树脂基磁性复合材料的软磁性能研究

研究了非晶粉体的退火温度、纳米晶粉体的含量及复合材料的退火温度对复合材料起始磁导率iμ和电感L的影响。结果表明:以经550℃×0.5 h退火的Fe73.5Cu1Nb3Si13.5B9纳米晶粉体为组元的复合材料的起始磁导率最大,电感最大;随着纳米晶粉体含量的增加,复合材料的起始磁导率增大,电感增大;去应力退火可以提高复合材料的起始磁导率。     

刹车用SiO2/Cu复合材料基体中Fe和Sn对摩擦性能的影响

在MM-1000型摩擦试验机上测试Cu-Fe，Cu-Sn，Cu-Fe-Sn三种基体的SiO2／Cu复合材料的摩擦磨损性能，通过扫描电镜观察及能谱分析讨论基体中Fe和Sn的存在状态、作用以及对材料摩擦性能的影响。结果表明，Cu-Fe-Sn基体的SiO2／Cu复合材料具有更高的摩擦系数及稳定性、更小的磨损量，可承受更高的触动速度，是适合高速制动的高性能刹车材料。     

高纯球形纳米SiO2的制备

以高纯石英为原料,采用沉淀法制备球形纳米SiO2。研究了水玻璃溶液波美度、HCl浓度、反应温度、搅拌速度对球形纳米SiO2平均粒径的影响。当水玻璃溶液波美度为10。Bé、盐酸浓度为1.0 mol/L、反应温度为80℃、搅拌速度为1300 r/min、滴定至pH值为8时,制备出初级粒径为80-90nm、粒度均匀、基本无团聚的无定形球形纳米SiO2,其DBP吸收值为2.75cm3/g,比表面积为174.01 m2/g。在1100℃高温下,对球形纳米SiO2高温处理2h,可以脱除沉淀法纳米SiO2表面的羟基,测定球形纳米SiO2粉的纯度为99.9%。     

纳米粘土/EP复合材料性能研究

采用正交方案，蒙脱石通过HDTMAB阳离子插层制备纳米粘土，冲击实验表明最佳条件为：反应温度90℃、矿浆浓度5％、反应时间2h。在EP中加入5％纳米粘土，制得的纳米粘土／EP复合材料的抗冲击强度和弯曲强度，分别比纯EP提高303．2％和45．5％。     

蒙脱石/尼龙6纳米复合材料制备及性能研究

介绍了熔体挤出法蒙脱石／尼龙6纳米复合材料制备、性能、影响因素及应用前景。将自制的改性蒙脱石同尼龙6、稳定剂、硬脂酸等混合均匀后，用双螺杆挤出机挤出造粒，制造的蒙脱石／尼龙6纳米复合材料拉伸强度84.41MPa、抗弯强度115.40MPa、热变形温度（0.45MPa)189℃。     

基于全子集回归和逐步回归的煤灰氧化物组成对熔融性影响的研究

为探究氧化物组成对煤灰熔融特性的影响，选取煤灰中的氧化物含量作为自变量，在SPSS软件平台上对变形温度DT、软化温度ST、半球温度HT和流动温度FT分别进行全子集回归和逐步回归，比较得到显著性最强的新定义的熔融指数FI和最优的回归预测方程。结果表明，单一氧化物组分对灰熔温度的影响不显著|对DT影响最显著的熔融指数为FID=Al2O3+Fe2O3，且煤灰中FID含量低于30%时，DT几乎不变化，含量大于30%时DT发生较大幅度降低|对FT影响最显著的熔融指数为FIF=SiO2+Al2O3+Fe2O3，且随着FIF含量升高，流动温度呈上升趋势|对半球温度HT影响最显著的熔融指数FIH= SiO2+Al2O3，对软化温度ST影响最显著的熔融指数FIS=SiO2+Al2O3+Fe2O3，但FIH和FIS对ST和HT的显著性略低，为得到更准确的预测模型，进一步以十种氧化物为起点通过逐步回归方法分析得到ST和HT的预测方程。     

WC颗粒增强铜基复合材料的研究

用粉末冶金法制备了WC增强的WC／Cu复合材料，研究了WC含量对复合材料性能的影响，分析了复合材料的再结晶行为，结果表明：WC体积含量为1.6％时，细小的WC粒子均匀分布，弥散效果好，材料的密度为8．41g／cm^3，硬度为HV151，电导率为85％IACS，其综合性能较优；WC粒子能显提高复合材料的再结晶温度。图6，表1，参10．     

纳米SiO2改性PP/微晶白云母复合材料的研究

利用熔融共混的加工工艺制备PP/微晶白云母/纳米SiO2复合材料,考察了不同处理方法及用量的纳米Si2、微晶白云母对PP基体的影响,结果表明:用硅烷偶联剂表面处理纳米Si2、微晶白云母,并用马来酸酐接枝聚丙烯(PE-g-MAH)做相容剂,当PP/微晶白云母/纳米SiO2为100/30/1时,复合体系的综合力学性能最优.通过扫描电镜(SEM),对复合材料的微观结构进行了表征,证明了纳米SiO2、微晶白云母能均匀的分散于PP基体中,从而起到了良好的改性作用.     

纳米自增强复合材料的动态流变行为研究

采用动态流变学方法研究了纳米二氧化硅(SiO2)/聚丙烯(PP)复合材料的熔体流变行为.通过探讨纳米粒子接枝改性、粒子含量和制备方法对复合材料熔体动态粘弹响应的影响,研究纳米复合材料宏观流变性质与微观结构参数之间的关系.结果表明,纳米粒子表面处理、含量和加工方法对聚合物复合材料熔体的动态粘弹响应有明显影响,低频率ω区域粘弹函数对纳米复合材料的结构变化存在敏感响应.接枝改性纳米粒子的加入使复合材料的低ω区域动态储能模量(G′)与ω的对数关系lgG′～lgω出现第二平台特征,纯PP和未改性纳米粒子填充体系中未出现此现象,证实了复合材料中纳米填料网络结构的存在,且出现填料网络结构的纳米粒子逾渗值低至0.87%(体积分数),说明少量纳米粒子的加入即可引起复合材料结构和界面特性的变化.     

基于全子集回归和逐步回归的煤灰氧化物组成对熔融性影响的研究

为探究氧化物组成对煤灰熔融特性的影响,选取煤灰中的氧化物含量作为自变量,在SPSS软件平台上对变形温度DT、软化温度ST、半球温度HT和流动温度FT分别进行全子集回归和逐步回归,比较得到显著性最强的新定义的熔融指数FI和最优的回归预测方程。结果表明,单一氧化物组分对灰熔温度的影响不显著|对DT影响最显著的熔融指数为FID=Al2O3+Fe2O3,且煤灰中FID含量低于30%时,DT几乎不变化,含量大于30%时DT发生较大幅度降低|对FT影响最显著的熔融指数为FIF=SiO2+Al2O3+Fe2O3,且随着FIF含量升高,流动温度呈上升趋势|对半球温度HT影响最显著的熔融指数FIH= SiO2+Al2O3,对软化温度ST影响最显著的熔融指数FIS=SiO2+Al2O3+Fe2O3,但FIH和FIS对ST和HT的显著性略低,为得到更准确的预测模型,进一步以十种氧化物为起点通过逐步回归方法分析得到ST和HT的预测方程。     

Current situation and future trend of China rare earth luminescent material industry

<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     

China rare earth market review

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     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<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     

Market opportunities and challenges for rare earth polishing powder

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     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

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     

Market and recycling of NiMH battery

<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     

China rare earth market review

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     

2014 second batch of rare earth quota released

正~~     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586