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《稀土》2016,(5)
首先采用二步熔炼法制备了铸态Mm(NiCoMnAl)_5-Mg_2Ni复合储氢合金,然后在不同快淬速度下对铸态Mm(NiCoMnAl)_5-Mg_2Ni复合合金进行快淬处理,获得一系列不同快淬速度的快淬态Mm(NiCoMnAl)_5-Mg_2Ni复合储氢合金。利用X射线衍射(XRD)、扫描电镜及能谱分析(SEM/EDS)和电化学测试方法研究了所有合金的微结构和电化学性能。微结构分析表明,铸态Mm(NiCoMnAl)_5-Mg_2Ni复合合金由LaNi_5和少量的Mg_2Ni相组成。而铸态复合合金经快淬处理后,合金中少量的Mg_2Ni相消失,同时有LaNi_3和极少量的La2Ni3新相形成。快淬态合金中的Mg元素主要以固溶形式优先存在于富稀土LaNi_3相中,形成(La,Mg)Ni_3相。电化学分析表明,恰当的快淬处理能使Mm(NiCoMnAl)_5-Mg_2Ni复合合金的活化性能、最大放电容量、放电特性和循环稳定性得到改善。但快淬速度太大,上述性能均有变坏趋势。当快淬速度为15 m·s-1时,Mm(NiCoMnAl)_5-Mg_2Ni复合合金具有最大的放电容量,此时合金的最大放电容量为303.5 m Ah·g~(-1),比铸态合金的最大放电容量增大了3.3%;快淬速度为20 m·s~(-1)时,复合合金的循环稳定性最佳,80次循环后的容量保持率为98.3%,比铸态合金的容量保持率增大了11.9%。 相似文献
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测试了AB3型贮氢合金La0.67Mg0.33(NiCo)3铸态与快淬态的电化学性能,用XRD和SEM测试了合金的微观结构,研究了快淬对AB3型贮氢合金电化学性能的影响.结果表明,快淬使合金的放电容量降低,对合金的活化性能没有明显影响;快淬降低了合金的容量衰减率,提高了合金的循环寿命,其主要原因是快淬使合金的晶粒显著细化.铸态和快淬态合金均具有多相结构,包括斜六面体的(La,Mg)Ni3相,六方的LaNi5相及少量的LaNi2相.快淬使合金中的LaNi2相含量增加,这是快淬使合金放电容量下降的一个主要原因. 相似文献
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《稀有金属》2017,(12)
利用快淬法制备了La_4MgNi_(19)储氢合金,并对快淬合金进行了退火处理,对比研究了快淬及其退火合金组织结构、储氢性能的差异,并对其失效行为进行了分析。结果表明,快淬La_4MgNi_(19)合金由(La,Mg)_2Ni_7,(La,Mg)_5Ni_(19)和LaNi_5多相组成,退火使晶粒尺寸变大并促进了(La,Mg)_5Ni_(19)相含量的增加。退火处理提高了快淬合金的最大放电容量和高倍率放电性能,但降低了合金的电化学循环稳定性。浸泡试验表明退火能够提高合金的本征耐腐蚀性。然而气态吸放氢循环实验后的粒度分析发现退火加剧了合金的粉化。快淬合金具有优异的抗粉化能力,在30次气态循环实验中合金粒度几乎不变,这是快淬合金电化学循环稳定性更好的主要原因。透射电镜(TEM)分析表明退火合金粉化加剧的原因在于退火过程中形成了大量的显微台阶,显微台阶之间的结合较弱,容易开裂;此外,退火过程中合金发生了部分氧化,在晶界处引入了氧化物质点,弱化了晶界的结合力。 相似文献
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实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。 相似文献
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<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic 相似文献
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正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field, 相似文献
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《China Nonferrous Metals Monthly》2014,(10)
正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF 相似文献
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《China Nonferrous Metals Monthly》2014,(10)
正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure 相似文献
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《China Nonferrous Metals Monthly》2014,(10)
正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year, 相似文献
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《China Nonferrous Metals Monthly》2014,(12)
正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform. 相似文献
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正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness. 相似文献