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用化学镀的方法制备Fe-P合金, 分析化学镀层在1 mol/L NaOH介质中的腐蚀行为。试验结果表明, 镀液pH值的变化引起化学沉积速率的变化, 随着镀液pH值的增大, 化学镀铁的沉积速率先增后降; 不同pH值镀液所制备的镀层在NaOH溶液中腐蚀电位存在差异, 这可归于镀层中磷含量的不同; 电化学测试表明, 镀层试样在NaOH溶液中的极化曲线上出现若干个阳极电流峰, 表明多个阳极反应的存在, 镀层发生氧化反应生成铁的氧化物或氢氧化物; 循环伏安曲线中阴、阳极峰电流的不同以及不同扫描速度下峰电位的变化, 说明镀层的腐蚀反应为不可逆反应。 相似文献
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Co-B_4C复合镀层耐磨性能研究 总被引:1,自引:1,他引:0
采用复合电沉积技术在45钢基体上制备了Co-B4C复合镀层,对复合镀层的截面形貌和组织结构进行了观察分析,研究了镀液中B4C颗粒含量对复合镀层的显微硬度和摩擦磨损性能的影响。研究结果表明,B4C颗粒均匀地分布于Co基金属中,镀层与基体结合良好,无孔隙和裂纹等缺陷,镀态下镀层为晶态结构;随着镀液中B4C颗粒含量的增加,镀层的显微硬度和耐磨性也逐渐提高,且当镀液中B4C颗粒含量分别为20 g/L、15 g/L时,镀层的显微硬度和耐磨性达到最高值。 相似文献
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为改善YG6硬质合金与合金钢之间的钎焊性能,在YG6合金表面制备了化学镀Ni-P镀层,主要研究了pH值、温度及添加剂含量对镀速、镀层结构以及钎料润湿性的影响。结果表明,随着镀液pH值升高,化学镀镀速先增加后降低,镀层对焊锡润湿性先增加后降低;随着镀液温度升高,化学镀镀速和镀层对焊锡润湿性逐渐增加;随着添加剂含量升高,化学镀镀速增加,镀层的表面粗糙度和对焊锡润湿性先都出现先增加后降低的趋势。最佳的镀覆工艺参数为:p H=9、温度80℃、添加剂含量1.5 g/L,获得的镀层组织均匀致密,与焊料润湿性好。 相似文献
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以微机控制电化学分析系统对铵盐镍基胎体镀层的电化学机理进行研究,试验了硫酸镍用量、氯化铵用量、镀液温度和镀液的pH值对镍沉积的影响,结果表明保持镀液适当高的pH值、略低的温度和加入氯化铵,可使镍沉积的极化增大,从而使镀层晶粒变小,结晶致密,且氯化铵的加入没有改变阴极过程的控制步骤.在NiSO4*6H2O 280 g/L,NH4Cl 19 g/L,H3BO3 35 g/L,十二烷基硫酸钠0.1 g/L;镀液温度45 ℃±1 ℃,pH值5.2,电流密度3.6 A/dm2条件下电镀41/27 mm室内钻头,钻进可钻性Ⅷ级的绢云母化含石英斜长石玢岩,钻进时效平均达到1.94 m/h,钻头的磨损约为0.092 mm/m,与普通镍-钴胎体钻头的使用寿命相差不大;但其钻进时效要比镍-钴胎体钻头高0.18 m/h,即约高10%,为野外生产试验提供了试制钻头的可靠资料和经验. 相似文献
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在高压釜中用硫铁矿还原硫铁矿烧渣与硫酸反应所得酸浸液中Fe3+,当酸浸液组成为c(Fe3+)=2.6525 mol/L、c(Fe2+)=0.1125 mol/L、c(H+)=1.2300 mol/L、反应温度为250℃、液固比为251、反应时间为30 min时,Fe3+还原率达到100%.酸浸液pH≤0时,产生灰色FeSO4·H2O沉淀物;酸浸液pH≥0.5时,有碱式盐Fe2(SO4)2(OH)·5H2O和复盐Na3Fe(SO4)3·H2O等沉淀物生成.该方法制备所得绿矾样品质量好于GB 10531-89优等品,并且具有工艺简单、反应速度快,还原率高等优点. 相似文献
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为进一步扩大超轻LA141镁锂合金的应用范围,提高其表面硬度、耐蚀性和耐磨性,采用化学复合镀的方式在LA141镁锂合金表面制备Ni-P/nano-Al2O3复合镀层,主要研究了搅拌速度对复合镀层物相结构、微观形貌、硬度、耐蚀性和耐磨性的影响。结果表明:随着搅拌速度的增加,复合镀层表面的纳米粒子沉积量先增加后减少,其硬度、耐蚀性和耐磨性同样呈现出先增加后减小的趋势。当镀液搅拌速度为600 r/min时,复合镀层的耐蚀性最好,其腐蚀电位和腐蚀电流密度分别为-0.502 V和3.85×10-5 A/cm2;当镀液搅拌速度为800 r/min时,复合镀层的纳米粒子沉积量最多,耐磨性最好,其摩擦系数在0.45~0.55之间,磨痕宽度约为750 μm。 相似文献
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Bai Wenping 《中国稀土信息(英文版)》2014,(12)
<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH 相似文献
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《中国稀土信息(英文版)》2014,(9)
正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to 相似文献
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<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth 相似文献
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《中国稀土信息(英文版)》2014,(6)
正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products 相似文献
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YANG Li 《中国稀土信息(英文版)》2014,(6)
<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy 相似文献
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Gao Wei 《中国稀土信息(英文版)》2014,(11)
正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium 相似文献
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《中国稀土信息(英文版)》2014,(8)
正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared 相似文献
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《中国稀土信息(英文版)》2014,(12)
正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow. 相似文献
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《中国稀土信息(英文版)》2014,(8)
正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets. 相似文献