钕铁硼用磁温度补偿合金的成分

通过电弧炉制备了磁温度补偿合金,利用振动样品磁强计(VSM)测试了其热磁性能,并采用X射线衍射(XRD)分析其相结构,对Fe-Ni二元合金及三元合金进行了系统的研究.结果表明对于Fe-x%Ni二元合金,当31≤x≤33时,合金由γ面心和α体心立方结构组成,当x=36时,合金为γ单相结构;Mo、Mn、Si、Al、Cr等元素降低了Fe-Ni合金的居里温度、饱和磁化强度,Cu、Co、C元素提高了Fe-Ni合金的居里温度、饱和磁化强度;元素C和Mo能显著地改变合金的居里温度、饱和磁化强度,提高合金的△B/△t最大值,有利于合金磁性能的调控.     

Si，La对Al-4．5Cu合金准固态凝固行为的影响

通过对合金的收缩应变和热裂抗力及准固态拉伸行为进行测试，研究了合金元素(Si，La)对Al-4．5Cu合金凝固行为的影响。结果表明，Si，La能使Al-4．5Cu的热裂倾向性降低；加入2％Si使合金的再辉现象非常严重，导致合金不可能有很高的强度而很快断裂：与其它Al-4．5Cu-Si合金相比，Al4．5Cu3Si合金具有很强的补缩能力，断裂应力值最高：La的加入能缩小二次枝晶间距，明显提高合金的抗热裂性能。     

Co元素及凝固速度对La-Fe-Si系NaZn13型相及磁性能影响

采用熔体快淬法制备不同快淬速度的 La0.8Ce0.2(Fe11.5-xCox)Si1.5 (x=0、0.3、0.5、0.7) 合金条带,经过 1273 K 20 min 热处理,通过 X 射线衍射和磁性测量研究 Co 元素及凝固速度对La-Ce-Fe-Co-Si的相形成和磁性能的影响。结果表明：Co 元素添加和快淬速度提高均有利于 NaZn13 型相的形成;Co 元素添加提高合金居里温度,减小磁滞,但是磁热性能有所降低;快淬速度提高导致合金的磁滞增大,但对磁热性能影响较小。     

Cu、Co元素对激光烧结CrFeNiAlSi高熵合金组织与性能的影响

采用Cr、Fe、Ni、Al、Cu、Co、Si纯金属粉末按照等摩尔比混合并压坯,激光自蔓延烧结制备CrFeNiAlSi、CrFeNiAlCuSi、CrFeNiAlCoSi高熵合金。利用OM、XRD、SEM、显微硬度计及磨粒磨损机等试验表征设备,分析了CrFeNiAlSi、CrFeNiAlCuSi、CrFeNiAlCoSi高熵合金的显微组织、物相及力学性能。结果表明:CrFeNiAlSi高熵合金主要由BCC相组成,为菊花状组织。在加入Cu、Co元素后,从单一的BCC相转化为BCC+FCC两种相共存,但仍以BCC相为主,CrFeNiAlCuSi高熵合金为菊花状+胞状组织,CrFeNiAlCoSi高熵合金为等轴晶组织。加入Cu、Co元素改变了CrFeNiAlSi高熵合金的形貌与性能,加入Cu元素后孔隙减少,硬度下降,磨损率上升。加入Co元素后硬度上升,磨损率下降,显微硬度均值为1010 HV0. 1,磨损率最小为46 mg·cm~(-2)。     

合金元素对铸造Al-4．5Cu合金准固态力学行为的影响

研究了铸造Al-4．5Cu合金的准固态力学行为及几种合金元素对其凝固行为的影响。结果表明：Si，Ce，La，Ti及Zr元素可有效减小Al-4．5Cu合金的结晶范围，从而使其热裂倾向性降低；La元素的加入可提高Al-4．5Cu合金的热裂抗力：并研制了一种新型Al-4．5Cu合金，该合金具有良好的室温与高温综合性能。     

Cu元素对Ti-16.28Si合金在900℃下氧化机制的影响

采用高能球磨一冷压一真空烧结工艺制备了Ti-16．28Si、Ti-15．46Si-5Cu和Ti-14．65Si-10Cu3种合金，并在900℃下空气气氛中对其进行高温氧化实验。通过扫描电子显微镜（SEM）、X射线能谱仪（EDS）以及x射线衍射仪（XRD）对烧结和氧化后合金样品的形貌、微区成分及物相组成进行分析，研究Cu元素对Ti-16．28Si合金在900℃下氧化机制的影响。结果表明：烧结后3种样品中主要含有Ti、Ti，Si3、Ti，Si4相，含Cu元素的样品中则出现了Cu，Si相且致密度随Cu含量升高而升高。900℃下氧化80h后，合金样品表面的主要物相为TiO2，同时含有少量的SiO2、Ti3O5、CuO或Cu2O等相。3种合金中，Ti-16．28Si合金的氧化膜表层基本上都是TiO2，抗氧化性能最好；其余2种合金的抗氧化性能稍低，Cu元素的加入降低了合金在900℃下的抗氧化性能。     

ZrCuAlSi大块非晶合金形成及力学性能

通过铜模铸造法制备(Zr47Cu44Al9)100-xSix(x=0,0.5,1.5,2.5)大块非晶合金.利用差热分析、X射线衍射、显微硬度和室温压缩试验.研究分析添加Si元素对Zr47Cu44Al9合金非晶形成能力、热稳定性及力学性能的影响.结果表明,适量Si的加入能显著提高非晶合金的热稳定性,当Si的加入量为1.5时,合金具有最大的非晶形成能力,其纯非晶试样的临界尺寸由Zr47Cu44Al9的4 mm增大到(Zr47Cu44Al9)98.5Si1.5的6 mm.Si提高非晶形成能力的原因主要是抑制了引起异质形核的CuZr相的形成与析出.力学性能实验显示,显微硬度(Hv)随Si的加入由Zr47Cu44Al9合金的5850MPa增呔到(Zr47Cu44Al9)98.5Si1.5合金的6220 MPa,(Zr47Cu44Al9)98.5Si1.5合金的断裂强度为1862 MPa.     

微量Cu元素对Au-24Ag-3.25Si钎料合金组织和焊接性能的影响

通过分析相图,配制成分分别为Au-24Ag-3.25Si、Au-24Ag-3.25Si-1.5Cu、Au-24Ag-3.25Si-2.0Cu、Au-24Ag-3.25Si-2.5Cu4种合金,中频感应真空熔铸法制备铸锭,在流动氢气保护管式电阻炉中进行焊接实验,基板采用纯Ni片,焊接温度为550℃.使用微量型DTA差热分析仪测定钎料合金的熔化温度,并通过金相观察和扫描电镜观察结合X射线能谱分析对钎料合金的组织和焊接性能进行研究.结果表明,添加适量的Cu元素能降低Au-24Ag-3.25Si钎料合金的熔点,减小固液相间隔:Cu元素的加入使Au-24Ag-3-25Si钎料合金的显微组织发生了显著变化,有新固溶体的形成,使得钎料合金的硬度随之升高;Au-24Ag-3.25Si-1.5Cu钎料合金与Ni焊接后铺展形貌良好,润湿角较小,其焊接界面组织形貌与未添加Cu元素前基本一致,仍然有金属间化合物层(IMC)出现,能谱分析和线扫描结果显示,该IMC层由Ni和Si的金属间化合物组成,Cu元素的添加没有明显改善Au-24Ag-3.25Si钎料合金与Ni的焊接性能.     

Si、Cu对Al-Mg-Si合金组织及性能的影响

通过力学性能测试、显微组织及断口分析等方法,分别研究了Si、Cu元素的加入对Al-Mg-Si合金组织及性能的影响作用,并对其随后加工工艺进行了合理探讨。结果表明:随着Si、Cu元素的增加,晶粒逐渐减小,硬度值随之增大;在相同条件下,Cu元素对铸态合金强化效果要比Si元素的作用更为显著,其主要归因于更多强化相的形成促进了结晶形核过程。通过对不同加工工艺后合金性能的比较分析,在本实验条件下合金经固溶时效、冷轧、二次时效后具有较佳的综合力学性能,其抗拉强度、延伸率分别为392MPa、11.60%。     

稀土氧化铈(CeO2)与铸态Cu-Ni-Si合金性能

在Cu—Ni—Si合金中加入稀土氧化铈（CeO2），研究稀土氧化铈（CeO2）量对铸态Cu—Ni—Si合金组织与性能的影响。结果表明：适量添加稀土氧化铈（CeO2）能显著细化铸态合金的晶粒，提高合金抗拉强度，对电导率则影响较小。在合金中添加0．06％稀土氧化铈的Cu—Ni—Si材料，铸态条件下的抗拉强度可达4uMPa，比未加稀土的合金材料的抗拉强度提高了40．7％。过量添加稀土，合金的晶粒尺寸并不能继续细化，却显著降低材料的抗拉强度。     

HIGH-TEMPERATURE AC MAGNETIC PROPERTIES OF NANOCRYSTALINE FINEMET ALLOYS WITH Co ADDITION

High-temperature AC magnetic properties for (Fe0.5Co0.5)73.5Cu1Nb3Si13.5B9 alloy annealed at various temperatures have been investigated using an impedance analyzer. Annealing temperature Ta has obvious effects on high-temperature AC magnetic properties of the alloy. The Hopkinson peak appears only in the amorphous alloy when Ta ≤ 703K. As Ta increases above 733K, the real part of the complex initial permeability μi' descends gradually, μi' decreases more slowly with temperature in the high temperature range. The high-temperature (about 750K) AC initial permeability for the alloy annealed at Ta=763K has been found to maintain a stable high value of 950 up toa frequency of～ 1 × 105Hz Partial substitution of Co for Fe in the Fe73.5Cu1Nb3Si13.5B9 alloy leads to an increase of around 110K of the Curie temperature of the amorphous phase, much higher than Ge-containing Finemet alloy.     

HIGH-TEMPERATURE AC MAGNETIC PROPERTIES OF NANOCRYSTALLINE FINEMET ALLOYS WITH Co ADDITION

High-temperature AC magnetic properties for (Fe0.5Co0.5)73.5Cu1Nb3Si13.5B9 alloy annealed at various temperatures have been investigated using an impedance analyzer. Annealing temperature Ta has obvious effects on high-temperature AC magnetic properties of the alloy. The Hopkinson peak appears only in the amorphous alloy when Ta ≤ 703K. As Ta increases above 733K, the real part of the complex initial permeability μi' descends gradually, μi' decreases more slowly with temperature in the high temperature range. The high-temperature (about 750K) AC initial permeability for the alloy annealed at Ta=763K has been found to maintain a stable high value of 950 up to a frequency of ~ 1 × 105Hz. Partial substitution of Co for Fe in the Fe73.5Cu1Nb3Si13.5B9 alloy leads to an increase of around 110K of the Curie temperature of the amorphous phase, much higher than Ge-containing Finemet alloy.     

Effects of the doping element on crystal structure and magnetic properties of Sm(Co,M)7 compounds (M=Si,Cu, Ti,Zr, and Hf)

The crystal structure and magnetic properties of Sm(Co,M)₇ (M=Si, Cu, Ti, Zr, and Hf) compounds with the TbCu₇-type structure have been investigated by means of X-ray powder diffraction and magnetic measurements. For the Sm(Co,M)₇ compounds, the formation of the compound is dominated by the enthalpy of formation of MCo₇, atomic radius ratio of Sm to (Co, M) and the electronic configuration of the doping element M, while the site occupation of M is determined by the enthalpies of solution of M in liquid Sm and Co as well as by the electronegativity difference among M, Sm and Co. However, the Sm(Co,Cu)₇ compounds exhibit different stabilizing mechanism, which may be due to the large mutual solubility between Co and Cu in the Sm(Co,Cu)₇. The stabilizing element Si and Cu prefer to occupy the 3g site, whereas Ti, Zr and Hf have preference to occupy the 2e site. Both the saturation magnetization and Curie temperature of the Sm(Co,M)₇ compounds decrease with increasing M content, while the magnetic anisotropy increases with increasing M content. The magnetic anisotropy field is related closely to the content and site occupation of the doping element M, which agrees with the theoretical analysis based on the individual site contribution model.     

Spin-valve magnetoresistance in Co/Si/（Co/Cu/Co） multilayers

A series of Co/Si/（Co/Cu/Co） multilayers and Co/Si/Co sandwiches were prepared by high vacuum electron-beam evaporation. It was found that a Si spacer （≥0.9 nm） could greatly decrease the interlayer coupling in Co/Si/Co sandwiches and there was no magnetoresistance（MR） or spin-valve MR in them due to the high resistivity of Si spacer. While in Co/Si/（Co/Cu/Co） multilayers, we observed a spin-valve MR of about 0.5% through a nominal 2.7 nm Si spacer at room temperature. The spin-valve MR in Co/Si/（Co/Cu/Co） multilayers was attributed to the enhanced spin polarization of conduction electrons caused by the top Co/Cu/Co sandwich with GMR mechanism and high spin-dependent scattering at Co/Cu interface.     

Co基纳米晶软磁合金研究进展

本文对钴基非晶合金的晶化及其磁性研究的进展进行了综述,内容包括：（1）零磁致伸缩Co基非晶合金的晶化行为;（2）Vitrovac 6025型合金的纳米晶化和磁性;（3）bcc结构的Co-Fe-Nb-Si-B纳米晶合金的研究。对有关晶化产物及磁性的问题进行了讨论。     

[Co／Ti],[Co／Cu（Ni）]多层膜的结构与磁性

用双对向靶溅射方法制备了具有非晶磁性的「Ｃｏ／Ｔｉ」３０，「Ｃｏ／Ｃｕ（Ｎｉ）３０」两组多层膜，分别用Ｘ射线衍射，透射电镜和振动样品磁强计做了结构和磁性测量，在以非晶Ｃｏ和Ｃｉｕ－Ｎｉ合金构成的「Ｃｏ／Ｃｕ（Ｎｉ）」多层膜中，发现饱和磁化强度Ｍｓ随非磁性层厚度ｄｓ的增国发生振荡变化；在以非晶Ｃｏ和Ｔｉ构成的「Ｃｏ／Ｔｉ」多层膜中，ＭＳ和则随ｄｓ的增加而减小。     

纳米晶SmCo_(8.9)Si_(0.9)永磁合金相变特征及其磁性能变化研究

首次制备出具有高稳定性的Sm Co_(8.9)Si_(0.9)纳米晶合金,进而系统研究了亚稳相Sm Co_(8.9)Si_(0.9)的相变特征及相应的磁性能变化规律。发现添加元素Si可以有效提高过饱和固溶体亚稳相SmCo_(9.8)的稳定性,随着热处理温度的升高,SmCo_(8.9)Si_(0.9)纳米晶合金由SmCo_(9.8)(H)结构的单相转变为Sm_2Co_(17)(H)和Co(fcc)相,且伴随相变,矫顽力提高。其机理源于析出的细小Co相造成钉扎机制增强。进一步升高热处理温度,Sm_2Co_(17)(H)相转变为Sm_2Co_(17)(R)相,同时晶粒长大明显且晶粒尺寸分布不均匀,导致磁性能下降。     

Effects of oxygen and carbon on the magnetic properties and microstructure of Sm2Co17 permanent magnets

The research on the sintered Sm2Co17 permanent magnets prepared by metal injection molding is still at the exploratory stage. Carbon and oxygen are two key factors that influence the magnetic properties. In this article, the effects of oxygen and carbon on the properties and microstructure of the magnets have been studied. The results indicate that oxygen consumes the effective Sm content of the magnets and forms Sm2O3-the non-magnetism phase, which result in the deterioration of the magnetic properties. Besides, the magnetic properties decrease in evidence with increasing carbon content. The main factor that affects the magnetic properties is the deterioration of the microstructure of the magnets. The Sm（Co, Cu）5 phase decreases, whereas the cell size increases with the increase of the carbon content. When the carbon content is above 0.43 wt.%, the Sm（Co, Cu）5 phase is not enough to form a uniform cellular microstructure. Thus the magnetic properties disappear. ZrC is detected in the magnets by XRD when the carbon content is above 0.21 wt.%. ZrC also reduces the properties of the magnets.     

纳米晶Fe72.8Cu1Nb1.7V1.5Mn0.5Si13.5B9软磁合金的磁性能

本文报道了高导磁纳米晶Fe72．8Cu1Nb1．7V1．5Mn0．5Si13．5B9合金的直流和交流磁性能水平，磁导率频散行为以及高频铁损行为，给出了描述高频区频散行为和铁损行为的近似表达式。     

CuCo2Be合金的热处理工艺及组织与性能研究

借助布氏硬度计、万能试验机、涡流导电仪、金相显微镜、扫描电镜、能谱仪和X射线衍射分析仪,研究了CuCo2Be合金不同热处理后的组织和性能、物相及组分。结果表明,CuCo2Be合金的最佳热处理工艺为950℃×1.5 h固溶+460℃×1.5 h时效,硬度和导电率达到较好的匹配。布氏硬度为254 HBS、导电率为47.24%IACS、抗拉强度为880.56 MPa;未固溶相主要为Co0.52Cu0.48、Cu6.69Si和Be2Cu,时效析出相可能为BeCo、Be2Cu和Co0.52Cu0.48。