制备条件对非晶态Fe78B13Si9合金的热膨胀各向异性的影响

本文研究了不同条件下形成的非易态Fe_(78)B_(13)Si_9合金在长轴和短轴方向上的热膨胀。结果表明,在所有条件下均存在热膨胀的各向异性。热膨胀系数随着冷却速度的增加而增加,但其各向异性减小;随着熔体喷铸温度的提高两者均减小。在热循环的作用下,短轴方向的热膨胀系数及其各向异性均减小;而在长轴方向的热膨胀系数却增大。我们认为热膨胀各向异性来源于原子交互作用力的方向性、原子振动频率和短程有序结构或缺陷的方向性。     

EFFECT OF PREPARATION CONDITION ON THERMAL EXPANSION ANISOTROPY FOR AMORPHOUS Fe_(78)B_(13)Si_9 ALLOY

The thermal expansion along the longitudinal and transverse directions for amorphousFe_(78)B_(13)Si_9 alloy prepared under various preparing conditions were investigated.The thermalexpansion anisotropy appears in all specimens.The expansion along the longitudinal directionis less than that along the transverse direction.The cooling rate,the melt temperature beforejet casting and the cycling temperature affect the thermal expansion coefficients andanisotropy.The amisotropy of thermal expansion originates from the orientation of atomicinteraction force,the atomic oscillatory frequency and short range order structure or thedirectional arrangement of defects in the alloy.     

Al原子在非晶合金Fe78Si9B13中的扩散

利用二次离子质谱(SIMS)并结合离子剥落研究了Al原子在非晶Fe_(78)Si_9B_(13)合金中的扩散。实验结果表明:在320-380℃温区内,扩散系数D位于2.43×10~(-22)-2.01×10~(-21)m~2s~(-1)之间,且它随温度的变化符合Arrhenius关系,D=D_0 exp(-Q/kT),其中指数前因子D_0=2.02×10~(-12)m~2s~(-1)。扩散激活能Q=1.17eV。     

Fe78B13Si9纳米晶合金的热性能研究

采用适当的热处理工艺将相同成分的Fe_(78)B_(13)Si_9非晶态合金条带晶化制备成纳米晶合金;测定并研究了纳米晶合金的微观结构(晶体结构及尺寸)和一些结构敏感性能(热膨胀、比热),同时,将其与同样成分的非晶态、大晶粒状态合金的性能进行比较分析,认为由于纳米晶合金特殊的微观结构(短程无序),使其在性能上表现出与通常材料有很大差异。     

THERMAL PROPERTIES OF NANOCRYSTALLINE Fe_78B_13Si_9 ALLOY

A new method was developed for preparing nanocrystalline alloy made of the identi-cal compositional Fe_(78)B_(13)Si_9 amorphous ribbon by suitable isothermal annealing.Itsmicrostructure and some structure-sensitive properties.including thermal expansion,spe-cific heat,etc.,have been studied and measured.Comparative analysis of properties wasalso carried out with amorphous and coarse-grained crystalline alloys of same composi-tion,thus.it is believed that so novel differences in properties from usual materials wouldbe made by the particular microstructure of short range disorder of the nanocrystallinealloy.     

ATOMIC SCALE MECHANISM OF RESTRAINED EMBRITTLEMENT IN AMORPHOUS Fe_(78)B_(13)Si_9 ALLOY BY ELECTRIC PULSE RAPID ANNEALING

1.IntroductionTheiron-basedamorphousalloysproducedviarapidquenchingtechniquepossessgoodmechanicalproperties.However,toacquiredesirablesoftmagneticproperties,alongperiodofconventionalfurnaceannealing(CFA)(1-2h)isrequired.Unfortunately,theannealingembrittlementoccursinevitablytocreatemanydifficultiesinpractice.Flashannealingorelectricpulserapidannealing(EPRA)isbasedonthejouleheatingeffectsofatransientcurrentpulseflowinginanamorphousribbon.RecentlyithasbeenprovedthatEPRAisasuitablemethodfori…     

溅射Fe82Si6B12非晶合金膜的晶化动力学研究

用动态原位电镜观察方法了直流溅射Ｆｅ８２Ｓｉ６Ｂ１２非晶合金膜的晶化动力学过程，结果表明：溅射Ｆｅ８２ＳｉＢ１２非晶合金膜的晶化类型为初晶晶化。初晶产物为α（Ｆｅ，Ｓｉ），长大以枝晶方式进行，长大方向沿＜１１０＞晶向。α（Ｆｅ，Ｓｉ）初晶形核采取瞬态均匀形枝，晶核初始的形状为圆形的多角形。并很快发展成枝晶，α（Ｆｅ，Ｓｉ）枝晶的长大是由Ｂ原子在非晶合金中的长程扩散控制的。根据长大过程的动力学分析，     

非晶（Fe0.99Cu0.01）78Si9B13合金等温晶化动力学

利用DSC,结合XRD,TEM实验,研究了(Fe_(0.99)Cu_(0.01))_(78)Si_9B_(13)非晶合金等温晶化动力学,结果表明:该合金等温晶化按两个阶段进行,分別析出α-Fe(Si)固溶体和Fe_2B化合物利用局域Avrami指数的概念分析了两相的形核长大方式。并作出了出合金晶化的“C”曲线,通过对两相晶化激活能的分析得出:α-Fe(Si)相较Fe_2B相容易晶化析出,同时,Cu元素的添加有助于改善α-Fe(Si)相的形貌。     

纵向磁场动态电脉冲快速退火FeBSi非晶合金的力性与磁性

采用动态电脉冲纵向磁场退火法，对Fe78B13Si9非品合金条带实施连续快速退火．测定了该合金条带的应力松弛、退火脆化及软磁性能随动态脉冲加热工艺参数的变化规律．试验结果表明，适当的动态脉冲加热工艺参数的配合，可以使Fe78B13Si9非晶合金条带的液淬内应力基本上完全松弛，磁性能优于最佳常规退火处理的条带性能，同时也完全消除了退火脆化现象．     

Fe76.5Cu1Si13.5B9非晶合金晶化过程的X射线衍射研究

Fe_(76.5)Cu_1Si_(13.5)B_9非晶合金在晶化过程中析山的α-Fe固溶体(α相)的X射线衍射峰存在不对称性并随退火温度而变化,对α相衍射峰进行分峰拟合证实,Cu原子可以促进α相形核并固溶其中,合金晶化与原始态中残存晶核无关,α相晶粒中Cu含量的不同导致衍射峰的不对称性,键合能准化学近似计算结果表明,Cu原子降低了周围原子的迁移势垒,导致合金的晶化首先在含Cu量较高的区域开始,使晶化温度降低。     

MAGNETIC PROPERTIES AND CRYSTALLIZATION BEHAVIOR OF AN AMORPHOUS（Fe＿（1－x）Mo＿x）＿（79）Si＿9B＿（13）ALLOY

ＭＡＧＮＥＴＩＣＰＲＯＰＥＲＴＩＥＳＡＮＤＣＲＹＳＴＡＬＬＩＺＡＴＩＯＮＢＥＨＡＶＩＯＲＯＦＡＮＡＭＯＲＰＨＯＵＳ（Ｆｅ＿（１－ｘ）Ｍｏ＿ｘ）＿（７９）Ｓｉ＿９Ｂ＿（１３）ＡＬＬＯＹＭＡＧＮＥＴＩＣＰＲＯＰＥＲＴＩＥＳＡＮＤＣＲＹＳＴＡＬＬＩＺＡＴＩ...     

非晶态Fe_（80）B_（20）合金的表观晶化动力学研究

研究了非晶Ｆｅ（８０）Ｂ（２０）合金的表观晶化动力学过程，分析表明，非晶态的Ｆｅ－Ｂ共晶合金在晶化过程中，晶体的生长行为与传统观点所认为的完全由界面控制的机制不同，还同时存在扩散控制机制．     

Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9非晶合金的晶化动力学

用差热分析(DTA)结合X射线衍射(XRD),研究了Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9非晶合金的晶化动力学。结果表明:温度在0～700℃范围内,该合金的晶化相为α-Fe和Fe_2B;α-Fe相晶化表观激活能为452.39kJ/mol,Fe_2B相的晶化表观激活能395.23kJ/mol;两相在晶化初期激活能最小,随晶化量X_c的增加而迅速增大,在α-Fe的体积分数为30％～80％,Fe_2B的体积分数为40％～80％时,呈现极大值。     

NANOCRYSTALLINE STRUCTURE AND INITIAL PERMEABILITY OF ANNEALED Fe_（73．5）Cu_1W_3Si_（13．5）B_9 Alloy

ＮＡＮＯＣＲＹＳＴＡＬＬＩＮＥＳＴＲＵＣＴＵＲＥＡＮＤＩＮＩＴＩＡＬＰＥＲＭＥＡＢＩＬＩＴＹＯＦＡＮＮＥＡＬＥＤＦｅ_（７３．５）Ｃｕ_１Ｗ_３Ｓｉ_（１３．５）Ｂ_９ＡｌｌｏｙＺＨＡＮＧＸｉａｎｇｙｉ,ＺＨＡＮＧＪｉｎｇｗｕａｎｄＺＨＥＮＧＹａｎｇｚｅ?..     

Co66Fe4Mo2Si16非晶合金的磁性与晶化

Ｃｏ６６Ｆｅ４Ｍｏ２Ｓｉ１６非晶合金在等温退火和等时退火过程中起始磁导率μｉ随退火时间的延长而增大，在ｔ＝４５ｍｉｎ时达到最大值。然后随着退火时间的延长μｉ快速下降，电子衍射图表明合金此时仍保持非晶结构；合金的饱和磁致伸缩系λｓ随退火时间的延长由负值逐渐变为正值，当ｔ＝４５ｍｉｎ时，λｓ≈０，合金在等温退火过程中起台磁导率的峰值主要来源于零磁致伸缩系数。     

（Fe_（0．99）Mo_（0．01））_（78）Si_9B_（13）非晶合金的低温韧脆性研究

用ＤＳＣ，ＳＥＭ，Ｃｕｒｉｅ温度和电阻测量等多种实验手段研究了非晶条带（Ｆｅ_（０．９９）Ｍｏ_（０．０１））_（７８）Ｓｉ_９Ｂ_（１３）的低温退火脆性．发现其特征脆化温度约为２４４℃，产生了一个有序度增加的结构弛豫过程．同时，伴随有纳米颗位α－Ｆｅ（Ｓｉ，Ｍｏ）多晶组织从非晶基体中析出．进一步提高退火温度，则由于新的有序原子团的出现，自由体积等可动单元再次增大，从而释放应力，恢复韧性．     

激波诱导非晶合金Fe78B13Si9的晶化

用ＸＲＤ和ＤＴＡ研究了波对Ｆｅ７８Ｂ１３Ｓｉ９非晶合金的影响。结果表明，一定强度的激波能使非晶态转变为晶态，且其晶粒尺寸在纳米范围内。     

Fe_(70)Cr_(18)Mo_2Si_1B_9单辊激冷带中的特殊结晶现象

本文研究了真空下不同转速的Fe_(70)Cr_(18)Mo_2Si_1B_9单辊激冷带的显微组织,并与大气带作了比较。除了常见的均质形核与非均质形核的结晶过程之外,还出现具有强择优取向的自由面表层α-Fe柱状晶以及尺寸达μm级的α-Fe球状晶。可用动量传递模式的单辊带形成理论解释这些现象。早期过冷液态中的预存核是该材料能否形成非晶的控制因素。     

UNUSUAL SOLIDIFICATION MICROSTRUCTURE OF Fe_(70)Cr_(18)Mo_2Si_1B_9 SINGLE-ROLL QUENCHED RIBBON

The solidification microstructure of Fe_(70)Cr_(18)Mo_2Si_1B_9 single-roll quenched ribbons with dif-ferent rotating speed of roller and under different atmosphere conditions was investigated.Apart from usual crystallization by homogeneous and heterogeneous nucleation,it was foundthat α-iron cohnnnar grains with strong preferred orientation formed beneath free surface andthat spheres of α-iron single coastal with a size of several μm up to 20μm,which have rarelybeen reported,appeared inside the ribbons.There was experirnental evidence suggesting thatclusters of metal atoms formed from fluctuation in early undercooled liquid might play a roleas pre-existed nuclei and,in fact,control the formation of amorphous for this alloy.     

BRITTLE-DUCTILE TRANSITION OF ANNEALEMBRITTLED Fe_(75)Si_(10)B_(15)METALLIC GLASS

Studies were made of the effect of mechanical pulverization on relaxation,crystallizationand brittle-ductile transition of the anneal-embrittled Fe_(75)Si_(10)B_(15) metallic glass rib-bon.Results show that the Curie temperature,T_C,decreases and the total enthalpy ofrelaxation increases gradually with variation of pulverized time.DSC traces reveal anextra exothermic peak,T_X_1,and a distinct glass transition endothermic peak,T_g_1,withincreasing pulverized time,T_C,T_X_1,and T_g_1 decrease simultaneously,and the exother-mic peak area corresponding to T_X_1 increases gradually.The surface slip-steps of flakyparticles and their corresponding shear are produced by pulverizing the pre-embrittledamorphous glass.The lost ductility of the glass may restore during annealing.