航空用宽滞后Ni-Ti-Nb记忆合金管接头研究

一、前言 形状记忆合金第一次成功的应用是美国Raychem公司于1969年生产的Ti_(50)Ni_(47)Fe_3记忆合金管接头用于Grumman航空公司的F—14战斗机上的液压管路系统连接。至今这种记忆合金管接头在美国各种型号飞机上使用已超过150万只,尚未发现一例失效,其连接的可靠性和密封性均达到十分满意的程度,而且实际安装施工简单方便,深受工程界的欢迎。现在,美国所有新的军用飞机几乎都规定用NiTi记忆合金管接头作为液压管路连接唯一的许用系统。但由于NiTi二元合金相变滞后小,制成的记忆合金零件在安装前必须保存在液氮中,因此工程应用很不方便。1986年,美国Raychem公司发展了一种Ni-Ti-Nb宽滞后记忆合金,该合金经适当的低温变形处理后相变滞后(As—Ms)可达150℃,显著高于常用的NiTi和NiTiFe合金(通常约为30℃～50℃),用这种宽滞后记忆合金制成的管接头可在室温下运输、储存,不需保存在液氮中,利于推广应用。此后,航空用记忆合金管接头大量改为Ni_(47)Ti_(44)Nb_9合金,这种管接头只需在-60℃扩径,在常温下保存不发生形状     

铜基形状记忆合金管接头在舰船中的应用研究

用Cu(27-35)Zn-(1.8-2.5)Al记忆合金制作管接头。研究了合金成分设计、热处理工艺对记忆效应的影响及扩管装配接管性能。该管接头已实船安装使用,效果良好。     

Ni—Ti—Nb宽滞后形状记忆合金焊接环拉伸断裂分析

研究了Ni—Ti—Nb宽滞后形状记忆合金点焊环拉伸试验的断裂行为。对形状记忆合金环的断口形貌及微区成分用扫描电镜作了分析,得出了形状记忆合金环中的（Ti,Nb）2Ni硬脆相是导致断裂的主要原因。并分析了（Ti,Nb）2Ni硬脆相形成的原因,提出了利用多次电弧炉熔炼和热变形工艺的方法来提高记忆合金冶金质量的建议。     

形状记忆合金宽滞后效应的研究

综述了NiTi基记忆合金（包括Ni-Ti-Nb)、铁基记忆合金（Fe-Mn-Si系）和铜基记忆合金相变宽滞后的形成机理，以及使形变诱恨马氏体兼具高的稳定性（宽滞后效应）和良好的可逆性（高的记忆应变）的条件（包括合金成分、变形温度及变形量）。     

宽滞后形状记忆合金的研制EI

本研究结果表明，采用两次真空自耗电弧炉熔制的ＴｉＮｉＮｂ宽滞后形状记忆合会，滞后宽度大，力学性能好，杂质含量低，室温下能储运。     

NiTi系形状记忆合金的组织与相变

简述二元NiTi合金中R相变、马氏体相变、沉淀析出相的主要研究成果以及三元窄滞后NiTiCu合金和宽滞后NiTiNb合金的相变和组织特征。     

超微晶NiTiNb合金微观结构与演变

采用快淬法将NiTiNb记忆合金制备成超微晶薄带,晶粒尺寸为400nm～1.5μm,研究了晶粒的微观结构特征及演变过程.结果显示,NiTiNb薄带的微观组织由NiTi和少量的氧化物或碳化物颗粒组成,组织中无富Nb相.富Nb相在高温退火时析出,退火前后的薄带均不发生马氏体转变.     

Ni47 Ti44 Nb9合金丝氩弧焊接头的显微组织和力学行为

系统研究了Ni47Ti44Nb9宽滞后记忆合金带氩弧焊点丝材的显微组织和力学行为.结果表明,焊后适当温度退火处理可显著改善焊点的显微组织,得到细小、均匀的等轴晶,从而提高了焊点的力学性能,室温下表现出较高的拉伸强度和延伸率.焊后未经退火处理的试样,室温拉伸断口均位于焊缝金属的熔合区内,微观断口存在明显的解理台阶,为典型脆性断裂.退火处理后,断口位于近焊缝处的热影响区内,是韧窝型断口,属塑性断裂.韧窝内镶嵌有(Ti,Nb)2Ni相,该相内部及其与基体交界处存在有明显的微裂纹.带焊点丝材经退火处理后在---60℃下变形,最大弯曲可恢复应变约为5%,表明焊点处仍具有一定的记忆效应.     

一种新型整体双管板换热器管接头结构的研发

针对双管板换热器结构存在的弊端,研发了新型整体双管板换热器管接头。介绍新型整体双管板换热器管接头的结构特点、制造工艺和运用推广情况。     

Fe-Mn-Si-Cr-Ni系形状记忆合金管接头形状记忆效应和耐腐蚀性能的研究

研究了Fe-Mn-Si-Cr-Ni系形状记忆合金管接头形状记忆效应和耐腐蚀性能。结果表明,随着预变形量的增加,管接头的形状记忆效应下降,而恢复应变呈上升趋势,当预变形超过5.3%左右时,上升幅度不大;连接状态的管接头在模拟油田介质中的耐腐蚀性能比3.5%的NaCl溶液中的抗蚀性差;在模拟油田介质中,连接状态和未连接的管接头相比,由于回复应力使表面产生拉应力以及应力诱发ε马氏体的存在,使连接状态的管接头耐腐蚀性能下降;随着预变形的增大,由于回复应力、管接头裂纹以及晶体缺陷密度增加的共同作用,使连接状态的管接头耐腐蚀性能降低。     

Einfluss thermomechanischer Behandlung auf eine NiTiNb‐Formgedächtnislegierung für den Einsatz in Kopplungsmechanismen

Influence of thermomechanical treatment on a NiTiNb shape memory alloy for coupling devices The application of shape memory alloys in coupling devices depends considerably on the phase transition temperatures of the material. On the one hand it is important to achieve a high austenite start temperature. On the other hand the difference between martensitic and austenitic transition start‐temperatures should be as large as possible. The present work investigates the influence of thermomechanical treatments on the phase transition temperatures of a NiTiNb alloy. The aim is to optimize the properties of the semi‐product for later applications in coupling devices.     

Fe-Mn-Si基形状记忆合金在管接头方面的研究及应用

回顾了形状记忆合金的发展历史,阐述了Fe-Mn-Si基形状记忆合金的形状记忆机制及其管接头的连接原理,分析了Fe-Mn-Si基形状记忆合金在价廉管接头方面的研究现状,并提出了在这一研究热点中尚待解决的问题.     

Nonlinear free vibration analysis of shape memory alloy embedded laminated composite shell panel

High specific strength and stiffness are characteristics desired for aircraft and launch vehicle domains to enhance the payload gain and performance. The mechanical properties of the composites can be further tailored by embedding structural components, such as shape memory alloys, into the passive composite structure. The present study is primarily focused on the nonlinear free vibration analysis of spherical and cylindrical composite shell panels embedded with shape memory alloy fibers. The nonlinear finite element governing equations based on the higher-order shear deformation plate theory and principle of virtual work with nonlinear von-Karman strain displacement relations are employed for the analysis. The temperature-dependent material properties of shape memory alloy are considered in the formulation. A nine-noded isoperimetric element is accounted for synthesizing the element for the finite formulation. The Young's modulus and the recovery stress vary with temperature and higher nonlinearity. The incremental method is used to generate the inputs for the temperature-dependent nonlinear properties of materials. The temperature change is divided by many small temperature increments. The temperature-dependent material properties are assumed constant during the small increment. The mechanics of shape memory alloy in substrate are presented and the governing equation of laminated composite with shape memory alloy is obtained and implemented in the MATLAB 7.8 program.     

TiNi基形状记忆合金薄膜研究进展

TiNi基形状记忆合金薄膜除具有和体材料相同的形状记忆特性外,还因表面积大、散热能力好,改善了体材料响应速度较慢的缺点,在微电子机械系统领域是一种具有广阔应用前景的材料.综述了近年来TiNi基形状记忆合金薄膜研究现状,并对其应用进行了评述.     

用 NiTi 形状记忆合金制造散热器感温感压活门

采用NiTi形状记忆合金作为散热器的驱动感温活门,利用该合金的热弹性马氏体相变原理,在不改变散热器感温感压活门功能、工作原理的前提下,实现散热功能,提高了空气滑油散热器的寿命及可靠性。     

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.     

形状记忆合金螺旋弹簧设计原理

简要介绍了形状记忆合金螺旋弹簧设计原理的发展现状，讨论了在进行形状记忆合金螺旋弹簧设计时所存在的问题。     

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。     

Investigation on ferromagnetic shape memory alloys

Ferromagnetic shape memory alloys, exhibiting large recoverable strain and rapid frequency response, appear to be promising shape memory actuator material. These materials exhibit large shape memory effect associating with martensitic transformation, and magnetic-field-induced strain in the martensite state. The recent development in researches on NiMnGa, NiFeGa, and CoNiGa in our group is briefly reviewed. The perspectives of the ferromagnetic shape memory alloy are also described.     

TiNi形状记忆合金连接技术的研究进展

TiNi形状记忆合金具有很多优异性能,在航空航天、原子能、海洋开发、仪器仪表以及医疗器械等领域具有广阔的应用前景,而TiNi形状记忆合金的连接技术是其实用化的关键技术之一.综述了TiNi形状记忆合金连接技术的发展现状,重点评述了TiNi形状记忆合金激光焊、固相焊和钎焊的研究状况,指出了需要深入研究的问题.