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1.
为获得性能良好的镍铁钨合金镀层,研究了镀液pH值、温度、电流密度、稳定剂抗坏血酸浓度对镍铁钨合金镀层成分和镀层沉积速率、显微硬度的影响。结果表明:镀液pH值对镀层W含量和镀层沉积速率影响较大;镀液温度对镀层沉积速率、镀层成分和镀层硬度影响均较大;随抗坏血酸浓度增加,镀层沉积速率逐渐降低,镀层表面形貌更加粗糙。在镀液pH=4,温度60℃,电流密度4A/dm~2,抗坏血酸浓度3 g/L时,镀层沉积速率和镀层的显微硬度较高,表面光亮致密,耐蚀性好。  相似文献   

2.
利用正交试验,选择温度、主盐浓度等4个因素,通过极差分析,确定了S135钻杆钢电沉积Fe-Ni-W合金镀层的最佳制备工艺,研究了镀液pH值、电流密度以及柠檬酸钠对镀层的组分、显微硬度和沉积速率的影响。结果表明:在本试验的制备条件下,获得的合金镀层结构为非晶态;随着镀液PH升高,镀层显微硬度先增大后减小,沉积速率总体呈下降趋势;镀层沉积速率随电流密度增加也逐渐增大,当电流密度从6 A/dm2增大到15 A/dm2时,合金硬度增加趋势较大,从320 HV到540 HV;当增加镀液中的柠檬酸钠含量,铁和钨均呈现增加趋势,而镍含量却出现下降趋势,同时,镀层硬度先增大后减小,沉积速率逐渐减小。  相似文献   

3.
选择对Ni-W合金电沉积影响较大的钨酸钠浓度、电流密度、镀液pH值、温度等4个工艺参数进行对比实验,探索了各因素对沉积速率、显微硬度、镀层外观的影响,为制备Ni-W合金纳米晶提供依据,同时制备出了晶粒尺寸为10.09nm的Ni-W合金纳米晶镀层。  相似文献   

4.
以镀层硬度和镀层外观为指标,研究电流密度、镀液中WC的含量、pH值、沉积温度对考察指标的影响.利用正交试验确定了电沉积最佳工艺条件:在超声振荡下,控制电流密度为7 A/cm2,施镀温度50℃,镀液中WC的含量为20 g/L,镀液pH值为5.0时,镀层硬度和镀层外观最佳,同时对Ni-W-B镀层、Ni-W-B-WC镀层的硬度、抗高温氧化性、耐腐蚀性能、表面形貌、镀层结构与成分等进行了测试.结果表明,Ni-W-B-WC复合镀层的综合性能要高于Ni-W-B合金镀层.  相似文献   

5.
采用直流电沉积法,在低碳钢表面成功沉积Ni-W-P镀层。应用X射线荧光(XRF)、扫描电子显微镜(SEM)、俄歇电子能谱(AES)、X射线衍射(XRD)仪等方法,研究电流密度、镀液pH值和镀液温度对Ni-W-P镀层成分、表面形貌和结构的影响。结果表明,电流密度和镀液pH值的变化对Ni-W-P镀层成分的影响很大,而电流密度、镀液pH值和温度对镀层厚度的影响较小。电流效率随着电流密度和镀液温度的增大分别降低和升高,而随着镀液pH值的变化,在pH=7.0时有极大值。镀液pH值对Ni-W-P镀层结构有较大影响,在pH=8.0时,镀层呈现明显的Ni(111)峰,此时镀层硬度达到极大值7130MPa。在此基础上,对Ni-W-P镀层的电沉积机制做了进一步探讨。  相似文献   

6.
目的获得电沉积Ni-Cr泡沫合金的最佳工艺参数。方法采用正交实验法研究镀液成分等工艺参数对镀层沉积速率、厚度以及合金中Cr含量的影响,并利用扫描电子显微镜等测试手段对镀层横截面厚度等镀层指标进行了考察。结果阴极电流密度为28 A/dm2,镀液pH值为2.0,镀液温度为25℃,CrCl3·6H2O的质量浓度为125 g/L,配位剂与Cr3+摩尔比为1.8时,电沉积60 min能够获得表面光亮平整的Ni-Cr合金镀层,镀层厚度为24.09μm,沉积速率为0.4198 mg/(cm2·min),镀层中Cr的质量分数为14.76%。结论镀液温度在25~40℃范围内,对Ni-Cr合金镀层厚度、沉积速率的影响最大;镀液中CrC13·6H2O浓度、配位剂与Cr3+的摩尔比两个因素,对合金镀层中Cr含量的影响较大。  相似文献   

7.
电化学沉积Ni-W合金纳米晶镀层的组织与硬度研究   总被引:1,自引:0,他引:1  
采用电沉积制备Ni-W合金纳米晶镀层,研究了纳米晶的形成与镀层组织结构和硬度。随着镀液组分的变化,镀层的表面形貌发生变化;X射线衍射结果表明,Ni-W合金的晶粒尺寸在17-30m之间;镀液组成、pH值、电流密度、温度等因素对Ni-W合金纳米晶沉积层的硬度都有影响,最主要的影响因素是pH值及电流密度。  相似文献   

8.
采用复合电镀技术,在黄铜表面制备高硬度的Ni-P-α-Al2O3纳米复合镀层,研究了阴极电流密度、纳米α-Al2O3添加量、镀液pH值、镀液温度和电镀时间对镀层硬度的影响。结果表明:当镀液温度为45℃,阴极电流密度为4A/dm2,镀液pH值为4.0,电镀时间为40min,镀液中纳米α-Al2O3的质量浓度为10g/L时,所得镀层均匀、细致、平滑,经适当热处理后,显微硬度可达到1 332HV。  相似文献   

9.
采用电沉积技术制备了Ni—W,Ni—Fe合金纳米晶,选择主盐浓度、电流密度、镀液pH值、温度等4个工艺参数进行正交试验,通过极差分析,探索了多因素对沉积速率的影响,并对Ni—W,Ni—Fe合金纳米晶镀层的组织结构和显微硬度进行评价。结果表明:通过控制主盐浓度和操作条件,可以获得不同成分的Ni—W,Ni—Fe合金纳米晶;主盐钨酸纳对于Ni—W合金沉积影响最大,而硫酸铁对Ni—Fe合金沉积影响极小;两种合金纳米晶镀层具有较高的硬度,且表面光亮,与基体结合牢固。  相似文献   

10.
采用化学沉积的方法,在低碳钢表面上制备Ni-Cu-P三元合金镀层,研究了镀液组成和操作条件对镀层沉积速率和显微硬度的影响,确定了最佳工艺条件为:硫酸镍30g/L,次亚磷酸钠15g/L,硫酸铜3.5g/L,pH=9,95℃,负载因子0.48dm2/L,醋酸钠20g/L,柠檬酸三钠60g/L,沉积时间2h,采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对镀层进行表征.结果表明:所得的化学镀层为非晶态,经过400℃热处理后镀层晶化.镀层的沉积速率和显微硬度随硫酸铜浓度、次亚磷酸钠浓度及pH值的增加先增后减,随温度的升高而增加.  相似文献   

11.
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   

12.
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   

13.
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   

14.
《中国铸造》2014,(6):537-538
The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.  相似文献   

15.
《中国铸造》2014,(6):542-546
China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society (FICMES) each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.  相似文献   

16.
正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.  相似文献   

17.
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   

18.
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   

19.
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   

20.
The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.  相似文献   

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