共查询到18条相似文献,搜索用时 93 毫秒
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材料的电子态密度、能量、能带结构、差分电荷密度以及局域态密度对材料的抗腐蚀性有重要影响。本文基于第一性原理密度泛函平面波赝势法,优化了Fe、Fe-Al、Fe8Al8La电子结构,并从态密度、峰值分析了Fe-Al合金耐腐蚀性机理。结果表明,在Fe-Al合金中加入La, Fe与La之间存在明显的电荷转移并形成了离子键,使Fe-Al的能带宽度降低到30.8 eV,表明La减弱Fe-Al原子轨道的扩展性,La使Fe-Al态密度的峰值增大到30.26 electron/eV,成键的电子数逐渐增加,提高了Fe-Al的稳定性和抗耐腐蚀性能,为提高Fe-Al合金的性能奠定一定理论基础。 相似文献
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为了进一步提高Fe-Al二元阻尼合金的阻尼性能和力学性能,并认识在较高温度下长时间使用对其阻尼性能的影响,利用倒扭摆、拉伸、光学金相等方法测试了微量Si元素和不同时效时间对Fe-Al基合金阻尼性能、力学性能、微观组织的影响.结果表明,在Fe-Al合金中添加少量Si元素,合金的阻尼性能、力学性能优于Fe-Al合金,晶粒也得到明显细化.350℃长时间时效前后,实验合金的阻尼性能、力学性能、微观组织保持稳定.Fe-Al-Si阻尼合金具有更加全面的阻尼和力学性能,并可在350℃下长时间使用,应用范围更广阔. 相似文献
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为改善Fe-Al金属间化合物的力学性能及抗高温氧化性能,利用氩弧熔覆方法在Q235钢上制备了Fe-Al熔覆层和Fe-Al/Al_2O_3熔覆层。采用金相显微镜、X射线衍射仪、硬度计、磨粒磨损试验机对氩弧熔覆涂层进行显微组织结构观察和磨损性能测试。采用高温氧化试验对涂层的耐高温氧化性进行了研究。结果表明:Fe-Al熔覆层形成FeAl和Fe_3Al相,而Fe-Al/Al_2O_3熔覆涂层含有FeAl、Fe_3Al和Al_2O_3相;熔覆层的耐磨粒磨损性能优于基体且Fe-Al/Al_2O_3熔覆层优于Fe-Al熔覆层;熔覆层的耐高温氧化性能明显提高,在700℃下,Fe-Al熔覆层和Fe-Al/Al_2O_3熔覆层相比于基体分别提高了4.46和5.68倍。 相似文献
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Effects of Mo and Zr on Microstructure, Mechanical Properties and Wear Resistance of Fe-Al Based Alloys 总被引:1,自引:0,他引:1
In this work the microstructure, mechanical properties and wear resistance of Fe-Al based alloys with various alloying elements were studied. The microstructures were examined by optical and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectroscope (EDS). Two types of alloys were prepared by vacuum arc melting. One is Fe-28Al based alloys (D03 structured) with and without alloying elements such as Mo and Zr. The other one is Fe-35Al based alloys (B2 structured) produced with the same manner. For both types of alloys, Mo addition had found to exhibit an equiaxed microstructure, while dendritic structure was observed to show the effect of Zr addition. These microstructural features were more evinced with increasing content of alloying element. Concerning the mechanical properties and wear resistance, Fe-35Al based alloys were superior to Fe-28Al based alloys over the whole temperature range investigated. 相似文献
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Peng ZHANG Yunhui DU Hanwu LIU Daben ZENG Jianzhong CUI Limin BADepartment of Mechanical Engineering Beijing Jiaotong University Beijing ChinaDepartment of Mechanical Engineering Tsinghua University Beijing ChinaMetal Forming Department Northeastern University Shenyang ChinaAnshan Automobile Fittings Factory Anshan China 《材料科学技术学报》2004,20(2):193-195
Fe-AI compound at the interface of steel-mushy AI-20Sn bonding plate was studied quantitatively. The relationship between ratio of Fe-AI compound at interface and bonding parameters (such as preheat temperature of steel plate, solid fraction of AI-20Sn slurry and rolling speed) was established by artificial neural networks perfectly. The results show that when the bonding parameters are 505℃ for preheat temperature of steel plate, 34.3% for solid fraction of AI-20Sn slurry and 10 mm/s for rolling speed, the reasonable ratio of Fe-AI compound corresponding to the largest interfacial shear strength of bonding plate is obtained. Its value is 72%. This reasonable ratio of Fe-AI compound is a quantitative criterion of interfacial embrittlement, that is, when the ratio of Fe-AI compound at interface is larger than 72%, interfacial embrittlement will occur. 相似文献
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为了研究热处理对铁铝焊接界面组织和性能的影响,本文采用电容储能焊得到铁铝焊接接头,并对部分焊接接头进行热处理。利用显微镜、X射线能谱仪和显微维氏硬度仪对未热处理和热处理的焊接接头界面处的微观组织、化学成分和性能进行对比和分析。结果表明:热处理后焊接接头界面处有Fe-Al金属间化合物生成;热处理后的焊接接头融合区的铝含量比未热处理的低;焊接接头界面处由于铁铝原子的互扩散,硬度较铁、铝基体有所提高;热处理的焊接接头界面处的硬度高于未热处理的界面处硬度。热处理促使金属间化合物的生成,有利于改善焊接接头性能。 相似文献
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包埋渗铝法可在钢基体表面制备出一层致密、坚固、连续的Fe-Al渗层,以改善基体性能。本文在不同温度和不同时间下对Q235低碳钢进行包埋渗铝,形成Fe-Al渗层,采用X射线衍射、扫描电镜及能谱分析等方法研究了渗铝层的物相结构、表面及截面形貌和成分,采用显微硬度仪测量了截面硬度。结果表明,不同渗铝温度下获得的渗铝层,主要含有Fe2Al5和FeAl3两相,且750℃得到的渗层存在较多Fe2Al5相;随着渗铝温度升高,Fe-Al渗层厚度增加,Al原子扩散系数增大,但显微硬度降低;不同渗铝时间下制备的渗铝层,物相仍以Fe2Al5和FeAl3为主,但随着渗铝时间延长,FeAl3含量减少,且Al原子扩散系数变大,渗层显微硬度略有降低。在进一步分析Fe-Al渗层形成的热力学与动力学基础上,总结了渗铝层形成的扩散机制。 相似文献
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The bonding of steel plate to aluminum liquid was conducted using rapid solidification. The influence of diffusion time on interfacial structure was studied. The results showed that under the condition of 750(C) for the temperature of aluminum liquid and 200(C) for the preheat temperature of steel plate, when diffusion time was shorter than 4.3 s, there was only Fe-AI solid solution at the interface. When diffusion time was longer than 4.3 s, Fe-AI compound began to form at the interface. The relationships between diffusion time t and thickness of Fe-AI compound layer H are H=-9.72+2.62t-0.08t2 (4.3 s15 s). 相似文献