蚀能力。     

机械合金化和粉末冶金法制备Fe-Mn-Si基形状记忆合金的研究进展

铁基形状记忆合金由于价格低廉、强度高、加工性能好、可焊接等优点引起广泛重视。机械合金化(MA)和粉末冶金(PM)作为制备材料的新工艺,可以用来制备性能优越的形状记忆合金。本文详述了机械合金化和粉末冶金工艺在制备Fe-Mn-Si基形状记忆合金过程中对合金相变、组织与性能的影响,以及此类合金在新领域的应用。最后提出了现阶段在研究MA/PM工艺制备Fe-Mn-Si基SMA中有关工艺参数、相变机制以及回复应力和低温应力松弛所存在的问题。     

Fe-Mn-Si基形状记忆合金记忆效应的研究现状

Fe-Mn-Si形状记忆合金具有原料丰富、价格低廉、力学性能好、切削性能好等优点,具有广阔的应用前景。对Fe-Mn-Si基形状记忆合金的记忆机理研究进行了介绍,着重讨论了Mn、Si、Cr、Ni含量对记忆效应的影响,并对现有提高形状记忆合金记忆效应的方法进行了总结。介绍了Fe-Mn-Si形状记忆合金在工程中的实际应用,指明了未来的研究方向。     

铁基形状记忆合金研究进展

铁基形状记忆合金是继镍钛和铜基合金之后,新崛起的形状记忆材料。本文在回顾铁基形状记忆效应发展历史的基础上,详细介绍了Fe-Mn-Si记忆合金研究动态、涉及应力诱导γ-ε马氏体转变晶体学、应力诱导型形状记忆效应产生机制,和Fe-Mn-Si记忆合金的基本特性。     

形状记忆材料研究综述

综述了镍钛、铜基、铁基形状记忆合金,热致型、光致型、电致型、磁致型、化学感应型形状记忆高分子,以及形状记忆陶瓷的形状记忆机理、特性及其应用现状,并提出形状记忆材料的研究方向为：加强形状记忆合金的抗疲劳性能研究,建立一套统一的研究方法和合理的评价体系;加强形状记忆高分子材料的结构设计研究;改善陶瓷的形状记忆性能,以拓展形状记忆陶瓷的应用领域。     

Cast Pipe Joints of Fe‐15Mn‐5Si‐8Cr‐5Ni‐0.25C Shape Memory Alloy with High Carbon Content

Abstract: The cast pipe joint of the Fe‐15Mn‐5Si‐8Cr‐5Ni‐0.25C alloy was manufactured (the numbers in the composition denote the weight percentage of the elements while the weight percentage of Fe is the balance). The corresponding microstructure and shape memory effect are compared with those of a forged alloy. The results show that the cast joint has a good shape memory effect and may be industrially applied while the cast joint keeps jointing under a tensile force of 20 kN and a sealing pressure of 5 MPa. Moreover, it is found that the addition of nitrogen in the alloy doesn’t evidently improve the shape memory effect of the alloy.     

In vitro investigation of Fe30Mn6Si shape memory alloy as potential biodegradable metallic material

Fe30Mn6Si alloy was investigated as a potential degradable biomaterial, with the recently well-developed biodegradable metals, pure iron and Fe30Mn alloy, as comparison. The microstructure, mechanical properties, shape memory effect, corrosion behavior and in vitro biocompatibilities were evaluated by X-ray diffraction, scanning electron microscopy, tensile tests, electrochemical tests, immersion tests in Hank's solution till 6 months, cytotoxicity and hemolysis tests. It's found that Fe30Mn6Si alloy consists of ε-martensite and γ-austenite at room temperature, the mechanical property of Fe30Mn6Si alloy is higher than that of the pure iron, and the corrosion rate of Fe30Mn6Si alloy is higher than that of Fe30Mn alloy. Additionally, Fe30Mn6Si alloy shows good performance for blood vessel related cellular application and the hemolysis percentage is less than 2%. In conclusion, Fe30Mn6Si alloy is a promising biodegradable metallic material with a shape memory function.     

Fe-Mn-Si基合金形状记忆效应的研究进展

概述了Si、Mn、Ni、Cr等化学成分以及时效处理和预变形等一些工艺因素对Fe-Mn-Si基形状记忆合金形状记忆效应的影响。对此类合金的形状记忆效应作用机理及其发展状况进行了概括总结,并提出了未来进一步的研究方向。     

Pitting Corrosion of Cu-Zn-Al Shape Memory Alloy in Simulated Uterine Fluid

Electrochemical test technology and surface analysis method were employed to investigate the pitting corrosion of Cu-Zn-AI shape memory alloy in simulated uterine fluid. The results showed that the breakage of the breaking-renovating equilibrium of surface layers resulted in the pitting corrosion of Cu-Zn-AI shape memory alloy in simulated uterine fluid. The development of pitting corrosion was controlled by dissolution of surface layers. The critical pitting corrosion potential was 1.70 VSCE. The kinetics equation for the development of pitting corrosion for Cu-Zn-AI shape memory alloy in simulated uterine fluid was io=465.68 t-0.5+1.5. Pitting appearances of pits could be two types: tortoise-shell, and anomaly abscess. Cl- ion facilitated the pitting corrosion of Cu-Zn-AI shape memory alloy by competing adsorption and concentrating on alloy surface at high positive potential.     

Effect of tellurium on machinability and mechanical property of CuAlMnZn shape memory alloy

The microstructure transition, shape memory effect, machinability and mechanical property of the CuAlMnZn alloy with and without Te have been studied using X-ray diffraction analysis, chips observation and scanning electron microscopy (SEM), tensile strength test and differential scanning calorimeter (DSC), and semi-quantitative shape memory effect (SME) test. The particles with richer Te dispersedly distributed in grain interior and boundary with size of 2-5 μm. After the addition of Te, the CuAlMnZnTe alloy machinability has been effectively increased to approach that of BZn15-24-1.5 and its shape memory property remains the same as the one of CuAlMnZn alloy. The CuAlMnZn shape memory alloys with and without Te both have good ductility as annealed at 700 °C for 15 min.     

FeMnSiCrNiCo合金记忆性能的研究

针对具有良好耐蚀性的FeMnSiCrNiCo系合金 ,确定了合理的热加工及固溶处理温度 ,研究了预变形量、退火温度及记忆训练对合金记忆性能的影响 ,并分析了微观组织。结果表明 ,随着预变形量增加 ,记忆回复率 (ηm)下降 ,但记忆回复应变量 (εm)有一个最佳值。合金的记忆性能和微观组织随训练退火温度变化而不同 ,训练退火温度对训练效果起十分关键的作用 ,母相亚结构是决定合金记忆性能的根本因素     

形状记忆合金混杂复合材料层板的有限元分析与强度研究

形状记忆合金(SMA)与复合材料层板结合后,构成可驱动材料。形状记忆合金的非线性及其与复合材料层板的结合界面的力学性能对整体材料的性能影响较大。通过对埋入形状记忆合金驱动器的复合材料层板进行有限元模拟分析与试验研究,用有限元模拟分析的方法可以比较准确地模拟埋入形状记忆合金后复合材料的应力分布情况,结果表明,形状记忆合金的埋入不会对材料的强度产生较大影响。     

内窥检查系统主动引导驱动技术的研究

提出一种医用内窥检查系统的主动引导驱动装置，由蠕动式柔性移动机构和基于形状记忆合金的转向机构组成。蠕动式柔性移动机构通过充气气体的膨胀橡胶囊与腔道壁接触，因而具有较好的柔软性；采用通电调节形状记忆合金元件的方法，可改变转向机构弯曲角度，以适应腔道的变化。     

Effect of martensite transformation on fracture behavior of shape memory alloy NiTi in a notched specimen

In this paper, the finite element calculation of the stress–strain distribution in front of a notch tip were carried out for two materials. One is a shape memory alloy NiTi with the stress-induced martensite transformation, and another is a fully transformed martensite NiTi without the transformation. Based on the results obtained, and combining a model of the fracture process zone, effect of martensite transformation on the fracture behavior of the shape memory alloy NiTi in a notched specimen of plane stress state is comparably analyzed. The results show that the martensite transformation increases the load to produce plastic deformation in the transformed martensite at the notch tip and decreases the maximum normal stress and plastic strain near the notch tip, and tends to suspend the crack nucleation and propagation in the fully transformed martensite in front of the notch tip, and thus increases the fracture load and improves the toughness. A quantitative analysis based on the model of the fracture process zone shows that the martensite transformation in the SMA NiTi causes about 47% increase in the apparent fracture toughness.     

Basic design guidelines for SMA/epoxy smart composites

The actuating ability and reliability of shape memory alloy (SMA) hybrid composites were studied in this paper. Results showed that by selecting small hysteresis SMAs such as TiNiCu alloy, SMA hybrid composites have a linear stress–temperature behavior, which is relatively easy to control. The curing process of the epoxy matrix does not affect significantly the actuating ability of the embedded TiNiCu alloy wires. A moderate prestrain of the TiNiCu wires is preferred when giving attention to both the mechanical properties and the reliability of the TiNiCu hybrid composites. Additional reinforcing fibers with a negative thermal expansion coefficient such as Kevlar fibers are helpful to strengthen the reliability of the interface and enhance the actuating ability of the SMA hybrid composites. Based on the experimental results, some basic guidelines for designing shape memory hybrid composites were proposed.