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NbC对FeMnSiCrNi合金组织与记忆性能的影响 总被引:5,自引:2,他引:5
配制了5种不同Nb,C含量的Fel4Mn5Si9Cr5Ni形状记忆合金,测量了不同温度和不同时间条件下固溶-时效处理的合金记忆性能,采用透射电镜和原子力显微镜观察了合金的显微组织。结果表明NbC的析出对合金的形状记忆性能有明显影响,经1200℃,10h固溶处理后的Fel4Mn5Si9Cr5Ni0.5Nb合金,经800℃,6h时效获得了最好的形状记忆性能,且优于无铌Fel4Mn5Si9Cr5M合金经热机械循环训练的记忆性能指标。显微观察表明经过高温固溶.中温时效处理后的该合金中NbC粒子在合金基体时效析出,有利于合金应力诱发细小马氏体核心的形成。 相似文献
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采用光学显微镜、X射线衍射、DSC、弯曲试验等方法研究了Co-Fe合金的微观组织结构、马氏体相变特性及形状记忆效应.结果表明:Co-Fe合金的记忆效应源自合金中的fcc/hcp马氏体相变;Co-xFe(x=2%~6%,质量分数)合金在x≥5.65%时为单一fcc结构的y相,在x≤5.6时为含有ε马氏体相和γ相的双相组织;该合金的马氏体相变温度随着Fe含量的增加而线性降低,之间关系为:Ms(℃)=417-69.97x(Fe%);Co-4Fe合金的形状记忆可回复应变最大为0.86%,相信通过进一步的热处理和记忆训练,该合金会表现出更好的记忆效应. 相似文献
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淬火对Fe—Mn—Si—Cr—Ni记忆合金回复率的影响 总被引:4,自引:0,他引:4
研究淬火加热温度对(W%)Fe-14.9Mn-6.3Si-8.8Cr-5.2Ni形状记忆合金形状回复率的影响。试验结果表明,形状回复率随淬火加热温度升高而提高,700℃ ̄800℃淬火,达到最大值,随后回复率随淬火加热温度进一步升高而降低。淬火加热温度越高,热诱发ε马氏体数量越多。热诱发ε马氏体对形状记忆效应具有双重作用。适量的热诱发ε马氏体有利于提高形状回复率。 相似文献
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WANGGao-chao YANGGang HUANGYi-bin MINSi-lin 《材料热处理学报》2004,25(5):122-125
In order to improve the linear recovery behavior, TiNi shape memory alloy springs were samariumed at 550℃ for 4 hours with SmH3 as samarium source, in a vacuum furnace. The phase of samariumed layer was determined by X-ray diffractometer (XRD). The fracture surface of TiNi SMA spring was investigated by scanning electronic microscope (SEM), The experimental results indicate that a 2μm thick samariumed layer composed of NiSm intermetallics existed on the fracture surface. Additionally, a new idea of linear recovery behavior in shape memory alloy (SMA) has been proposed, and its properties have been defined. The reversion measurements show that the linear recovery properties of TiNi SMA were obviously improved. The temperature range of the linear reversion (Tw) was enlarged from 4℃ to 8℃, The ratio of linear reversion (η) was increased from 54% to 75%, the proportion of linear reversion (PL) was increased from 56% to 70%, and the proportion of non-linear reversion (Ps) was decreased from 44% to 10%, but the proportion of total reversion (PT) has a little decrease. These results were attributed to the strengthening effect of NiSm intermetallics. 相似文献
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热循环对CuZnAl形状记忆合金相变温度和记忆性能的影响 总被引:1,自引:0,他引:1
本文研究了热循环温度,预应变量,稀土加入量对CuZnAl形状记忆合金的相变温度,记忆性能的影响。结果表明,冷热循环能使合金的相变温度温度5℃ ̄6℃,预应变量的提高会导致达到稳定双记忆的循环次数下降,复合稀土加入量小于0.10%时对形状记忆性能影响不大,但可以延缓记忆衰退,提高记忆性能的稳定性。 相似文献
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利用差示扫描量热仪(DSC)、扫描电镜(SEM)和D/max2500PC全自动X射线衍射仪研究了不同时效处理制度下TiNiCr合金相变温度的变化规律.结果表明,该合金随着时效温度增加,逆马氏体相变点As、Af上升,但当时效温度高于700℃时,相变点As、Af降低.该合金在冷却过程中经历了B2→R→B19′两阶段一级相变.通过SEM和XRD衍射研究表明,该合金经时效处理产生了Ti3Ni4析出相诱发了R相变. 相似文献
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形状记忆合金具有传感和驱动功能,是一种新型的智能材料.本文简述了形状记忆合金的特性及其在混凝土自诊断、自修复和在建筑减震隔震方面的研究与应用进展,指出了今后的研究及发展方向. 相似文献
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碳含量对不同淬火态Fe-Mn-Si-Cr-Ni-C系记忆合金回复应力的影响 总被引:3,自引:0,他引:3
研究了碳含量对不同淬火态Fe-Mn-Si-Cr-Ni-C系记忆合金回复应力的影响,结果表明,在650℃淬火时,碳元素的加入能显著提高合金加热时产生的最大回复应力,σh,提高了76%,不同碳含量的合金,加热后冷却室温产生的回复应力σc达到最大值的淬火温度是不同的。在最佳淬火温度下,碳元素的加入能显著提高合金加热后冷却到室温时的回复应力σc提高了42%,在任一淬火温度下,含碳不同的Fe-Mn-Si-c 相似文献
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较详细地叙述了用拉伸试验法测量Ti-Ni形状记忆合金的回复应变和回复力特征的研究结果,并分析了Ti-Ni合金回复应变率和回复应力同低温马氏体状态下残余变形程度之间的关系。 相似文献
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F. Chen Y. X. Tong X. L. Lu B. Tian L. Li Y. F. Zheng 《Journal of Materials Engineering and Performance》2012,21(12):2509-2514
This article studies the dependence of martensitic transformation on Mn:Sn ratio in Ni43Co7Mn50?x Sn x alloy and the shape memory behavior of Ni43Co7Mn43Sn7 in detail. The results show that all the transformation temperatures show a linear decrease with the decrease of Mn:Sn ratio. The similar tendency is also found in the change of T c. Ni43Co7Mn43Sn7 alloy exhibits a moderate shape memory effect and the maximum shape recovery strain is 2.96%. Temperature memory effect is also observed in Ni43Co7Mn43Sn7 alloy. 相似文献
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通过Fe16Mn6Si7Cr7Ni合金变形量的大小和形变的类型来研究马氏体的转变特征.形变类型及变形量为:冷轧13%~28%;拉伸4%~17%.并通过热膨胀法测量合金相转变起始温度和转变终了温度,合金的相组成和微观结构特征通过XRD、SEM获得.研究结果表明:冷变形过程均会导致合金的形状恢复率降低,导致应力诱发ε、α/马氏体的形成,并使热马氏体的帆低于室温. 相似文献
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采用微分扫描式量热法(DSC)、拉伸试验和弯曲试验研究了形变对Ti36Ni49Hf15高温形状记忆合金相变及双程形状记忆效应的影响.结果表明,形变不影响合金的相变顺序.在马氏体状态下变形时,随形变量的增加,Ti36Ni49Hf15合金的马氏体相变温度略有下降,逆马氏体相变温度上升.当形变量一定时,合金在马氏体状态下不同温度变形,对合金的相变温度没有显著影响.Ti36Ni49Hf15高温记忆合金在马氏体状态下直接变形可以产生双程形状记忆效应,其双程可逆应变量随形变量的增加而增加.在随后的热循环过程中,合金的双程形状记忆效应在最初的几次循环过程中迅速下降,而后随循环次数的增加趋于稳定. 相似文献
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Xiaofeng Lu Gang Li Luwei Liu Xiaolei Zhu Shan-Tung Tu 《Journal of Materials Engineering and Performance》2017,26(7):3025-3033
The improvement of the compressibility and recovery of the gaskets can decrease the leakage occurrence in bolted flange connections. In this study, the effect of aging treatment on the compressibility and recovery of NiTi shape memory alloys is investigated as static seals together with thermal analysis. The experimental results indicate that different phase transformations of NiTi alloys are exhibited in the DSC curves during aging treatment. The recovery coefficient of NiTi alloys aged at 500 °C for 2 h is quite low accompanied with a large residual strain. With increasing aging time at the aging temperature of 400 °C, the residual strain and area of hysteresis loop of NiTi alloys are both increased, whereas the recovery coefficient is decreased. Since the deformation associates the phase transformation behavior, aging treatment could improve the compressibility and recovery of NiTi alloys as static seals. 相似文献