Ni—Cr—Al电极材料的组织与性能

研究了Ｎｉ２Ａｌ－ＸＣｒ、ＮｉＡｌ－ＸＣｒ二个系列合金的显微组织与结构，并对合金的导电率、维氏硬度和三点弯曲性能进行了测试。本文还就不同Ｃｒ含量对合金性能的影响关系以及Ｎｉ－Ｃｒ－Ａｌ合金作为真空断路器（ＶＣＢ）电极材料的应用前景作了进一步讨论。     

Ni－Cr－Al电极材料的组织与性能

研究了Ｎｉ３Ａｌ—ＸＣｒ、ＮｉＡｌ—ＸＣｒ二个系列合金的显微组织与结构，并对合金的导电率、维氏硬度和三点弯曲性能进行了测试。本文还就不同Ｃｒ含量对合金性能的影响关系以及Ｎｉ—Ｃｒ—Ａｌ合金作为真空断路器（ＶＣＢ）电极材料的应用前景作了进一步的讨论．     

铁氧体电极材料的研究

铁氧体电极材料是一种新型耐腐蚀材料，报告了铁氧体电极材料的制备工艺，测定了它的阻－－温特性，研究了其微观形貌，获得了密度为４．５ｇ／ｃｍ＾３、电阻率１０＾－２Ω．ｃｍ和腐蚀率１．８３６ｇ／ｍ＾２．ａ的铁氧体电极材料，这种是极材料可用于电力的接地体以及其他恶劣环境中。     

Cr、Al对低膨胀Thermo-Span高温合金热腐蚀行为的影响

采用扫描电镜(SME)观测和能谱分析(EDAX)方法研究了改型低膨胀Thermo-Span合金650℃的腐蚀行为,并与标准合金进行了对比。结果表明,合金表面腐蚀产物主要为氧化物和硫化物。合金热腐蚀膜由三层组成,外层主要由Fe、Co和Cr的氧化物组成,改型合金表层还有少量Al和Co的氧化物;次表层为Al、Cr、Ni等元素组成的氧化物;硫化物主要为Ni、Co的硫化物,标准合金硫化物层较厚,而改型合金的硫化物层较薄。改型合金中致密的Al氧化物富积在次表层中,阻止了合金元素的向外扩散和O、S元素的向内扩散,降低了合金的腐蚀速率,提高了合金的耐腐蚀性能。     

光热发电用熔盐及储盐材料腐蚀行为研究进展

集中式太阳能(CSP)光热发电技术利用可再生清洁能源太阳能将热能转化为电能,具有良好的应用前景。对于CSP技术,熔盐是吸热、储热介质,熔盐和储盐材料的研究及发展是关键。从腐蚀动力学、腐蚀产物、熔盐本征等角度分析了不同储盐材料在熔融硝酸盐、碳酸盐、氯盐和氟盐等几种熔盐介质中的腐蚀行为,最后对太阳能光热发电用熔盐及储盐材料进行了总结与展望。     

Fe3Al高温抗磨损腐蚀材料研究

“九五”期间本项目取得的主要科技成果可归结为: (1)在“八五”工作的基础上,通过系统的高温磨损腐蚀试验表明,Fe_3Al基合金具有其它的高温合金不能与之相比的优异的抗高温磨损腐蚀性能,并发现钨、钼和铌等元素对进一步改善Fe_3Al的高温抗腐蚀磨损性能具有显著的效果。在系统总结系列实验结果后,优化了合金的成分,形成了Fe_3Al基抗磨损腐蚀材料的最佳成分配方。 (2)形成了制备和加工Fe_3Al材料大型零件或毛坯件的成套工艺,包括铸造、电渣重熔、锻造和切削加工。其中最具创新性     

燃煤磁流体熔渣对氧化物材料腐蚀的试验研究

用一定碱度的粒化煤渣以高温短时间的埋浸法对材料进行了４次腐蚀试验，最高温度及力应的保温时间分别为１５００℃４ｈ、１５５０℃３０ｈ、１６５０℃３０ｈ、１６５０℃５ｈ和１７００℃５ｈ。试验结果表明：致密的高氧化铝瓷和高氧化锆瓷的耐渣腐蚀性比其它材料的好，用等静压成型、高温烧成的透明氧化铝瓷的耐渣性又是其中最好的。     

Cu的加入对Fe3Si材料在NaCl溶液中的腐蚀行为的影响

以原子比为3：1的Fe粉和Si粉球磨20h后,将球磨得到的Fe（si）粉末和混合了质量分数为5％Cu的Fe（Si）-Cu粉末,在1O00±30℃,20MPa的压力下通过热压烧结的方法制备了Fe3Si和Fe3Si--Cu复合材料。文章通过浸泡腐蚀和电化学腐蚀两种方法讨论了Fe3Si和Fe3Si--5％Cu复合材料在NaCl溶液中的腐蚀行为。实验表明,两种材料在NaCl溶液中的腐蚀过程都是活化过程,Fe3Si在不同摩尔浓度的NaCl溶液中的腐蚀性能要比Fe3Si-5％Cu要好,浸泡腐蚀速率要小,自腐蚀电流也小。     

Crystallization Behavior of Zr_(55)Al_(10)Cu_(30)Ni_5 Bulk Metallic Glass Rolled at Room Temperature

Zr 55 Al 10 Cu 30 Ni 5 bulk metallic glass was rolled up to 95% in thickness reduction at room temperature, and the dependences of microstructure and thermal stability on the strain were investigated. It is revealed that phase transformations do not occur during the rolling, but the split of the crystallization peaks becomes more and more obvious with increasing thickness reduction. Analyses of the radial distribution functions and the pair correlation functions indicate that the rolling has enhanced the sh...     

V40Ti26Cr25Fe8Mo1贮氢合金循环放氢过程研究

考察了V40Ti26Cr25Fe8Mol贮氢合金的循环放氢性能,发现合金放氢量随循环次数呈指数衰减.对合金循环过程中的结构变化分析表明,合金一氢化物的结构在循环过程中由BCC结构向BCT结构转变,同时其晶格应变增长遵循指数增长模型,并且合金放氢量与晶格微应变呈线性关系.     

生物膜对金属材料腐蚀性能影响的研究进展(下)

综述了生物膜对金属材料腐蚀行为的影响,内容包括:海洋极端微生物相关的腐蚀,微生物对航空、航天某些系统的影响以及研究微生物腐蚀所采用的方法等。     

Corrosion behavior of Al_(0.4)CoCu_(0.6)NiSi_(0.2)Ti_(0.25) high-entropy alloy coating via 3D printing laser cladding in a sulphur environment

High-entropy alloys(HEAs) are of great interest in materials science and engineering communities owing to their unique phase structure.HEAs are constructed with five or more principal alloying elements in equimolar or near-equimolar ratios.Therefore,they can derive their performance from multiple principal elements ratherthan a single element.In this work,three-dimensional printing laser cladding was applied to produce an Al_0.4CoCu_0.6NiSi_0.2Ti_0.25 HEA coating.The experimental results confirmed that the laser cladding could be used to produce a thin coating of 120 μm in thickness.In the high-temperature laser cladding process,some Fe elements diffused from the substrate to the coating,forming a combination of face-centred cubic and body-centred cubic phase structures.The HEA coating metallurgically bonded well with the substrate.Owing to the increased dislocation density and number of grain boundaries,the HEA coating was harder and had a stronger hydrophobicity than X70 steel.The electrochemistry results showed that the HEA coating had better corrosion resistance than X70 steel.Aluminium oxides formed on the surface of the HEA coating had a certain protective effect.However,because of the laser cladding,the HEA coating generated cracks.In future work,the laser cladding technology will be improved and heat treatment will be implemented to prevent formation of cracks.     

微波功率器件及其材料的发展和应用前景

介绍了微波功率器件的发展和前景,对HBT,MESFET和HEMT微波功率器件材料的特点和选取,以及器件的特性和设计做了分类说明.着重介绍了SiGe合金、InPSiC、GaN等新型微波功率器件材料.并对目前各种器件的最新进展和我国微波功率器件的研制现状及与国外的差距做了概述与展望.     

Deformation Behavior of the Zr_(53.5)Cu_(26.5)Ni_5Al_(12)Ag_3 Bulk Metallic Glass Over a Wide Range of Strain Rate and Temperatures

The stress–strain relations for the Zr53.5Cu26.5Ni5Al12Ag3 bulk metallic glass(BMG) over a broad range of temperatures(room temperature to its supercooled liquid region) and strain rates(10-4to 10-1s-1) were established in uniaxial compression using a thermal-mechanical simulation system. The superplastic flow was seen above its glass transition temperature(Tg = 694 K) and strain rates of up to 10-1s-1from the variation of stress–strain curves. A deformation map of strain rate vs temperature of Zr53.5Cu26.5Ni5Al12Ag3 was obtained, which was mainly composed of homogeneous and inhomogeneous deformation regions,the former featuring either Newtonian or non-Newtonian flow while the latter characterizing linear elastic behavior followed by shear localization, respectively. A phenomenological constitutive equation used to describe a master curve of viscosity with respect to the strain rate was obtained by fitting the experimental results, which determines the viscosity of the present alloy at the temperature near and above Tg. The results show the Zr53.5Cu26.5Ni5Al12Ag3 BMG is the subject suitable for net shape forming process at the supercooled liquid region.     

Friction Stir Welding of Zr_(55)Al_(10)Ni_5Cu_(30) Bulk Metallic Glass to Crystalline Aluminum

The Zr55Al10Ni5Cu30 bulk metallic glass plate were successfully welded to crystalline aluminum plates by using a friction stir welding (FSW) method. The welded zone was examined. No defects, cracks or pores were observed and no other crystalline phases except for aluminum were found in the welded joint. The strength of the joint is higher than that of aluminum. The glassy phase in the stir zone keeps the amorphous state, showing a successful welding. The storage modulus softens over the glass transition. An...     

FN-2合金及其在催化裂化装置波纹管中的应用

概述了耐高温、耐腐蚀的FN 2合金的基本性能及实际应用情况 ,认为FN 2合金是替代 18 8型奥氏体不锈钢用来制造波纹管的理想材料 ,可有效地防止波纹管的腐蚀破坏。