退火变脆Fe75Si10B15金属玻璃的脆韧性转变

研究了机械研磨对退火变脆Fe_(75)Si_(10)B_(15)金属玻璃的弛豫过程,晶化行为及脆韧性转变的影响。发现退火变脆的Fe_(75)Si_(10)B_(15)金属玻璃,经不同时间机械研磨,Curie温度T_C逐渐回落,总的弛像焓ΔH_?逐渐回升。在DSC曲线上观察到明显的玻璃转变温度T_(g_1)和一个附加的宽放热峰T_(x_1),随着研磨时间的增加,T_(x_1),T_(x_1),T_C同步降低,与T_(x_1)对应的放热面积ΔH_(x_1)逐渐增大,并在片状粒子表面形成切变带以及与其对应的剪切带,玻璃在退火过程中失掉的韧性逐渐得到恢复。     

INFLUENCE OF PURIFICATION ON GLASS FORMABILITY AND THERMOSTABILITY OF METALLIC GLASS Ni_(75)B_(17)Si_8

The glass formability of Ni_(75)B_(17)Si_8 melt and the thermostability of this metallic glass formedfrom the the melt can be enhanced by eliminating the heterogeneous catalystg. The purificationwas done by cyclical superheating melt in special glasses and subsequently cyclicallysuperheating it in an electromagnetic levitation apparatus. The purified Ni_(75)B_(17)Si_8 amorphoussample sized up to 20 ~ I0 x 0.5 mm was prepared as four times the thickness of unpurifiedones.     

净化对非晶形成能力和非晶热稳定性的影响SCIEI

采用玻璃熔体净化法和电磁悬浮循环过热法消除Ni_(75),B_(17)Si_R合金液内的异质核心,研究了净化对该合金液非晶形成能力和所形成的非晶合金热稳定性的影响。采用净化和忽冷相结合的工艺制备出了20×10×0.5mm的Ni_(75)B_(17)Si_8非晶试样,试样的厚度较净化前提高了4倍。     

DIFFUSIVITY OF Al IN AMORPHOUS ALLOY Fe_(78)Si_9B_(13)

Ion beam sputtering profiling in combination with SIMS technique was employed toinvestigate the Al diffusion in Fe_(78)Si_0B_(13)amorphous alloy.Between 320 and 380℃,thediffusion coefficients vary from 2.43×10~(-22) to 2.01×10~(-21)m~2s~(-1),and an Arrheniusrelationship was established as:D_0=2.02×10~_(12)exp(-1.17/kT)     

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。     

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，     

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.     

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.     

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.     

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。     

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…     

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

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预退火对Fe73.5Cu1Mo3Si13.5B9非晶合金的晶化及磁性的影响

本文研究了预退火温度和时间对Ｆｅ(７３．５)Ｃｕ１Ｍｏ３Ｓｉ(１３．５)Ｂ９非晶合金在最后退火过程中发生的 晶化及软磁性能的影响。结果表明：在较低温度下预退火能有效地控制合金的晶化过程,降低了最 后退火时所放出的晶化潜热。该合金在４５０℃进行１ｈ预退火发生部分晶化,释放约３２％的晶化 潜热,再经５１０℃保温１ｈ最后退火其磁性能与制备态样品经５１０℃退火后的磁性能相比,最大磁 导率ｍ显著提高,矫顽力Ｈｃ明显下降,Ｂｓ和Ｂｒ无明显变化。     

等温退火过程中Co66Fe4Mo2Si16B12非晶合金磁性及结构的变化

将Co66Fe4Mo2Si16B12非品合金在460℃等温退火30～120min。合金在460℃等温退火过程中，相对起始磁导率μi随退火时间的延长先增大，在t≈45min时达到最大值，然后随着退火时间的延长快速下降。电子衍射花样的结果表明，合金此时仍保持非品态结构．同时发现，合金的饱和磁致伸缩系数λs随退火时间的延长由负值逐渐变为正值，当t＝45min时，λs≈0，由此可知，合金在等温退火过程中相对起始磁导率的峰值与零磁致伸缩系数相对应。     

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．     

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．     

HEAT CAPACITIES OF Fe_（40）Ni_（40）B_（20） GLASSY ALLOY MEASURED BY ENTHALPY METHOD

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