高丰度稀土添加对NdFeB微观结构及性能影响

钕铁硼磁体制造过程中速凝铸片微观组织的形态对磁体的性能有重要的影响。本文系统研究了不同Y\La\Ce添加量对烧结NdFeB磁体的铸片微观组织及磁体性能的影响。结果表明Y\La\Ce添加量为10%稀土总量(TRE)时,磁体速凝铸片的微观形貌保持良好的板条状结晶,而随着添加量的增加,速凝铸片的结晶形态变差,磁体性能呈线性下降。不同的取代元素对磁体性能影响程度不同,剩磁衰减量YCeLa,矫顽力衰减量YLaCe,为制备具有良好性能的低成本磁体提供了指导。     

烧结钕铁硼镀镍防腐性能比较

采用不同浇铸工艺和破碎工艺制备三种烧结钕铁硼磁体,对三种磁体及其电镀镍后的防腐性能进行了比较.研究发现,三种磁体电镀镍后的防腐性能不仅与镍镀层厚度有关,同时也与基体本身耐蚀性能有关.经对比分析,采用速凝薄带配合氢气破碎工艺制备的镀镍磁体防腐性能最佳.     

高Ce 含量的速凝带及其磁性能

近年来，Nd-Fe-B磁体需求量的与日俱增间接地造成了稀土Ce 金属的大量积压，为提高稀土Ce 的利 用率，并降低Nd-Fe-B磁体的生产成本，可采取双主相合金法制备（Nd, Ce）-Fe-B磁体，为解决上述难题提供 了一种有效途径。通过对高Ce 含量速凝带的成分及速凝工艺的探索，成功制备出了具有较好枝晶且几乎 不含α-Fe 相的Ce-Fe-B 和（Nd, Ce）-Fe-B 速凝带。在制备的烧结磁体中，（Nd, Ce）-Fe-B 磁体的剩磁达到了 11.33 kGs，Ce-Fe-B磁体的剩磁达到了8.037 kGs，为后期制定制备高Ce 含量的高性能双主相磁体的热处理工 艺提供了数据参考。     

不同工艺制备烧结NdFeB磁体的显微组织和磁性能研究

研究了利用速凝(SC)工艺以及速凝工艺结合氢破碎(HD)工艺制备NdFeB磁体的性能和微观结构。结果发现,单独引入SC工艺虽然保证了母合金α-Fe不析出,其成分不发生偏析,但是由于其特殊的微观组织结构,利用机械破碎的方法制粉容易使粉末多以多晶的状态出现,这不仅使磁体取向度降低,并使烧结磁体主相晶粒内分布有大量富钕相,这种现象必然影响到磁体的矫顽力。把SC工艺和HD工艺结合起来,可以有效地解决这个问题。     

烧结温度对NdFeB磁体组织与性能的影响

采用速凝薄带加氢破碎法制备了烧结NdFeB永磁体,通过光学显微镜、扫描电镜以及AMT—4磁学特性测量仪表征了磁体的组织和性能,考察了烧结温度对磁体组织和性能的影响规律。结果表明:随着烧结温度的升高,磁体的致密度升高,剩磁、矫顽力、最大磁能积先增大后减小,其原因是随着烧结温度的升高,主晶相晶粒长大,富钕相分布更加均匀;当烧结温度超过某一值时,磁体的组织不均匀,富钕相发生团聚。     

电弧离子镀ZrN/TiN涂层对烧结NdFeB的耐腐蚀及磨损性能的影响

为了提高粉末烧结磁体NdFeB的耐腐蚀性能和耐磨损性能,采用电弧离子镀的方法在其上沉积制备了ZrN/TiN多层涂层。观察涂层的成分与显微组织,分析了涂层对烧结磁体耐腐蚀性能及磨损性能的影响。结果表明:电弧离子镀氮化物多层涂层与烧结磁体生成一过渡层,膜基结合强度高;涂层提高了磁体的耐腐蚀倾向,降低了腐蚀电流,腐蚀速率降低2个数量级;磁体在5%盐水中10h后才出现失重,涂层保护效果明显;磁体表面涂层的硬度15～20GPa,摩擦系数0.5,耐磨损性能提高。     

粘结磁体助剂对模压成型NdFeB粘结磁体性能的影响

采用模压设备制备了NdFeB粘结磁体,并研究了粘结助剂(粘结剂和偶联剂)对快淬NdFeB粘结磁体力学性能,包括密度和抗压强度以及磁性能的影响.研究结果表明,添加偶联剂可以提高粘结磁体的性能.使用E-51环氧树脂粘结剂所获得的磁体密度、剩磁、矫顽力、最大磁能积以及抗压强度比用E-44粘结剂的磁体性能要高.随着粘结剂含量的增加,磁体的密度在逐渐降低,磁体的抗压强度在不断变大.而剩磁随着粘结剂含量的增加在不断下降.对矫顽力这个性能来说,1.5%的粘结剂含量为最佳用量.     

稀土含量对烧结NdFeB磁体磁性能及力学性能的影响

研究了不同稀土含量的烧结NdFeB磁体的磁性能、微观结构和抗弯强度。结果表明,提高稀土含量可提高烧结NdFeB磁体的抗弯强度,同时对烧结NdFeB磁体的矫顽力和退磁曲线方形度有一定的提高作用,但会降低烧结NdFeB磁体的剩磁。SEM微观形貌图像表明,提高稀土含量可有效改善铸片、烧结NdFeB磁体的微观结构,使富稀土相分布更加均匀连续,从而提高烧结NdFeB磁体的抗弯强度和矫顽力。     

重稀土掺杂烧结钕铁硼磁体的晶界调控研究进展

随着低碳经济的提出,烧结钕铁硼磁体作为新能源汽车及其他高新技术的核心材料越来越受到人们的关注,同时对其性能也提出了更高的要求,高矫顽力、高剩磁和大磁能积的永磁体成为人们追求的目标。烧结钕铁硼磁体的磁性能与微观结构中晶界成分、分布以及体积分数等密切相关。利用新型工艺在合金中掺杂重稀土可以很好地调控磁体的微观结构,从而在保持剩磁不变的基础上,提高磁体的矫顽力和磁能积。本文在详细介绍两种新型掺杂技术的基础上,梳理了近几十年来国内外通过掺杂重稀土金属、重稀土化合物及重稀土合金来调控磁体晶界结构、提高磁体矫顽力方面的最新研究成果,为进一步提高烧结钕铁硼磁体性能提供参考。     

铽镝铁合金制备烧结钕铁硼的研究

以铽镝铁合金或镝铁合金+金属铽为原料,采用相同的熔炼设备和工艺,制备高性能烧结钕铁硼。对比了配料比例相同但加入方式不同所得速凝铸片的厚度分布、化学成分、显微组织、毛坯磁体磁性能,进一步考察了降低铽含量之后磁体磁性能的变化。钕铁硼合金成分设计为RE(Pr,Nd,Tb,Dy)_(32.6)M(Fe,Co,Al,Ga,Cu,Nb,Zr)_(bal)B_(1.0)(质量分数)。研究结果表明,两种原料加入方式获得的速凝铸片外观、厚度分布、显微组织无明显变化,但以铽镝铁合金加入方式得到的速凝铸片中铽的有效成分提高10.71%,制备的毛坯矫顽力提高14.04%,而剩磁略低。以铽镝铁合金为原料,但铽的用量比镝铁合金+金属铽原料降低10%,制备的毛坯磁性能与后者制备的相当,从而大大节约了稀土资源。     

Chinalco Signed Framework Agreement for Strategic Cooperation with Harbin Municipal Government

正Last month,Chinalco signed framework agreement for strategic cooperation with Harbin Municipal Government in Harbin Xiong Weiping,Chairman of Chinalco,said that based on the strategic deployment to build world top-class mining company with the highest growth potential,Chinalco was now concentrating all efforts on making strategic transition and structural adjustment,strategic cooperation with the local governments where     

Jiangxi Promotes Jiangxi Copper Corporation To Become The World's Most Competitive Mining Company

<正>According to the latest info from Jiangxi Province State-owned Assets Supervision and Administration Commission,Jiangxi Copper Corporation was approved to become the first pilot enterprise for deepening reform.Contents of the pilot work is"Three Self"(self expansion,self decision-making,self     

Journal of Rare Earths Contents List of Vol.32(2014)

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Contributions to Baosteel Technical Research wanted

正Baosteel Technical Research,a quarterly journal,which is issued domestically and abroad,is run and sponsored by Baosteel Group Corporation.Baosteel Technical Research mainly reports the achievements in technological innovation,academic research,new product development and industrial equipment improvement by Baosteel.It will continue to follow up on hot topics and serve the company’s technological development and progress.Its readers include experts in     

Ministry of Industry and Information Technology: No Short Term Solution For Our Country’s Excess Nonferrous Metal Smelting Capacity

【正】According to the Ministry of Industry and Information Technology,the Ministry has released the 2013 Operation Report on China’s Industrial Communication Indu...     

Chinalco Signed Framework Agreement for Strategic Cooperation with Gansu Province

正Recently,Chinalco and Gansu Provincial People’s Government signed"Framework Agreement for Strategic Cooperation on Reform,Restructuring and Transition Development of Chinalco’s Electrolytic Aluminum Enterprises in Gansu",signifying that the strategic cooperation between Chinalco and Gansu Province had made new substantive progress.     

Unavoidable Economic Cycle:30% Of Nonferrous Metal Companies Were Involved In Restructuring

正Owing to continual downturn in real estate and bulk commodity markets,a number of traditional industries in China suffered unfavorable impact in performance.With the progressive disclosure of third quarter report,the no-pleasant-surprise performance of     

Baotou Rare Earth Became the World's Biggest High Performance Magnetic Material Base

正The High Performance Magnetic Material Phase II Project,an industry upgrading project implemented by Inner Mongolia Baotou IronSteel Rare Earth(Group)Hi-tech Co.,Ltd,recently basically finished equipment commissioning,signifying that the enterprise had developed the production capacity of15000 t/a Nd-Fe-B strip casting alloy and 5000t/a Nd-Fe-B magnet,thus becoming the world’s     

Introducing Two Central Enterprises to Integrate Rare Earth Industry,Shandong Rare Earth Group Breaks Surface

正With the signing of"Letter of intention for Propelling Integration of Shandong Rare Earth Enterprises"between Shandong Province Commission Of Economy and Informatization,China IronSteel Research Institute Group("China Steel Institute"),and China Rare MetalsRare Earth Co.,Ltd("China Rare Earth"),the"Shandong Rare Earth Group"jointly set up by the 3 units thus broke surface.On August 9,reporters of the China Economic Herald learned from Shandong Province     

Aluminium Production by Province or City in 2014

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