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金属橡胶用Cr-Ni-Mn系不锈钢丝的微观组织及力学性能研究 总被引:5,自引:2,他引:5
采用光学显微镜、扫描电镜、X射线相定量分析等技术,研究了制备金属橡胶构件用冷变形量分别为36%,64%,84%和91%所得的直径0.4mm,0.3mm,0.2和0.15mm的Cr-Ni-Mn系不锈钢丝的微组织结构和力学性能的变化规律.结果表明,冷拔钢丝中出现了形变马氏体,冷变形量为36%时的马氏体含量已达81.2%,即用于制作金属橡胶构件时奥氏体不锈钢已实际处于以马氏体为主的高强度状态,而非奥氏体状态,且马氏体数量随冷拔变形量有增大趋势;钢丝内部出现平行于拉拔方向的拉长孔洞,其体积分数随冷拔变形量的增大而增加.同时,在所用冷拔变形量条件下,不锈钢微丝的抗拉强度高达1406~2244MPa,延伸率则在13.0%~8.9%范围内变化.从而可以判断,采用上述微丝制作的金属橡胶将是以马氏体相之为主且具有微观和宏观尺度双重尺寸孔洞(孔隙)的多孔金属材料. 相似文献
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Two near single-phase NiTiNb alloys—Ni50Ti48Nb2 and Ni49.5Ti46.5Nb4—are prepared and studied by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential scanning calorimetry (DSC) and tensile tests in order to unearth the effects of Nb-atom solid solution in NiTi phase on the yield strength induced by self-accommodation of martensite variants. The results show that the yield strength of near single-phase NiTiNb alloys varies inversely with the amount of Nb-atoms solid-dissolved in NiTi phase. From the results out of the prior and current studies, it can be surmised that the effects of Nb content on the yield strength of NiTiNb alloys in martensite state depend on the coaction. Nb solid solution weakening mechanism and β-Nb phase composite strengthening mechanism. This inference might be a satisfactory explanation to the fact that the yield strength of (NiTi)50–0.5xNbx alloys in martensite state begins with decline and then rises when the Nb content increases. 相似文献
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Fe—Mn—Si—Cr—Ni形状记忆合金的研究 总被引:2,自引:0,他引:2
利用电子显微镜对Fe-15Mn-5.5Si-12Cr-7Ni(质量分数)形状记忆合金的物理本质进行了研究。结果表明:该合金的记忆效应是靠应力诱发ε-马氏体相变及其逆转变而产生的。ε-马氏体是在应力诱发下由奥氏体基体(111)γ面层错处形核产生的。通过热处理和训练处理后,该合金的记忆效应明显提高。 相似文献
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本文研究了轧制变形及随后热处理对板条马氏体的影响,结果表明:大变形量的重度轧制可使马氏体板条趋于沿轧向排列,层片致密,马氏体板条厚度缩减至20nm左右,在板厚方向上形成了显微层压板结构。低于350℃长时退火,组织处于回复阶段,马氏体形态与轧后近似;高于350℃退火,组织开始进入再结晶期,并有新晶粒生成。 相似文献
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JING Rui-rui LIU Fu-shun 《中国航空学报》2007,20(2):153-156
The influences of Co-addition on phase transformation behavior and mechanical properties of TiNi alloys were investigated. Re- sults indicate that, as a substitute for Ni, Co added to TiNi alloys can dramatically decrease the martensite transformation temperature, and R phase transformation and martensite transformation are accordingly separated. When Co-content reach 10 at.%, the martensite transformation temperature is lower than that of liquid nitrogen. During deformation at room temperature, Ti50Ni48Co2 alloy exhibits good ductility with a lower stress plateau caused by stress-induced martensite and martensite reorientation. 相似文献
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采用光学显微镜、三维视频显微系统、扫描电镜、X射线衍射、有限元仿真模拟等技术,研究了金属橡胶构件以不同轧制率度冷轧以及410~1270℃热轧异型小锈钢微丝的微观组织结构和力学性能的变化规律.实验结果表明,φ0.4mm的原材料冷拉拔不锈钢微丝中形变马氏体含量为82.1%,经冷轧成形后有所增加,经热轧后则有不同程度的减小.轧制成形异型不锈钢微丝内部存在的微孔体积分数比轧制前有所减小,尤其是在固定轧制速率下随轧制温度的降低而减小.冷轧成形异型不锈钢微丝的抗拉强度高达1374~1553MPa,硬度为402~510 HV.若轧制率一定,异型不锈钢微丝的抗拉强度和硬度随轧制温度的升高而降低,延伸率随之增大.模拟结果表明,异型不锈钢微丝轧制成形后截面的变形区域为49.8%. 相似文献
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LI Yan-wu LIU Fu-shun* School of Materials Science Engineering Beijing University of Aeronautics Astronautics Beijing China 《中国航空学报》2006,19(Z1)
The microstructures and interfacial characteristics of matrices at the inwalls and the out-walls of the cold-rolled tube with different amounts of deformation were investigated by the scanning electronic microscope (SEM), the optical microscope (OM), and the trans-mission electronic microscope (TEM) techniques. It was observed that as the amount of deformation increases, the flaws nucleate at the out-walls of the cold rolled tube, the stress-induced martensites change from (111 ) type Ⅰ twins to (011) type Ⅱ twins and then to (100) compound twins, nanocrystals and bulk amorphisation happen, the high density dislocation causes stress concentration at the out-walls of the Ti50Ni50 cold-rolled tube, and then precipitates its fracture, and the Ti2Ni particles strengthen the grain boundaries and curb the dislocation movements during plastic deformation. The inhomogeneity level of the grains in the Ti50Ni50 alloy plays an important role on the fracture of the Ti50Ni50 cold rolled tube. 相似文献
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