退火条件对FeCuNbSiB非晶带材应力阻抗效应的影响

研究了退火条件对非晶FeCuNbSiB带材应力阻抗性能的影响.结果表明,当退火温度为300℃时,FeCuNbSiB非晶带材开始慢慢晶化,当温度上升到500℃时,带材内部结构已由非晶态完全转变成晶态.当退火温度低于300℃时,退火能够消除部分应力,使阻抗变化的灵敏度提高;但当退火温度高于300℃时,随着退火温度的升高,应力阻抗效应减弱.退火时间超过1 h,延长退火时间,对带材的应力阻抗性能影响不大.非晶FeCuNbSiB带材经100℃×2 h的退火处理后,应力为2.7 MPa时,应力阻抗变化可达26%.     

退火工艺对FeSiB非晶带材脆性的影响

研究了热处理工艺对FeSiB非晶带材韧性的影响情况，结果表明．当退火温度为300℃时，FeSiB非晶带材开始慢慢晶化，当温度上升到500℃时，带材内部结构已由非晶态完全转变成晶态。退火温度对非晶带材的脆化起决定作用，退火温度越高，带材脆化程度越大，250℃是带材脆化的临界温度。当保温时间低于临界脆化时间时，带材脆化程度随时间逐渐上升。保温时间达到临界脆化时间时，带材脆化程度趋于稳定。     

退火条件对FeCuNbSiB非晶带材应力阻抗效应的影响

研究了退火条件对非晶FeCuNbSiB带材应力阻抗性能的影响。结果表明,当退火温度为300℃时,FeCuNbSiB非晶带材开始慢慢晶化,当温度上升到500℃时,带材内部结构已由非晶态完全转变成晶态。当退火温度低于300℃时,退火能够消除部分应力,使阻抗变化的灵敏度提高;但当退火温度高于300℃时,随着退火温度的升高,应力阻抗效应减弱。退火时间超过1h,延长退火时间,对带材的应力阻抗性能影响不大。非晶FeCuNbSiB带材经100℃×2h的退火处理后,应力为2.7MPa时,应力阻抗变化可达26%。     

退火工艺对Fe_(91.63)B_(1.27)Si_(7.09)非晶带材腐蚀性能的影响

采用真空电弧炉铜模铸造法制备出Fe_(91.63)B_(1.27)Si_(7.09)非晶带材,并用失重法对比研究了非晶带材在HCl、H_2SO_4溶液里的腐蚀行为;采用X射线衍射仪和光学显微镜对该非晶带材的相组成、晶化过程及试样的腐蚀形貌进行了研究,并综合分析了退火工艺对Fe_(91.63)B_(1.27)Si_(7.09)非晶带材耐腐蚀性能的影响。结果表明:Fe_(91.63)B_(1.27)Si_(7.09)非晶带材在20%H2SO_4溶液中的耐蚀性比45钢高300倍。非晶合金晶化程度随退火温度升高而提高,带材的腐蚀速率取决于退火温度。在500℃以下退火时,Fe_(91.63)B_(1.27)Si_(7.09)非晶带材腐蚀速率变化不大;在500℃以上退火时,Fe_3Si相和Si_4Cu_(15)相析出,腐蚀速率明显增大;当退火温度上升到700℃时,已由非晶态完全转变成晶态,腐蚀速率大幅度提高。     

微稀土化非晶带材的晶化行为和磁阻抗效应

将稀土La元素掺杂Fe73.5Cu1Nb3Si13.5B9合金,采用单辊法制备了FeCuNbSiB-La合金带材。用XRD分析了带材的晶化行为,用阻抗分析仪测试了带材的磁阻抗效应。结果表明,淬火态FeCuNbSiB-La合金带材为非晶态结构,经550℃晶化热处理后的FeCuNbSiB-La(0.5wt%)非晶带材形成了非晶和纳米晶双相共存结构;FeCuNbSiB-La非晶带材的磁阻抗效应随测试频率的升高和磁场强度的增大而增大,随稀土La元素含量的增大呈先增大后减小的趋势。     

微晶合金5БДCP带材在环形变压器磁路中的应用

微晶合金５БДＣＰ带材在环形变压器磁路中的应用非晶合金包括组织均匀的非晶态合金和具有非晶－结晶态混合的组织不均匀合金，后者也叫做微晶合金，微晶合金的电磁性能远远优越于非晶态合金。微晶合金的综合性能，在很大范围变化的外界环境（如温度和湿度等）影响下都很...     

稀土改性非晶带材的制备与软磁性能研究

利用稀土La掺杂Fe73.5Cu1Nb3Si13.5B9非晶合金,成功制备了稀土La改性的非晶带材.对制得的非晶带材进行热处理和显微组织分析,最后测试了带材的软磁性能.结果表明添加La改变了非晶带材的晶化温度,随着La含量的增加,晶化温度呈下降趋势.显微金相分析表明带材表面存在纹路,且纹路随着热处理温度的变化而变化.带材中内应力分布不均造成带材的厚度随温度变化而波动.La原子加入后使非晶带材的尺寸波动范围变窄,尺寸波动的临界温度也由400℃下降到300℃;在550℃×0.5 h热处理工艺时,FeCuNbSiB(La-0.5wt%)带材综合软磁性能最佳,饱和磁感强度可达到1.7 T以上,磁导率为5306.     

Sn元素对Mg-Zn-Ca合金非晶形成能力和耐蚀性的影响

采用熔体旋淬和铜模喷铸法制备了不同Sn含量的Mg-Zn-Ca-Sn合金带材和直径2 mm的棒材试样。运用XRD、SEM、DSC和电化学测试方法研究了Sn元素对Mg-Zn-Ca合金非晶形成能力和在模拟体液中腐蚀行为的影响。结果表明,带材组织均为非晶态,而棒材试样随着Sn含量的增加,由不含Sn元素的完全非晶态,逐渐转变为由Mg和Mg2Sn相组成的多晶态组织,说明Sn元素的添加恶化了Mg-Zn-Ca合金的非晶形成能力。电化学腐蚀测试结果表明随着Sn含量的增多,腐蚀电位负向移动,腐蚀电流密度增大,合金的耐蚀性逐渐下降。     

非晶FeCuNbSiB带材压磁性能的特点

采用点压方式研究非晶FeCuNbSiB带材的压磁性能,利用X-Ray测试带材结构,用DSC确定相转变,用4294A阻抗分析仪测试阻抗.结果表明:非晶FeCuNbSiB带材具有优越的压磁性能和压磁稳定性,压磁敏感性可以通过调整退火工艺来实现.当退火温度为300℃,保温时间为1 h时非晶FeCuNbSiB带材的压磁性能最佳,在压力为1.42 MPa,频率为100MHz时,|△Z|可达2.88Ω.     

新型非晶、纳米晶和微晶软磁合金的生产、应用和前景

新型非晶、纳米晶和微晶软磁合金的生产、应用和前景１９９６年９月在俄国召开了第六次“非晶态精密合金：制取工艺、性能和应用”国际会议，会议提出了集中专家力量重点解决的几项任务：（１）制定出能保证稳定地生产符合规定化学成分和厚度的非晶带材，以及非晶薄带（＜...     

Structural evolution during crystallization in phase separated Ti–Y–Al–Co metallic glass

Structural evolution during heat treatment of melt spun Ti₃₆Y₂₀Al₂₄Co₂₀ alloy was studied using differential scanning calorimetry, X-ray diffractometry and transmission electron microscopy. The as-melt spun Ti₃₆Y₂₀Al₂₄Co₂₀ specimen showed a hierarchical complex microstructure consisting of Ti-rich and Y-rich amorphous phases and crystallized with two-step process. Crystallization in the phase separated two phase mixture took place in a confined mode due to different thermal stability and complex microstructure, resulting in various nano-scaled microstructural formation ranging from fine distribution of crystalline particles in amorphous matrix to fine distribution of amorphous particles in crystalline matrix.     

NEW AMORPHOUS Al-La-Y-Ni(Fe)QUATERNARY ALLOYS WITH SUPERIOR STRENGTH AND DUCTILITY

The melt spun ribbons of Al-La-Y-Ni(Fe)quaternary alloys were prepared by a single-roller melt spinning technique in vacuum.Their amorphous nature,mechanical propertiesand tensile fracture surface morphology were investigated.The experimental results showthat amorphous alloys with high strength and good ductility as well as good thermalstability can be achieved in Al-La-Y-Ni(Fe)system,when the alloy contains 85—90at.-% Al and less than 10 at.-% La+Y.The maximum tensile fracture strength(σ_f)and microhardness(HV)are as high as 760 MPa and 294 DPN,respectively.The as-quenched ribbons can be bent 180 degree without fracturing.The dominant factors forformation of amorphous Al-La-Y-Ni(Fe)are the strong attractive interaction among Al,La,Y and a decrease of melting temperature.     

Investigation of Electrochemical Hydrogen Storage Kinetics of Melt Spun Nanocrystalline and Amorphous Mg2Ni-type Alloy

用快淬工艺制备了Mg2Ni型合金,其名义成分为Mg2Ni1-xCox(x=0,0.1,0.2,0.3,0.4)。以XRD、SEM、TEM分析了铸态及快淬合金的结构。用程控模拟电池测试仪测试了合金的电化学贮氢动力学。用电位跃迁法计算了氢在合金中的扩散系数。用电化学工作站测试了合金的电化学交流阻抗谱(EIS)和Tafel极化曲线。结果表明,快淬态无Co合金具有典型的纳米晶结构,而Co含量为0.4的快淬态合金具有纳米晶/非晶结构,表明Co替代Ni可以提高Mg2Ni型合金的非晶形成能力,且快淬态合金的非晶化程度随Co替代量的增加而增加。Co替代Ni显著地提高了合金电化学贮氢动力学。当Co含量从0增加到0.4时,淬速为25m/s的快淬态合金的高倍率放电能力(HRD)从65.3%增加到75.3%,氢扩撒系数(D)从2.22cm2/s增加到3.34cm2/s,极限电流密度(IL)从247.8mA/g增加到712.4mA/g。     

Effect of La on the crystallization behaviour of amorphous Al94 − xNi6Lax (x = 4–7) alloys

Melt spun and annealed Al-alloys containing 6 at.% Ni and 4–7 at.% La were investigated by means of differential scanning calorimetry (DSC), X-ray diffractometry (XRD), small angle neutron scattering (SANS), transmission electron microscopy and hardness measurements. XRD studies revealed that all the ribbons were fully amorphous, whereas SANS indicated concentration fluctuations. DSC showed that the amorphous alloys undergo a two-stage crystallization process upon heating. The details of the crystallization pathway depend on the La concentration. Upon annealing, SANS measurements revealed two different distributions of particles which can be explained by a core shell structure or two different types of particles. Moreover, significant changes in hardness occur which are attributed to changes in microstructure.     

Improvement of glass forming ability and soft magnetic properties of Fe-C-Si-P amorphous alloys through a flux treatment technique

Effects of fluxing treatment on the glass forming ability and magnetic properties of Fe-based amorphous alloys prepared using industrial raw materials have been studied. The partially amorphous Fe₇₆Si₈P₉C₇ rod with the diameter of 1 mm was prepared by suction casting technique from the fluxed master alloy based on the industrial raw materials, while the alloy rod with the diameter of 1 mm obtained from the un-fluxed master alloy does not involve any amorphous phase. Melt spun ribbons prepared using the fluxed master exhibited lower the coercivity H _c and power loss than those for ribbons prepared using the un-fluxed master alloy. These beneficial effects should be attributed to the purification of the master alloy through flux treatments. The results reveal that fluxing technique can play an important role in the development of Fe-based bulk metallic glasses using industrial raw materials with relatively low purities.     

Analyzing the Effects of Milling and Sintering Parameters on Crystalline Phase Evolution and Mechanical Properties of Al86Ni8Y6 and Al86Ni6Y4.5Co2La1.5 Amorphous Ribbons

In the present study, Al₈₆Ni₈Y₆ and Al₈₆Ni₆Y_4.5Co₂La_1.5 bulk amorphous nanocomposites were synthesized by spark plasma sintering of milled melt spun ribbon particles. The as-cast ribbons were of near amorphous nature with minute amount of FCC Al embedded in the amorphous matrix. Milling of the ribbons resulted in partial devitrification due to mechanical crystallization. The milled ribbon particles were sintered in the temperature and pressure range of 300-500 °C and 500-700 MPa, respectively. It was observed that nominal amount of amorphous phase was retained at 500 °C and 500 MPa. With increase in sintering pressure and decrease in sintering temperature, the amount of crystalline phase evolution decreased, and maximum amount of amorphous phase was retained at 300 °C and 700 MPa. The microstructure consisting of amorphous phase embedded with hard intermetallic phases led to increase in the nanohardness of Al₈₆Ni₈Y₆ and Al₈₆Ni₆Y_4.5Co₂La_1.5 as-cast ribbons from 3.26 ± 0.59 GPa and 3.81 ± 0.58 GPa to 6.06 ± 0.70 GPa and 6.14 ± 0.82 GPa, respectively, for the corresponding consolidated amorphous nanocomposite. Microhardness of the three and five component system bulk samples was 4.19 ± 0.13 GPa and 3.6 ± 0.13 GPa, respectively.     

Al91Ni7Y2纳米非晶复合材料晶化的研究

利用差示扫描量热(DSC)、透射电镜(TEM)和X射线衍射(XRD)技术,对快速凝固Al91Ni7Y2,合金条带急冷态和不同温度退火态的晶化行为及显微结构演化进行了研究。结果表明：急冷态的Al91Ni7Y2合金为部分Al粒子均匀分布在非晶基底上的复合材料。从急冷态到高温平衡态有三阶段晶化过程,对所有的晶化温度和晶化相的测量表明,DSC曲线上第一个峰的初始和峰值温度分别为240℃和267℃(在加热速率为10℃／min条件下),这一相对高的温度表明此复合材料有高的热稳定性。     

弯曲应变下Co66Fe4Cr2Si12B16非晶态合金带应力阻抗效应

对具有负磁致伸缩系数的Co66Fe4Cr2Si12B16非晶合金带在制备态下及经脉冲电流退火下的应力阻抗效应进行了研究.结果表明:长为50 mm的非晶带,在仅5 mm挠度的弯曲应变作用下材料可显示显著的应力阻抗效应,输出电压幅值变化率大于40%.非晶材料经电流密度为35 A/mm2,频率为2 Hz,持续时间为30 s的脉冲电流退火处理后,可改善应力阻抗效应灵敏度.该非晶材料受张应力作用时阻抗减小,受压应力作用时阻抗增大,弯曲应变下的应力阻抗效应可用于制作具有高应变因子的力传感器及新型智能材料.     

块体非晶合金制备技术展望

非晶合金的初始状态多为粉末或薄条带,这就大大限制了非晶合金的许多优异性能的发挥以及在工业中的应用。所以开发研究块体非晶合金有其重大的理论和应用价值。本文从四个研究方面归纳了当前研究状况,即粉末冶金技术、固态反应、从液相中直接制取、非晶条带直接复合等。本文简单介绍了前三种方向,重点论述非晶条带直接复合即非晶块的爆炸焊接制备技术,复合后的块体能保证非晶态,用它来制备非晶合金块的前景广阔。     

Magnetic properties of Nd_2Fe_(14)B/α-Fe nanocomposite magnets with yttrium addition

The phase evolution and magnetic properties of Nd9?xYxFe72Ti2Zr2B15 (x = 0,0.5,1,and 2) melt-spun nanocomposite ribbons were studied.It is found that Y addition not only enhances the formability of amorphous phase in the alloy,but also stabilizes the amorphous phase during the annealing treatment.The appropriate content of Y addition effectively enhances the remanence (Jr) of the annealed sample.The residual amorphous intergranular phase in the annealed sample optimizes the squareness of the loop,resulting in an larger maximum energy product (BH)max.The best magnetic properties,Jr = 0.78 T,Hci (coercivity) = 923.4 kA/m,and (BH)max = 98.5 kJ/m3,were obtained from the Nd8YFe72Ti2Zr2B15 ribbon spun at Vs = 4 m/s and annealed at 700°C for 10 min,which is composed of Nd2Fe14B,α-Fe,and amorphous phase.