添加不同钐含量的Sm2Fe17型合金及其氮化物的研究

通过采用粉末冶金法及密封氮化的方法，对添加不同钐含量的Sm2Fe17型合金及其氮化物的组织形貌、物相组成与结构及磁性能进行了研究。结果发现，多补偿添加25％钐可以使Sm2Fe17型合金退火态的α—Fe含量小于2％。Sm-Fe合金冶炼后的主相均表现为菱方Th2zn17型结构，但快冷时优先沿{300}和{220}面长大。氮化后Sm2Fe17晶格膨胀形成Sm2Fe17N，主相，而α—Fe的X射线特征峰未见明显移动。Sm14．2FeB58合金晶胞膨胀相对较小，而Sm12.8Fe87.2晶胞膨胀较大，在氮化20h时有最大△V／V=8．36％：氮化增加合金中的α—Fe含量。Sm14．2Fes5．8N，的剩磁最高为59．5Am^2／kg，S1l0．5Fe89.5Nx磁化强度最高值为193．6Am^2／kg，Sm12．8Fe87．2Nx合金的所有磁性能值基本分布在Sm14．2Fe85．8Nx和Sm10．5Fe89．5Nx的值之间。     

HDDR法制备各向同性SmFeN永磁体的研究

研究了HDDR法制备各向同性Sm2Fe17Nx磁体的制备、结构与磁性能,发现SmFe铸态组织主要由Sm2Fe17、SmFe2、SmFe3和α-Fe四种相组成,而经过1050℃均匀化退火13h后形成了所需要的接近单相组织的Sm2Fe17相合金。铸锭经过粉碎球磨、HDDR、渗氮处理后,经压制成型得到各向同性的高矫顽力的Sm2Fe17Nx磁体。获得的磁体矫顽力达到了1300kA/m。     

放电等离子烧结技术制备Sm2Fe17Nx烧结磁体的研究

采用放电等离子烧结技术制备了Sm2Fe17Nx烧结磁体,考查了压力、烧结温度和升温速率对烧结磁体性能的影响.结果表明:随压力的增加,磁体的致密度显著提高,但Sm2Fe17Nx分解成SmN、α-Fe和N2的程度加剧,造成磁体的矫顽力明显下降,在1GPa的高压下烧结时,超过200℃后磁体的矫顽力就下降很快,说明高压促进了Sm2Fe17Nx的低温分解;采用升温速率为450℃/min的快速烧结工艺,发现未能有效地抑制Sm2Fe17Nx的分解.     

Sm2(Fe,M)17Nx稀土永磁材料的研究进展

综述了Sm2(Fe，M)17Nx永磁材料的最新研究进展，介绍了Sm2(Fe，M)17Nx磁粉及磁体的制备技术，说明用其他元素替换Sm或Fe对材料性能的影响，以及粉末颗粒具有最佳的尺寸和形貌的重要性。并指出放电等离子烧结技术(SPS)有望成为制备Sm2(Fe，M)17Nx致密磁体的一个有效方法。     

还原扩散法制备Sm2Fe17Nx磁粉的研究

研究了还原扩散法制备Sm2Fe17Nx磁粉过程中,还原扩散反应温度和时间对Sm2Fe17合金单相性的影响,以及Sm2Fe17合金渗氮过程中渗氮温度和时间对Sm2Fe17Nx磁粉性能的影响.结果表明当还原扩散反应温度为1423K、反应时间为5小时能得到均相单一的Sm2Fe17合金;在728K温度下渗氮3.5小时后,400目～500目的Sm2Fe17Nx磁粉的各项磁性能达最大值Br=0.8943T,Hc=325.8kA/m,Hcj=420.3kA/m,(BH)max=78.6kJ/m3.     

M型铁氧体(Ca0.50La0.45Sr0.05)Fe11.25Co0.35Oα磁粉及磁体的制备

采用粉末冶金工艺制备了主相组成为(Ca0.50La0.45Sr0.05)Fe11.25Co0.35Oα的M型永磁铁氧体磁粉,研究了磁粉在预烧过程中的相成分及由此磁粉制备的各向异性烧结磁体的磁性能.结果表明,最终获得的预烧磁粉由M型永磁铁氧体相和α-Fe2O3相组成,制备的烧结磁体中含有Fe2+.永磁体的磁性能为:Br=...     

急冷Sm-Fe合金的显微结构及其氮化的研究

采用熔体急冷法,将钐含量为30%(质量分数)的钐铁母合金在高真空旋淬一体炉中进行急冷处理,制得急冷Sm Fe合金薄带。利用X射线衍射仪(XRD)、场发射扫描电镜(FE-SEM)、热重-示差扫描量热分析仪(TG-DSC)、氧氮氢联测仪等对氮化前后急冷态钐铁合金进行了显微组织和结构、氮含量的测定,分析了渗氮效果。结果表明,随着冷却速率的增加,钐铁合金薄带的微观结构显著细化。当旋淬一体炉的单辊转速超过34. 0 m·s-1,制得了一种晶体与非晶体共存的急冷态钐铁合金,由接近Sm2Fe17正成分的晶相与非晶相基体组成。对合金进行渗氮处理后发现,N原子进入到急冷钐铁合金后,形成了以Sm2Fe17Nx和α-Fe为主相的晶体与含氮非晶体共存的化合物,气体渗氮量可以达到4. 155%。这种晶体与非晶体共存的结构特征可以改善钐铁合金的渗氮效果。     

机械球磨法制备纳米晶复相Nd2Fe14B/α-Fe永磁粉末

通过将成分为Nd2Fe14B（原子比）的铸态合金与羰基铁粉的混合粉末进行搅拌式机械球磨，并对球磨后的合金粉末进行真空晶化处理，制备了纳米复相Nd2Fe14B/α-Fe永磁合金。通过X射线衍射（XRD）、差示扫描量热法（DSC）、透射电子显微镜（TEM）等分析方法研究了球磨时间及晶化处理温度对合金微观组织的影响。结果表明，随球磨时间的延长，Nd2Fe14相及α-Fe的晶粒尺寸迅速减小，球磨5h后粉末由Nd2Fe14B非晶相和晶粒尺寸约为10nm左右的α-Fe组成，在随后的晶化热处理过程中转变成Nd2Fe14B／α-Fe纳米复相组织。     

快淬钐铁合金的氮化处理

通过XRD、SEM等手段研究了快淬钐铁合金的氮化处理工艺。研究结果表明:快淬钐铁薄带经氮化后主要由Sm2Fe17Nx、α-Fe、Fe2O3和Sm2O3组成;含有非晶的快淬钐铁薄带经过氮化处理之后,发生了部分晶化,但结晶度较低或晶粒很小,没有过分长大,基本保持了快淬薄带的晶粒尺寸;渗氮后贴辊面上散落排列着清晰可见的细小晶粒,最大晶粒尺寸在5μm左右,自由面上球形颗粒的边界处杂乱地分布着含有氮化物的白色物质,且快淬速度越大的薄带上析出的白色物质越多。     

还原扩散法制备Sm2Fe17化合物的工艺研究

研究了还原扩散法制备Sm2Fe17化合物工艺中Sm2O3，Ca，CaCl2的配入量对Sm2Fe17合金均相性的影响，并用XRD对产物进行物相分析。结果表明：当反应温度为1423K，反应时间为5h，Sm2O3，Ca，CaCl2的配入量分别为121％，225％，8％时，还原扩散反应比较充分，能得到均相单一的Sm2Fe17化合物。     

熔炼次数对M17返回料合金成分、组织和性能的影响

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。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<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     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

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,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

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     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

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     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

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,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

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.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

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.