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1.
超声波和稀土铈对化学镀Co-Ni-B合金镀层的改性作用   总被引:1,自引:1,他引:1  
利用等离子发射光谱仪、电子能谱仪、X射线衍射仪、透射电子显微镜和显微硬度计等考察和分析了引入超声波和稀土金属铈时化学镀Co-Ni-B合金镀液的沉积速度、Co-Ni-B合金镀层的化学成分、晶体结构和显微硬度。结果表明,超声波和稀土金属铈的介入明显提高了化学镀Co-Ni-B合金的沉积速度,超声波的介入则提高了化学镀Co-Ni-B-Ce合金镀层中稀土铈的含量。在超声波和稀土铈的共同作用下,化学镀Co-Ni-B合金镀层的化学组成发生了改变,镀层结构由非晶态向微晶和晶态转化,镀层的显微硬度得到了较大的提高。  相似文献   

2.
系统研究了A侧稀土元素中Ce含量对AB5犁贮氢合金La0.8(1-x)Ce0.8x(PrNd)0.2B5的结构、热力学性能、电化学性能和动力学性能的影响。结果表明:Ce含量对合金的结构基本上没有明显的影响,合金的晶胞参数a、c及晶胞体积与Ce的含量的变化呈线性关系;随着Ce含量增加,合金的吸放氢平台压力升高,滞后效应减小,吸氢量减小,合金氢化物的热力学稳定性变差:Ce含量的变化对合金的电化学活化速度影响很小,但Ce含量的增加可以明显提高合金的放电中值电位,改善合金的高倍率、高功率放电性能和动力学性能。  相似文献   

3.
在843K LiCl-KCl-CeCl3熔盐中活性铝电极上,研究了Ce(III)离子的电化学行为和欠电位沉积Al-Ce合金。对比循环伏安曲线发现,在Al电极上Ce(III)/Ce反应的氧化还原电势比在Mo惰性电极上更正;开路计时电位在金属铝和铈的沉积平台之间出现两个平台,这表明Ce(III)在Al活性电极上可以生成两种金属间化合物。以上结果在电化学机理上说明Ce(III)离子可以在Al电极上欠电位沉积形成金属间化合物。在该实验条件下通过恒电位电解,在Al电极上得到了Al-Ce合金,验证了理论分析的结果。经XRD表征,证实了形成AlCe和AlCe3两种合金;经SEM和EDS表征,证明了铈分布在Al电极表面厚度均一的合金镀层中(厚度28?m)。 关键词:LiCl-KCl熔盐;欠电位沉积;铝电极;Al-Ce合金  相似文献   

4.
肖友军 《表面技术》2005,34(5):38-39,88
为了得到性能优良的钴基软磁薄膜,利用等离子发射光谱仪、电子能谱仪、显微硬度计等考察和分析了引入稀土金属La时化学沉积Co-Ni-B的合金镀层成分、显微硬度和磁性能.结果表明:微量稀土La的加入提高了镀层中Co的含量,降低了Ni和B的含量;在一定的范围内,稀土La能明显提高合金镀层的显微硬度,饱和磁化强度,降低剩余磁化强度和矫顽力.因此,Co-Ni-B-La镀层显示了良好的软磁性能.  相似文献   

5.
利用金相显微镜和拉伸实验机,研究了不同含量的微量稀土元素Ce对铸造Al-Cu-Mn合金显微组织和力学性能的影响。结果表明:随稀土元素Ce含量的增加,合金中枝状晶呈先变小后变大;热处理后合金的抗拉强度和伸长率先增加后减小。当稀土元素Ce含量为0.1%时,合金的抗拉强度和伸长率达到最大值,分别为425 MPa和.18%。  相似文献   

6.
研究了稀土元素Y,Ce和La对Fe-25Cr-40Ni合金高温硫化的影响。当合金中稀土含量为0.1wt-%时,合金的硫化速度明显降低。Y对降低合金硫化速度的影响大于Ce和La。加入Y的合金硫化时,在硫化内层优先形成带有保护性的较致密的硫化铬,它的晶粒较细,与基体很好粘着。在硫化层结构和成分分析的基础上提出了合金加入稀土元素后的硫化机理。  相似文献   

7.
王帅  郑开宏  郑志斌  王娟  吴伟 《铸造》2018,(12):1060-1064,1067
利用Gp-Ts20 000M热模拟机对添加稀土元素Ce的K-52奥氏体耐热钢在常温(25℃)、300℃、500℃和700℃下,以2 mm/min的拉伸速度进行拉伸试验。通过分析试样的宏观变形、力学性能变化曲线和断口形貌等,研究了稀土元素Ce对试验钢高温拉伸性能的影响,并分析其断裂机理。结果表明,随着拉伸温度的提高,金属有向塑性变形转变的趋势;试验钢中添加稀土元素Ce后,提高了合金的高温力学性能,其拉伸断口中的韧窝数量增多。与未添加稀土元素的合金相比,添加稀土元素Ce的K-52合金其屈服强度、抗拉强度和伸长率分别提高了5.37%、11.69%和22.82%。  相似文献   

8.
在843 K LiCl-KCl-CeCl_3熔盐中活性铝电极上,研究了Ce(Ⅲ)离子的电化学行为和欠电位沉积Al-Ce合金。对比循环伏安曲线发现,在Al电极上Ce(Ⅲ)/Ce反应的氧化还原电势比在Mo惰性电极上更正;开路计时电位在金属铝和铈的沉积平台之间出现2个平台,这表明Ce(Ⅲ)在A1活性电极上可以生成两种金属间化合物。以上结果在电化学机理上说明Ce(Ⅲ)离子可以在Al电极上欠电位沉积形成金属间化合物。在该实验条件下通过恒电位电解,在Al电极上得到了Al-Ce合金,验证了电化学分析的结果。经XRD表征,证实形成了AlCe和AlCe_3两种合金,结合Al-Ce合金相图分析了只产生这两种合金的原因;结合开路电位计算了生成这两种合金的标准吉布斯自由能变值。经SEM和EDS表征,证明了铈在Al电极表面分布,并形成厚度均一约28μm的Al-Ce合金镀层。  相似文献   

9.
利用金相显微镜和拉伸实验机,研究了不同含量的微量稀土元素Ce对铸造Al-Cu-Mn合金显微组织和力学性能的影响。结果表明:随稀土元素Ce含量的增加,合金中枝状晶呈先变小后变大;热处理后合金的抗拉强度和伸长率先增加后减小。当稀土元素Ce含量为0.1%时,合金的抗拉强度和伸长率达到最大值,分别为425 MPa和3.18%。  相似文献   

10.
含Ce化学镀Co-Ni-B合金镀层功能特性的研究   总被引:1,自引:1,他引:1  
借助磨损试验机和振动样品磁强计等研究了稀土金属Ce对化学镀Co-NI-B合金镀层磨损体积、磁化强度、矫顽力和磁导率的影响。结果表明:稀土Ce明显地提高了Co-Ni-B合金镀层的耐磨性,随镀液中稀土铈添加量增加,合金镀层的磨损量是先降后增,在镀液里Ce=0.8g/L时最小。稀土铈影响了化学镀Co-Ni-B合金镀层的电子结构和磁矩,与非晶态的Co-Ni-B合金镀层相比,微晶结构的Co-Ni-B-&合金镀层具有较高的饱和磁化强度和磁导率,较低的剩余磁化强度和矫顽力,显示出了良好的软磁性能。  相似文献   

11.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

12.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

13.
吴玉梅  熊晓云  靳蓉  孙敬民  杨林  罗晓星 《金属学报》2005,10(10):1100-1103
目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。  相似文献   

14.
Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.  相似文献   

15.
The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).  相似文献   

16.
The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.  相似文献   

17.
The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.  相似文献   

18.
正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis  相似文献   

19.
Preface     
<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of  相似文献   

20.
The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.  相似文献   

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