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1.
离子注入用于金属材料表面改性,特别是提高金属表面的耐磨损、耐腐蚀能力的试验研究已开始向工业应用的方向过渡。目前这方面的研究成果已在英国、美国、日本、苏联等国申请了专利,其中用于磁头表面处理的专利申请就占有两项。为此,我们分别试验了硼离子、氮离子注入坡莫合金磁头材料,研究其组织、结构的变化,测量了坡莫合金离子注入前后的磁性能、表面硬度、表面光洁度、耐磨损性能以及成品磁头离子注入前后的电声性能,取得了一些初步的试验结果。  相似文献   

2.
离子注入对超高分子聚乙烯磨损性能的影响   总被引:4,自引:0,他引:4  
用80keV不同剂量的C3H^+8,N^+2对超高分子聚乙烯样品进行离子注入,通过反冲探测分析表明注入层H含量的变化,对样品表面在离子注入前后的磨损性能进行了测试。实验结果显示,离子注入以后样品表面氢含量减少,磨损性能增强。  相似文献   

3.
离子束辅助沉积铌提高铀的抗腐蚀性能研究   总被引:2,自引:0,他引:2  
利用离子注入技术在铀表面进行了离子束辅助沉积铌和离子注入铌形成表面改性层,并对改性层的厚度、注入元素的分布进行俄歇电子能谱(AES)分析和表面相及结构的X射线衍射谱(XRD)分析,用电化学极化法测试抗腐蚀性能。结果表明:离子束辅助沉积表面改性层比离子注入表面改性层明显增厚,铀的耐蚀性得到进一步改善。最后讨论了注铌改性层耐蚀性提高的原因。  相似文献   

4.
唐辉 《核技术》1998,21(7):445-448
介绍并分析了喷丸自理技术作为核设备提高疲劳强度、耐应力腐蚀、耐磨损等表面强化处理的现代通用技术,因其适用于多种复杂结构、环境和各种材料,能进行在线强化处理等优点,使其在核电工程中的应用具有重要地位。  相似文献   

5.
用V+C双重离子注入H13钢合成表面优化层的研究   总被引:4,自引:1,他引:3  
黄华鹏  孙贵如 《核技术》1995,18(2):65-72
给出了C,V离子和V+C双重离子注入H13钢合成表面优化层机理的研究结果,包括表面薄碳膜和弥散硬化层的形成。用电镜观察到离子注入时晶粒细化和新相的析出,使晶界强化和位错强化效果增强。俄歇分析表明C,V离子注入浓度将分别达到50%和30%的原子比便,即形成固溶化。X射线衍射分析表明,注入层中出现了弥散的Fe2C,Fe5C2,FeV和V2C相。注入样品退火,这些相的衍射峰增强,说明这些相在生长。由于这  相似文献   

6.
设计一种无钴镍基合金材料Ni-3,其在高温下耐磨损和耐腐蚀性能接近或超过钴基合金。在350℃左右的温度下分别对Ni-3、Norem02和Stellite06进行高温摩擦磨损及高温腐蚀的实验。分析结果表明,Ni-3是一种较为理想的无钴合金材料,在高温耐磨损和耐腐蚀性能方面都比代钴材料Norem02优越;与钴基合金相比,Ni-3高温耐磨损性能与之接近,高温耐腐蚀性能稍逊色。在一定范围内,Ni-3可以替代目前在核阀、化工等阀门密封面上普遍使用的堆焊合金。  相似文献   

7.
Cu离子和Al离子注入M2钢表面改性研究   总被引:9,自引:0,他引:9  
王超  刘正民 《核技术》2001,24(4):295-299
报道了M2型高速工具钢在Cu,Al离子注入后表面硬度及抗磨损性的变化。对注入样品进行了显微硬度及抗磨损性的测量和XRD与RBS分析,观察了表面强化与离子注入条件之间的关系。结果显示,注入样品与未注入样品相比,表面硬度及抗磨损性均有显著提高。分析结果表明,Cu,Al离子注入后样品中产生了不同的相,它们对表面强化所起的作用不同。  相似文献   

8.
用能量为110keV、剂量为3×1017ions/cm2的C+对单晶Ta进行了注入,分析了注入层的成分分布及其结构,考察了注入前后表面层摩擦磨损性能的变化及其特征。结果表明,C+注入层含有hcpTa2C及bccTa(C)相,其强化效应造成了注入层硬度、耐磨性的提高和摩擦系数的下降;样品表面与淬火态GCr15钢球间的磨损机制也由未注入时的粘着磨损转化为注入后轻微的磨粒磨损。  相似文献   

9.
双元素离子注入机及其在航空发动机主轴轴承上的应用   总被引:1,自引:0,他引:1  
为了延长航空发动机主轴轴承的使用寿命,在自制的双元素离子注入机上对GCr15和M50两种轴承钢材料的试样、轴承试验件和正式轴承零件进行了双元素离子注入,注入能量为100 keV.经检测,GCr15和M50两种材料经N、Ti两种元素注入后,摩擦系数和耐磨损、耐腐蚀、抗疲劳等性能都得到了显著提高.轴承的内外套圈、滚柱和钢球注入的均匀性都达到了87%以上.  相似文献   

10.
报道了聚酚亚胺薄膜在高能(650keV-2MeV)B+、C+和Cu+离子注入后硬度的变化。对注入样品进行了显微硬度测量和XPS及RBS分析,观察了硬度与离子种类、能量及注入剂量的依赖关系。结果表明,离子注入之后薄膜样品的显微硬度值明显提高,注入离子在样品中的电子能量损失对聚合物材料改性起着关键作用。XPS和RBS分析显示,离子注入之后聚酰亚胺薄膜中C的含量增加,形成了以苯环结构为主的新的交联网状结构。  相似文献   

11.
Chromatographic methods of separating elements with very similar properties have now been developed. However, a number of these methods are difficult to use industrially as their throughput is low. The efficiency of chromatographic separation methods could be increased considerably by using appropriate complex formers, which decrease the effective concentration of the ions being separated, and,in the first approximation, this is equivalent to a decrease in the amount of elements being separated. The difference in the formation constants of the complex compounds increases the separation coefficient. By investigating chromatographic separation with the use of various complex formers, we found the optimal conditions for separating barium and radium, zirconium and hafnium, and aluminum and gallium. The throughput of these methods, with respect to the macroelement was 15–60 kg/hr per m2 of column cross section.  相似文献   

12.
随着核与辐射技术在医学检查、诊断和治疗领域运用的增加,世界范围受照人群不断增多,医源性辐射已成为人类最主要的人工辐射来源之一。医疗机构和个人在选择利用放射手段获取诊断和治疗利益的同时,需要注意和防护伴随的辐射损伤效应。本文介绍了医源性辐射及其危害、机体组织的辐射损伤特性和类型、辐射生物效应分子及效应调节研究的进展,简要概述目前临床已经使用或最具应用潜力的辐射防护策略。  相似文献   

13.
14.
The selective removal and fixation of Cs and Sr have been studied in zeolite A and chabazite. Cesium ion was preferentially distributed into chabazite with a high distribution coefficient (K Cs>103 cm3·g?1) in the presence of NaCl (10?1 mol·dm?3). The K Sr values for zeolite A attained about 103 cm3·g?1 in the pH range of 8~10, and they gradually decreased with an decrease in pH.

The initial rate of Cs adsorption was fairly fast in chabazite, and the adsorption ratio reached almost 100% within a few hours. The adsorption ratio of Sr in binderless A zeolite reached almost 100% after 15 h. The adsorption of Cs and Sr on these zeolites was followed by Langmuir-type isotherm. Cesium forms of these zeolites recrystallized to pollucite (CsAlSi2O6) above 900°C for zeolite A and above 1,200°C for chabazite. As for Sr forms, these zeolites changed to SrAl2Si2O6 above 900°C.

These recrystallized phases were suitable hosts for the immobilization of Cs and Sr in the nuclear waste solutions.  相似文献   

15.
清洁解控和退役若干动向与新发展   总被引:2,自引:0,他引:2  
对国际辐射防护协会第 1 0届大会 ( IRPA-1 0 )涉及的清洁解控和退役问题作了论述 ,包括排除、豁免、清洁解控和废物最少化 ;退役工程技术的发展 ,包括去污技术、切割解体技术、探测技术 ;介绍了一个研究堆退役例子和加速器退役 ;最后 ,还论及了退役中受关注的一些问题 ,如 :石墨废物、混凝土废物、重水堆退役的氚防护、退役时间和退役废物量等。  相似文献   

16.
17.
This paper depicts one theoretical and experimental method to take into account the energy phenomena, associated with the elasto—plastic deformation process, during the elaboration of behaviour laws. The energy balance definition is examined in order to relate the stored energy of cold work to the hardening state variables. Two experimental approaches are used to study the evolution of the energy balance. The first one uses microcalorimetric technique and the second infrared technique. Several industrial metallic materials are studied by both approaches. Energy data are used to control the validity domain of the classical behaviour laws and to elaborate new more appropriate ones. Therefore, the hardening parameters cannot be identified with the thermodynamical forces. The use of energy considerations allows the definition of new thermodynamical forces and state variables, in the case of isotropic or kinematical hardening.  相似文献   

18.
文章简要介绍了全国核与辐射安全监管信息系统的前期规划建设情况,包括基本建设内容、系统总体架构、以及工作中发现的影响和制约工作开展的主要问题,并提出了建议。  相似文献   

19.
This work developed an advanced boiling water reactor (ABWR) feedwater pump and controller model, which was incorporated into Personal Computer Transient Analyzer (PCTran)-ABWR, a nuclear power plant simulation code. The feedwater pump model includes three turbine-driven feedwater pumps and one motor-driven feedwater pump. The feedwater controller includes a one-element/three-element water level controller and a specific feedwater speed controller for each feedwater pump. The performance tests, including step change of dome pressure, feedwater pumps transfer, inadvertent closure of all turbine control valves, and one feedwater pump trip at 100% power, demonstrate the feasibility of dynamic response of stand-alone model and incorporated model. Furthermore, a diversity and defense-in-depth analysis is performed to demonstrate the feasibility for motor-driven feedwater pump as an emergency core cooling system (ECCS) automatic diverse back-up. In Lungmen nuclear power plant (NPP), a diverse manual initiation means for the high pressure core flooder (HPCF) loop C is designed as the back-up of digitalized engineered safety features actuation system (ESFAS). If the motor-driven feedwater pump (MDFWP) can be an automatic digital diverse back-up for ESFAS, Lungmen NPP would be more robust to defend against software common-cause failure (CCF).  相似文献   

20.
Past experience with small and medium power reactors (SMPRs) in the areas of construction and operation is examined in this paper. Current development of SMPRs focuses on passive safety features; larger design and safety margins; reduction of construction periods through simplification, modularization and increased shop fabrication.  相似文献   

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