共查询到19条相似文献,搜索用时 93 毫秒
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TiNi形状记忆合金的研究动向 总被引:2,自引:0,他引:2
简述了TiNi形状记忆合金(SMA)的研究与应用进展,指出了今后的发展方向。重点介绍了TiNi细丝、微管、薄板、薄带、薄膜的开发思想与应用目标,以及TiNi SMA在智能复合材料方面的应用。TiNi SMA今后的发展方向是尺寸的超小化、超细化、超薄化;相变的高温化;热滞的宽化与窄化;功能的复合智能化以及组织性能的稳定化。有关TiNi基SMA方面的新工艺、新材料及新用途的开发也是今后的研究方向。 相似文献
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形状记忆合金是一种过去人们尚未认识的物理-机械性能的新型合金,合金的奇特功能可解决许多工程上的问题,因此倍受各国科学家的重视,并相继对合金基础理论及其应用开展研究。合金的形状记忆是由热弹性马氏体转变引起的,据称这一现象是在1949年前苏联学者Г.В.库尔纠莫夫和Л.Г.汉德罗斯所发现。TiNi形态记忆合金 相似文献
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TiNi合金具有出色的形状记忆性、低的刚度、出色的耐蚀性和生物相容性,与人骨的力学性能匹配优于其他植入材料,是重要的医用植入材料。此外,富Ni的TiNi多孔材料还具有出色的超弹性,是理想的减震用结构材料。通过调整TiNi孔材料多孔型及孔隙率,可以得到出色的阻尼减震效果,并对材料的力学性能进行调控,极有可能应用于震动保 相似文献
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形状记忆合金的应用非常广泛,在医学方面,支架、导管、导引丝、血过滤器等医疗器件,已经越来越广泛地采用TiNi形状记忆合金及超弹性合金制作;在工业领域,管接头及紧固件,驱动器,智能复合材料,阻尼材料,日常用品等各个方面,都可见到TiNi形状记忆合金的身影。1 医学方面的应用TiNi形状记忆合金在医学方面的应用始于70年代末,90年代得以迅速发展。其原因并不是TiNi形状记忆合金材料价格的下降,而是因为:(1)微创医疗技术的发展对新型医疗器件的需求增加,而这些新型医疗器件采用传统的材料难以制造;(2)TiNi 毛细管及其激… 相似文献
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Ni—Ti合金的超弹性工艺研究 总被引:1,自引:0,他引:1
介绍了Ni-Ti形状记忆合金超弹性的机理,超弹性特征以获得超弹性的工艺要点。并在本所的“形状记忆合金综合测试仪”上分析了Ni含量,加工工艺以及热处理对超弹性性能的影响。同时介绍了部分超弹性的应用。 相似文献
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文献中极少能见到用穆斯堡尔效应研究TiNi合金的文章,这是因为TiNi合金中没有穆斯堡尔核素,而在其中产生穆斯堡尔发射源又是极其困难和复杂的工作,本工作在回旋回速器中用质子轰击Ti-51.6at.%Ni合金,获得了适合穆斯堡尔方法测量的同位素。初步分析结果表明穆斯堡尔谱的参数对Ti44Ni56合金沉淀相是敏感的,并有助于了解TiNi合金微结构和性能。 相似文献
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本文简要叙述了冷加工获取NiTi合金超弹性的工艺方法,冷加工变形量和热处理对超弹性能的影响,进而讨论了超弹性的相变本质。 相似文献
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用光学显微镜、SEM、EDX系统研究了Ni含量对TiNi形状记忆合金铸态和固溶淬火室温组织的影响。给出了i含量变化TiNi合金组织的变化规律。 相似文献
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燃烧合成TiNi形状记忆合金及其性能 总被引:6,自引:2,他引:4
介绍了用燃烧合成技术由元素粉末制备TiNi形状记忆合金的方法及合成产物的性能。获得的TiNi合金锭坏具有单一TiNi相的铸态组织,成分准确,纯度高,为致密态,有良好的冷热加工塑性。最终加工材的力学性能和形状记忆性能与市售同类材料相当甚至更好。 相似文献
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研究TiNi合金的宏观电磁性质与微观电子态的关系. 由TiNi合金样品的霍尔效应实验得出样品的霍尔系数为9.6×10-6 Ωm·T~(0.1). 由霍尔系数求得电子浓度n为6.5×10~(23)/m~3, 比金属电子浓度n的值小5个量级, 电学性质比金属弱得多. 而磁性测量得出TiNi合金中有很少的铁磁性晶粒, 但铁磁相很弱, 顺磁相为主相. 样品的表观顺磁磁化率为χ=(2.55±0.01)×10~(-4)(SI), 实际的顺磁磁化率的数值为4.3×10~(-4)(SI), 比金属的Pauli顺磁磁化率的数值大一个量级. TiNi合金与金属相比, 电性弱而磁性强. 电磁实验结果证明TiNi合金未满的3d与4s电子杂化后成为巡游电子, 与金属的公有化电子相比, 它们的载流能力减弱, 而局域磁性增强. 相似文献
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Zoheir Farhat George Jarjoura Meisam Shahirnia 《Metallurgical and Materials Transactions A》2013,44(8):3544-3551
The large recoverable deformation associated with reversible stress-induced martensitic transformation for superelastic TiNi alloys has been widely exploited in many applications. However, to employ superelastic TiNi in applications where high impact loading is expected, as in bearings, the effect of loading rate on superelasticity needs to be understood. In the current article, the effect of indentation loading rate on dent resistance and superelasticity of TiNi is studied. Indentation tests are performed, at different loading rates on superelastic TiNi alloy and correlated to tensile stress–strain data. It is found that the reversible deformation drops as loading rate is increased and superelasticity diminishes. Based on data collected and results analysis it is proposed that the loss in superelastic behavior under high indentation loading rate is related to retardation of the stress-induced martensitic transformation. Furthermore, a simple heat model was proposed and showed that the temperature rise during indentation is not significant. 相似文献
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Wear characteristics of TiNi shape memory alloys 总被引:7,自引:0,他引:7
H. C. Lin J. L. He K. C. Chen H. M. Liao K. M. Lin 《Metallurgical and Materials Transactions A》1997,28(9):1871-1877
The wear characteristics of TiNi shape memory alloys against Cr-steel have been studied. Experimental results indicate that
the Ti49Ni51 alloy can exhibit a better wear resistance than Ti50Ni50 alloy due to their higher hardness and pseudoelastic behaviors. Four main mechanisms, adhesion, abrasion, surface fatigue,
and brinelling, are found to have important contributions to the wear characteristics of TiNi alloys. The weight loss increases
with increasing wear load and sliding distance but decreases with increasing sliding speed. The contact area during sliding
wear will be increased due to the variant accommodation and/or pseudoelasticity and, hence, will reduce the average compressive
stress and wear damage. Variant accommodation and/or pseudoelasticity can also stabilize the crack tips and hinder crack propagation,
hence improving the wear characteristics of TiNi alloys. 相似文献
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TiNi alloy foams are promising candidates for biomaterials to be used as artificial orthopedic implant materials for bone replacement applications in biomedical sector. However, certain problems exist in their processing routes, such as formation of unwanted secondary intermetallic phases leading to brittleness and deterioration of shape memory and superelasticity characteristics; and the contamination during processing resulting in oxides and carbonitrides which affect mechanical properties negatively. Moreover, the eutectic reaction present in Ti-Ni binary system at 1391?K (1118?°C) prevents employment of higher sintering temperatures (and higher mechanical properties) even when equiatomic prealloyed powders are used because of Ni enrichment of TiNi matrix as a result of oxidation. It is essential to prevent oxidation of TiNi powders during processing for high-temperature (>1391?K i.e., 1118?°C) sintering practices. In the current study, magnesium powders were used as space holder material to produce TiNi foams with the porosities in the range of 40 to 65?pct. It has been found that magnesium prevents secondary phase formation and contamination. It also prevents liquid phase formation while enabling employment of higher sintering temperatures by two-step sintering processing: holding the sample at 1373?K (1100?°C) for 30?minutes, and subsequently sintering at temperatures higher than the eutectic temperature, 1391?K (1118?°C). By this procedure, magnesium may allow sintering up to temperatures close to the melting point of TiNi. TiNi foams produced with porosities in the range of 40 to 55?pct were found to be acceptable as implant materials in the light of their favorable mechanical properties. 相似文献