共查询到20条相似文献,搜索用时 125 毫秒
1.
膨胀防火涂层广泛用于体育场馆等大跨度钢结构的防护,而很多钢结构材料往往暴露在室外,往往会与周围环境中的水,空气等发生化学腐蚀和电化学腐蚀。因此涂层的防腐蚀性能某种程度上决定了钢材的使用寿命。研究表明纳米材料和纳米技术为防腐蚀涂料的开发提供了新的途径。提高树脂或涂料防腐蚀性能的纳米材料主要有:纳米CaCO3、TiO2、纳米氧化锌、纳米SiO2通常是以添加一定量的纳米材料填补微观缺陷来提高涂层的防腐蚀性能。 相似文献
2.
稀土纳米材料的研究进展 总被引:1,自引:0,他引:1
稀土纳米材料的研究与应用将有助于发现新性质,开拓新材料,已成为当前的研究热点.本文简述了稀土纳米粉体、稀土纳米薄膜、稀土纳米陶瓷和纳米复合与组装的研究进展,介绍了在磁性材料、发光材料、催化剂、光学材料等领域稀土纳米材料的应用和进展. 相似文献
3.
4.
5.
6.
7.
8.
5纳米材料中微结构的表征和研究
纳米材料是一个不十分明确的概念,可能是纳米大小、纳米尺度、纳米颗粒或纳米晶粒材料的通称,所谓纳米级材料是大小、尺度、颗粒或晶粒在1-100nm范围的材料。 相似文献
9.
10.
聚氨酯/纳米复合材料的研究进展 总被引:6,自引:0,他引:6
本文简述了纳米材料在聚氨酯中的应用,重点介绍纳米CaCO3、纳米SiO2、纳米碳材料及粘土对聚氨酯的改性研究,并指出了聚氨酯/纳米复合材料未来的研究方向. 相似文献
11.
Structural nanocrystalline materials: an overview 总被引:1,自引:0,他引:1
Carl C. Koch 《Journal of Materials Science》2007,42(5):1403-1414
This paper presents a brief overview of the field of structural nanocrystalline materials. These are materials in either bulk,
coating, or thin film form whose function is for structural applications. The major processing methods for production of bulk
nanocrystalline materials are reviewed. These methods include inert gas condensation, chemical reaction methods, electrodeposition,
mechanical attrition, and severe plastic deformation. The stability of the nanocrystalline microstructure is discussed in
terms of strategies for retardation of grain growth. Selected mechanical properties of nanocrystalline materials are described;
specifically strength and ductility. Corrosion resistance is briefly addressed. Examples of present or potential applications
for structural nanocrystalline materials are given. 相似文献
12.
C. Suryanarayana 《Bulletin of Materials Science》1994,17(4):307-346
The present article reviews the current status of research and development on the structure and properties of nanocrystalline
materials. Nanocrystalline materials are polycrystalline materials with grain sizes of up to about 100 nm. Because of the
extremely small dimensions, a large fraction of the atoms in these materials is located at the grain boundaries, and this
confers special attributes. Nanocrystalline materials can be prepared by inert gas-condensation, mechanical alloying, plasma
deposition, spray conversion processing, and many other methods. These have been briefly reviewed.
A clear picture of the structure of nanocrystalline materials is emerging only now. Whereas the earlier studies reasoned out
that the structure of grain boundaries in nanocrystalline materials was quite different from that in coarse-grained materials,
recent studies using spectroscopy, high-resolution electron microscopy, and computer simulation techniques showed unambiguously
that the structure of the grain boundaries is the same in both nanocrystalline and coarse-grained materials. A critical analysis
of this aspect and grain growth is presented.
The properties of nanocrystalline materials are very often superior to those of conventional polycrystalline coarse-grained
materials. Nanocrystalline materials exhibit increased strength/hardness, enhanced diffusivity, improved ductility/toughness,
reduced density, reduced elastic modulus, higher electrical resistivity, increased specific heat, higher thermal expansion
coefficient, lower thermal conductivity, and superior soft magnetic properties in comparison to conventional coarse-grained
materials. Recent results on these properties, with special emphasis on mechanical properties, have been discussed.
New concepts of nanocomposites and nanoglasses are also being investigated with special emphasis on ceramic composites to
increase their strength and toughness. Even though no components made of nanocrystalline materials are in use in any application
now, there appears to be a great potential for applications in the near future. The extensive investigations in recent years
on structure-property correlations in nanocrystalline materials have begun to unravel the complexities of these materials,
and paved the way for successful exploitation of the alloy design principles to synthesize better materials than hitherto
available. 相似文献
13.
14.
高温高压酸性气井腐蚀环境恶劣,油套管腐蚀、变形、破损等事故频繁发生,严重影响气井安全生产。为了解掌握油套管钢的腐蚀类型、严重程度及耐蚀性能,利用高温高压反应釜在模拟井底实际工况条件下研究了J55、N80、P110、13Cr、S13Cr 5种油套管材质的抗CO_2腐蚀性能,运用失重法、扫描电镜(SEM)和能谱分析等技术,重点分析了腐蚀速率、腐蚀产物膜形貌和腐蚀产物膜成分。结果表明:在本试验测试范围内,J55、N80、P110钢在90℃时腐蚀速率为最大,然后随温度升高而降低,属于极严重腐蚀;13Cr、S13Cr钢的腐蚀速率随温度的升高不断增大,在150℃达到最大值;5种材料的平均腐蚀速率随CO_2分压的增大呈先上升后下降的趋势;碳钢材质腐蚀类型主要为均匀腐蚀+局部腐蚀,含Cr钢材质腐蚀类型主要为均匀腐蚀;碳钢CO_2腐蚀产物膜主要成分为FeCO_3,同时夹杂有少量的Fe_3C和铁的氧化物或铁单质;13Cr和S13Cr钢CO_2腐蚀产物膜的主要成分为晶态FeCO_3和非晶态的Cr(OH)_3,此外,还含有少量的Fe或Cr的氧化物、碳化物和单质Fe等。 相似文献
15.
16.
17.
18.
19.
20.
镍合金在天然海水中的腐蚀行为 总被引:3,自引:0,他引:3
目前,尚未见到关于镍合金在我国海域的腐蚀行为的报道,这给镍合金在海水中的应用带来不便,为此,通过天然海水暴露试验,获得了9种镍合金在青岛海域全浸区、潮汐区暴露1年、2年、4年、7年的腐蚀结果,讨论了它们在海水中的腐蚀行为.结果表明,镍合金在海水中的耐蚀性相差很大.NS334,NS335,NS336,GH3128在海水中有很好的耐蚀性,Hastelloy-G和GH181有好的耐蚀性.镍合金在潮汐区的耐蚀性比全浸区好.机械划伤、加工残余应力增加镍合金对点蚀的敏感性.海生物污损对NS112和NS312在海水中的腐蚀有明显影响.添加Cu,Cr,Mo,W能提高镍合金在海水中的耐蚀性.该试验结果为实际应用提供了参考. 相似文献