共查询到20条相似文献,搜索用时 156 毫秒
1.
2.
3.
4.
金属管道是实现气、油、矿等海洋资源连续、快速运输的重要载体。在复杂严酷的海洋环境中,金属管道的内、外壁要同时承受海水环境和运输物质带来的化学腐蚀与物理摩擦耦合工况,极易发生由腐蚀与磨损导致的管道破坏和失效。对金属管道进行表面涂层改性与强化处理是提升其使役性能最直接有效的方法。为此,综述了海洋环境和运输介质对金属管道的腐蚀磨损行为,并按照涂层的物质种类(金属涂层、陶瓷涂层和高分子涂层),介绍了常见的海洋金属管道防护涂层研究现状,全面总结对比了不同防护涂层材料的微观结构、力学性能、耐腐蚀性能、耐磨损性能及其腐蚀作用机理,以期为涂层新材料及新结构的创新设计与性能优化提供有益借鉴。在此基础上,对未来海洋金属管道防护涂层材料的发展趋势及其组分结构的研究方向进行了展望,以求为海洋金属管道防腐领域的研究提供一定的参考与支撑。 相似文献
5.
6.
7.
有机涂层因操作便捷、成本低廉在金属防腐领域备受青睐,其中环氧树脂因其显著的化学惰性、对基材的优异附着力和优良的力学性能而被广泛应用。然而环氧涂层在固化过程中因收缩或溶剂蒸发而产生空隙和导电通道,降低了其防腐效率。解决这一问题的策略是向环氧涂层中加入纳米颜填料。本文针对当下应用于环氧防腐涂层的纳米颜填料进行了总结,详细阐述了非金属纳米填料(包括无机非金属纳米填料和有机纳米填料)和金属纳米材料,特别是新型纳米填料(MOFs材料和MXene材料)的性能及改性现状,并对其应用前景进行了展望。 相似文献
8.
9.
研究一种用于烧结NdFeB永磁体表面防护的新型铝微粉涂层技术.用扫描电镜和X射线衍射仪分别测试了涂层的形貌和涂层在形成过程中的物相变化:用盐雾试验、极化曲线、EIS测试涂层的耐蚀性能,并对涂层的成膜和耐蚀机制进行分析.结果表明:铝微粉涂层呈层层重叠结构,对烧结NdFeB提供阴极保护,与铬氧化物的自钝化作用发生协同效应使得涂覆后的烧结钕铁硼耐盐雾腐蚀100 h. 相似文献
10.
钢铁构件表面上的无机富锌涂层 总被引:8,自引:1,他引:8
阐述了无机富锌涂层的研究、发展、特性和应用,指出无机富锌涂层具有杰出的耐环境侵蚀性能、耐化学性、耐溶剂性、耐辐射性、耐热性,在恶劣腐蚀环境下它是钢结构件的最佳底涂层。 相似文献
11.
12.
13.
Calcium phosphate materials such as hydroxyapatite (HA) have biocompatible properties that can promote osteogenesis or new
bone formation. Thermal spraying is an economical and effective process for coating the hydroxyapatite onto metal. It has
been reported that plasma spraying changes the degree of crystallinity as well as the phase composition of the HA. This article
reports the preparation and characterization of HA powders and coatings by two thermal spray processes (plasma and combustion
flame) and suggests that the state of the starting powder adversely affects the coating characteristics. The raw HA powders
are synthesized through a chemical reaction involving calcium hydroxide and orthophosphoric acid. Phase analysis using an
X- ray diffractometer revealed that the synthesized powder consists of predominantly the HA phase. Calcined and crushed HA
powders of various size ranges were fed into the plasma jet to produce HA coatings on metallic substrates. In addition, some
HA powders were sprayed into distilled water by plasma spraying and combustion flame spraying to study powder melting characteristics.
Other samples were plasma sprayed onto a solid rotating target to study atomization and impact behavior. The morphology of
the rapidly solidified powders and thermal sprayed coatings were examined by scanning electron microscopy (SEM). An X- ray
sedimentation particle size analyzer, laser diffraction particle size analyzer, and image analyzer performed the particle
size analysis. Preliminary results indicate that particle cohesion, size range, and thermal treatment in the plasma affect
the phase and structure of the as- sprayed coating, and some post- spray treatment may be necessary to produce a dense and
adherent coating with the desired biocompatible properties. 相似文献
14.
15.
The mismatch between the thermal expansion coefficients of ceramics and metals and the differential stresses it causes at
the interface create problems in metal to ceramic joining. Research has been con-ducted to solve this problem in thermal barrier
coating technology. Previous studies have considered met-al-ceramic multilayers or graded-coatings, which include a metallic
bond coat. In this study, a graded plasma-sprayed metal-ceramic coating is developed using the deposition of premixed metal
and ceramic powders without the conventional metallic bond coat. Influences of thickness variations, number, and composition
of the layers are investigated. Coatings are prepared by atmospheric plasma-spraying on In-conel 718 superalloy substrates.
Ni-Cr-Al and ZrO2 -8 % Y2O3 powders are used for plasma spraying. Ad-hesive and cohesive strength of the coatings are determined. The concentration profile
of the elements is determined by x-ray energy-dispersive analysis. The microstructure and morphology of the coatings are investigated
by optical and scanning electron microscopy (SEM). Results show that the mixed metal-ce-ramic coating obtained with the deposition
of premixed powders is homogeneous. The morphology and microstructure of the coatings are considered satisfactory. 相似文献
16.
分别描述了纳米氧化锆粉体与空心球氧化锆粉体的制备工艺,分析了不同工艺影响氧化锆产物形态、结构、粒度等方面的因素,并将2种粉末制备的涂层分别与传统微结构涂层进行性能对比。在分析由不同氧化锆粉末制备而成的涂层性能时,除了工艺参数外,更多的是考虑初始氧化锆粉末对涂层性能所带来的影响。期待在未来的研究中,能够优化现有或者探索出更优异的制粉工艺,研究出性能更加优良的新型粉末,以期能够提高热障涂层的性能,满足高精尖领域在未来的使用需求。最后,针对不同制粉工艺及不同粉末制备涂层的发展方向进行了展望。 相似文献
17.
18.
从溶剂萃取反向胶团合成优质ZrO_2超细粉 总被引:3,自引:0,他引:3
提出了结合化工单元操作-溶剂萃取,实现金属氧化物超细粉制备的新方法,选择磷酸三丁酯(TBP)-煤油-盐酸的工业化萃Zr体系,实验确定了反向胶团溶液形成的条件,即高酸度及相对较高的萃取金属离子浓废,并以氨水为沉淀剂使之与反向胶团溶液反应,将沉淀物洗涤干燥焙烧,得到粒径10nm单分散的ZrO_2粉 相似文献
19.
制备了一种含有天然无机矿物微粉的摩擦处理剂,采用SEM、XRD、EDS分析了该摩擦处理剂的成分及结构,基于原位摩擦化学处理技术设计了环-块磨损试验,研究了摩擦处理剂对45钢摩擦学性能的影响,采用纳米压痕仪测试了原位形成的摩擦化学转移膜的纳米硬度和弹性模量等力学性能,探讨了摩擦化学处理过程及其化学转移膜的形成规律.结果表明,摩擦处理剂的主要成分为羟基硅酸镁,其结晶构造式为Mg3(Si2O5)(OH)4.通过摩擦化学处理,摩擦处理剂在45钢表面原位生成了含Si、Mg、Fe、C等元素构成的摩擦化学转移膜,从而使金属的表面硬度提高33%,摩擦系数降低15%,表面粗糙度是未处理的1/4. 相似文献
20.
利用扫描电子显微分析(SEM)、X射线衍射分析(XRD)、中性盐雾实验以及电化学交流阻抗等技术,研究了Al粉的形态与尺寸对热烧结锌铝涂层表面形貌、耐蚀性及其在海水中电化学性能的影响。结果表明,Al粉的存在改善了涂层外观色泽、提高了涂层耐蚀性和控制了涂层中的Zn粉在腐蚀介质中溶解消耗的速率,从而延长了涂层寿命,其中尺寸较小、分散性好的Al粉效果更好。 相似文献