Nd8-xDyxFe82Co6B4纳米复合永磁材料的磁性能

针对NdFeB纳米复合永磁材料的矫顽力偏低的现状,采用熔体快淬法制备了Nd8DyxFe82Co6B4（x=0,0．4,0．8,1．2,1．6）纳米复合永磁材料,研究了Dy和Co的添加对NdFeB纳米复合永磁材料的磁性能的影响．研究结果表明,Dy的添加可提高材料的各向异性场,提高矫顽力,但是Dy元素的添加使材料的剩磁降低,结晶温度升高,因此添加量不宜过多;复合添加Co原子不仅可以提高材料的剩磁和矫顽力,而且可以弥补只添加Dy元素使材料的结晶温度升高的缺陷．在最佳的热处理条件下,Dy含量x=0．8时的样品表现出最佳的磁性能,矫顽力jHc=524kA／m,剩磁Br=1．11T,最大磁能积（BH）max=158kJ／m^3．     

室温磁制冷机永磁磁场的设计

根据室温磁制冷机用永磁磁场的特点,用磁库仑定律法推导出一套永磁磁路计算公式,该公式可计算各种室温磁制冷机用永磁磁路的磁感应强度(B),计算值与实际测量值符合得较好.采用聚磁技术设计了磁制冷用的大于1.8 T的永磁磁场,并根据往复式和旋转式磁制冷机的特点,设计了室温磁制冷机用的几种永磁磁场.     

NdFeB磁性材料表面化学镀Ni-W-P合金研究

通过不同的化学镀工艺配方,在NdFeB永磁体表面获得4种不同W含量的化学镀Ni-W-P三元合金镀层。利用SEM对镀层的微观组织观察与分析表明:镀层表面形貌呈致密胞状结构,Ni、W、P元素分布均匀。进一步的衍射分析和硬度测试表明:随镀层中W和P元素含量的不同,镀层结构分别由纳米晶态、混晶态和非晶态组成,镀层的硬度随镀层结构从非晶态-混晶态-晶态的转变而增加。     

Hot deformed anisotropic nanocrystalline NdFeB based magnets prepared from spark plasma sintered melt spun powders

Anisotropic magnets were prepared by spark plasma sintering (SPS) followed by hot deformation (HD) using melt-spun powders as the starting material. Good magnetic properties with the remanence J_r > 1.32 T and maximum of energy product (BH)_max > 303 kJ/m³ have been obtained. The microstructure evolution during HD and its influence on the magnetic properties were investigated. The fine grain zone and coarse grain zone formed in the SPS showed different deformation behaviors. The microstructure also had an important effect on the temperature coefficients of coercivity. A strong domain-wall pinning model was valid to interpret the coercivity mechanism of the HDed magnets. The increase of stray field and weakening of domain-wall pinning effects were the main reasons of the decrease of the coercivity with increasing the compression ratio. The influences of non-uniform plastic deformation on the microstructure and magnetic properties were investigated. The polarization characteristics of HDed magnets were demonstrated. It was found out that the HDed magnets had better corrosion resistance than the counterpart sintered magnet.     

Preparation of Ni–Co alloy coating on sintered NdFeB magnet by potentiodynamic electrodeposition

A protective Ni–Co alloy coating was successfully prepared on sintered neodymium–iron–boron (NdFeB) magnet via potentiodynamic electrodeposition in this paper. The microstructure and surface morphology analysis of Ni–Co alloy coating showed that the surface morphologies were quite compact and more uniform than that prepared by direct current (DC) electrodeposition; significantly, the chemical composition analysis indicated that the content of Co in the alloy coatings amounted to 33–34?wt-%. Potentiodynamic polarisation and long term immersion test results revealed that the Ni–Co alloy coating could supply excellent corrosion protection for NdFeB substrate in 3.5?wt-% NaCl solution. Overall, the Ni–Co alloy coating with higher Co content prepared by potentiodynamic electrodeposition exhibited better corrosion protection for sintered NdFeB magnet compared with that prepared by DC electrodeposition.     

粘结钕铁硼磁体阴极电泳工艺研究

粘结NdFeB磁体极易被腐蚀,因而需要涂层保护.本文研究了粘结NdFeB磁体的阴极电泳工艺,主要是电泳电压,电泳时间,电泳时漆液温度以及涂层烘烤固化对涂层抗蚀性的影响.研究发现用合适的工艺参数所获得的涂层能够显著提高粘结NdFeB磁体的抗蚀性能.     

粉煤灰陶粒混凝土的工艺性能

多孔结构和轻质是粉煤灰陶粒的基本特征 ,它们影响混凝土拌和物的工艺性能 ,本文试验研究了陶粒混凝土拌和物的坍落度及其损失、离析性和减水剂的塑化效果。     

塑料磁体NdFeB树脂复合材料的研制

金属ＮｄＦｅＢ磁粉和聚合物混合后采用一定工艺制成的器件，既有金属粉磁的特性，又有塑料的性能，是一种新的功能性器件，本试验对该类器的制作 工艺，组织结构和磁性能关系进行进行了研究，制成的塑料磁体已成功竽各种功能性执行元件，仪器仪表，微型马达，使用效果良好。     

Effect of HD Process on Microstructure and Hard Magnetic Properties of NdFeAlB Magnet

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烧结耐火材料的超声检测

在烧结耐火材料的超声检测中,采用以判断声速为主的综合判断方法对烧结耐火砖的缺陷情况和内部结构特点进行检测判断,结果与机械化破坏后观察到的情况吻合。