Nanocrystallization of Amorphous Fe73. 5 Cu1 Nb3 Si13. 5 B9 Irradiated by Laser

The surface nanocrystallization of amorphous Fe73.5 Cu1Nb3Si13.5B9 radiated by CO2 laser was studied by means of M（oe）ssbauer spectroscopy, transmission electro iroscope and X-ray diffraction. The result shows that under certain technical conditions, nanocrystalline is fiound on the surface of amorphous Fe73.5 Cu1Nb3Si13.5B9 radiated by laser; the crystallization phase is α-Fe（Si） crystalline, and its size is about 10-20 nm; the nanocrystalline is uniformly distributed on amorphous base to keep the amorphous and crystallized phase in balance; the a mount of crystallization reaches 23% when the laser power is 300 W, the diameter of light spot is 20 mm, and the radiation speed is 20 mm/s. The phase balance can be controlled by adjusting the laser technology parameter. Laser radiation on the amorphous Fe73.5 Cu1Nb3Si13.5B9 alloy is an important technique for surface nanocrystallization of the amorphous alloys.     

Co68.5Fe4Si10B17.5非晶合金晶化动力学行为研究

采用示差热分析(DSC)研究了旋铸急冷法在大气环境中制备出的Co68.5Fe4Si10B17.5非晶合金的非等温晶化的动力学行为。研究发现:在连续加热条件下,随升温速率的加快,合金的特征温度Tg,Tx,Tp均向高温区移动。当分别采用晶化开始温度和峰值温度时,所得非晶合金的激活能并不是稳定值。用Doyle-Ozawa方法计算出的激活能值比Kissinger法计算出的激活能值要大。非晶态Co68.5Fe4Si10B17.5合金的晶化百分比与退火温度和退火时间的关系曲线均呈S型。随加热速度的增加,非晶合金的晶化百分比与温度的关系曲线向高温处移动。     

差示扫描量热法测试非晶合金居里温度

从坩埚选择、试样称取量、升温速率等方面摸索了差示扫描量热法(DSC)测试非晶材料 Fe78 Si9 B13居里温度的最佳试验条件,分析了不同升温速率对测试结果的影响,同时与该材料晶化温度、In(标准物质)的熔点随升温速率的变化情况进行了对比分析.研究结果表明：该材料的 DSC 曲线上居里转变过程对应的热信号表现为一个抖动.不同条件下测得的居里温度为399~402℃,与 Hall 效应法测试结果基本一致.最佳的试验条件是：Al坩埚、试样称取量6 mg 左右、20 K/min.在升温速率不小于10 K/min 时可以得到居里转变信号,与该材料晶化温度受热滞后影响而明显随升温速率增大而增大的情况不同,由于居里转变过程相变潜热较小,居里温度测试结果基本不受热滞后的影响.     

Glass Forming Ability and Magnetic Property of Fe74Al4Sn2 （PSiB）20 Amorphous Alloy

Amorphous ribbons of Fe74 Al4Sn2 (PSiB)20 alloy have been synthesized by melt spinning and axial design method. The thermal properties of the amorphous ribbons have been measured by differential scanning calorimeter (DSC). The DSC results show that the Fe74 Al4Sn2P12Si4B4 amorphous alloy has relatively wider supercooled liquid region with a temperature interval of 40.38 K (△TX=TX-TR). The alloys with a higher phosphorous content in the metalloid element composition triangle of Fe74Al4Sn2(PSiB)20 have high glass forming ability. The amorphous alloys also show good magnetic properties in which Fe74Al4Sn2P6.67Si6.67B6.67 alloy has a large maximum permeability (μm), Fe78AlSn2P3Si3B10 alloy exhibits a high squareratio (Br/Blo) and FeT~A14Sn2P, Sil2B4 shows a low core loss (P0.5 1.3T). High glass forming ability and good magnetic properties make Fe74Al4Sn2(PSiB)20 amorphous alloys valuable in future research.     

Heat flow model of glass formation and crystallization on rapid quenching

The theoretical model of glass formation and partial crystallization during rapid solidification of a metallic melt describes the homogeneous nucleation within the undercooled melt as well as the heat transfer into the metallic chill substrate. The calculated maximum thicknesses of amorphous foils at quenching onto a copper substrate increase in the order of alloys FeC, FeB, NiSiB and PdSi. Reducing the foil-substrate heat transfer coefficient, increasing the casting temperature and utilizing a steel substrate cause the attainable amorphous foil thickness to decrease. In foils with a large volume fraction crystallized the cooling process is not monotonous. The minimum density of quenched-in nuclei is situated at the substrate-side surface in amorphous foils and at the surface away from the substrate in crystalline foils.     

成分对非晶态Fe—B—Si合金退火脆化行为的影响

本文研究了Ｂ和Ｓｉ的含量及Ｆｅ／（Ｂ＋Ｓｉ）相对含量对非晶态Ｆｅ－Ｂ－Ｓｉ合金退火脆化行为的影响；分析了在常规热处理条件下，利用成分的变化，获得延性与磁性综合性能的可能性。实验结果表明，非晶态Ｆｅ－Ｂ－Ｓｉ合金的退火脆化行为具有较大的成分依赖性，位于Ｆｅ７９ａｔ％－８１ａｔ％，Ｂ１１ａｔ％，Ｓｉ８ａｔ％－９ａｔ％成分范围内的Ｆｅ－Ｂ－Ｓｉ非晶态合金的退火脆化敏感性最小，脆化仍发生于晶化开始之前...     

Fe-Si-B非晶带材高温氧化行为及回收工艺

??In order to reduce the oxidative burning loss of Fe78Si9B13 amorphous ribbon in the recovery process?? the oxidation behavior of Fe78Si9B13 amorphous ribbon was studied. The results show that the oxidation of Fe78Si9B13 amorphous ribbon at high temperature is related to the heating rate. The oxidation weight gain of Fe78Si9B13 amorphous ribbon at 5 and 10K/min from room temperature to 1223K are 44% and 31% respectively. There is an oxide layer with loose texture and a small amount of microcrack at the interface between the sample and atmosphere by SEM. The oxide layer contains a large amount of Fe2O3 and a little SiO2 by XRD. Oxidation kinetics curve shows that the oxidation weight gain of the samples follows a linear rule within 5hours at 1073 and 1173K?? then a parabolic rule. At 1273K?? however?? it only follows a linear rule?? meanwhile the oxidation speed is very fast?? with the oxidation weight gain reaches 40% in 12min. The oxidation weight gain in the amorphous ribbon recycling process can be reduced through cutting down the furnace gas temperature?? compressing the waste ribbon and unqualified products in the packaging process and blowing argon to reduce the partial pressure of oxygen in the furnace. Thus the slag decreases to 9-10g when 1kg waste ribbon is recovered?? and the Si content of liquid alloy increases to 8. 9%.     

Structural study of amorphous ZrFeB and ZrFeSi alloys by 57Fe-Mössbauer and magnetization measurements

The short-range order of melt-spun and mechanically alloyed ZrFeB and ZrFeSi amorphous alloys has been studied by means of ⁵⁷Fe-Mössbauer effect and magnetization measurements. It is shown, that the Fe-surrounding for the Fe concentrations up to 40at.% is nearly independent from additional B alloying, whereas significant changes are obtained for Si additions. It is indicated, that B mainly occupies interstial sites with pure Zr surroundings, whereas Si substitutes on Fe sites. The complete determination of the electric field gradient via magnetic distortion leads to the conclusion, that the same well-defined structural unit is present as observed for binary ZrFe glasses for Fe contents up to 33 at.%. Beyond this concentration, evidence is obtained that separation into a paramagnetic and a ferromagnetic amorphous phase takes place. The ferromagnetic component shows strong induced magnetization in high external fields far above the Curie temperature, preventing the complete determination of the electric field gradient tensor.     

Study on Annealing Embritlement of Fe-B-Si Amorphous Alloy

ＳｔｕｄｙｏｎＡｎｎｅａｌｉｎｇＥｍｂｒｉｔｌｅｍｅｎｔｏｆＦｅ┐Ｂ┐ＳｉＡｍｏｒｐｈｏｕｓＡｌｏｙＣａｏＸｉｎｇｇｕｏ①，ＧｕｏＺｅｃｈｅｎ①，ＣｈｅＸｉａｏｚｈｏｕ②，ＬｉｕＰｉｎｇ①，ＹｉｎＢｉａｏ①ＡＢＳＴＲＡＣＴＴｈｅｌａｗａｎｄａｃｔｉｖ...     

Diary

Abstract

The addition of amorphous Fe–Si–B particles to Fe powder increases the shrinkage of sintered components resulting in higher densification rates. Consequently, several research groups worldwide have studied the properties of such systems in an attempt to produce superior structural alloys. In the present work, Fe₇₅Si₁₀B₁₅ ribbons obtained by melt spinning were milled in a high energy Spex mill for times varying from 2 to 32 h. The resulting powders were characterised by differential thermal analysis and X-ray diffraction. The results showed that the amorphous characteristics of the ribbons persisted after the milling process. Next, samples consisting of a mixture of Fe powder and 4 wt-% milled amorphous phase were uniaxially pressed and sintered following a series of thermal cycles. High temperature microstructures were obtained for compacts subjected to rapid cooling from the sintering temperature. The results of scanning electron microscopy and energy dispersive spectroscopy revealed substantial precipitation of fine Fe₂B particles before α → γ allotropic transformation. In addition, an oxide phase was observed in the interface between Fe and the additive particles. Preliminary analysis suggested that the oxide particles can be easily reduced by adding small amounts of carbon to the system. PM/0765     

Formation of magnetic anisotropy in amorphous Fe–Ni–B–Si alloys

The influence of annealing at 520°C on the saturation magnetic field and coercive force of amorphous 2NSR Fe–Ni–B–Si alloys is investigated. As a result of annealing, the saturation magnetic field reaches 1000–1800 Oe. Regions of short-range order (clusters) with a direction in which the atomic pairs are ordered are thought to be formed in the alloys. The formation of the coercive force in amorphous 2NSR alloys is described.     

Problem and Improvement of Kissinger Method──New Method on Measuring Crystallization Activation Energy of Amorphous Alloy

ＰｒｏｂｌｅｍａｎｄＩｍｐｒｏｖｅｍｅｎｔｏｆＫｉｓｓｉｎｇｅｒＭｅｔｈｏｄ──ＮｅｗＭｅｔｈｏｄｏｎＭｅａｓｕｒｉｎｇＣｒｙｓｔａｌｌｉｚａｔｉｏｎＡｃｔｉｖａｔｉｏｎＥｎｅｒｇｙｏｆＡｍｏｒｐｈｏｕｓＡｌｌｏｙＣａｏＸｉｎｇｇｕｏ；ＣｈｅＸｉａｏ...     

大块锆基非晶合金电化学耐腐蚀行为的试验研究

利用电化学极化曲线方法研究了Zr41Ti14Cu12．5Ni5Be22．5Fe5非晶合金及成分相同的晶化合金及纯Zr在硫酸溶液中的腐蚀行为。利用减重法研究了Zr41Ti14Cu12．5Ni5Be22．5Fe5非晶合金及成份相同的晶化合金在浓硫酸溶液中的腐蚀行为。极化曲线测试结果表明，非晶合金及成分相同的晶化合金与纯金属Zr有很大差异：非晶合金过钝化电位最高，钝化区最长，而纯金属Zr过钝化电位最低；钝化区也最短。减重试验表明，非晶合金的腐蚀速率是成分相同晶化合金的1/4。以上结果表明非晶合金拥有优良的耐腐蚀性能。     

Localized Recrystallization in Cast Al-Si-Mg Alloy during Solution Heat Treatment: Dilatometric and Calorimetric Studies

During heat treatment, the work piece experiences a range of heating rates depending upon the sizes and types of furnace. When the Al-Si-Mg cast alloy is heated to the solutionizing temperature, recrystallization takes place during the ramp-up stage. The effect of heating rate on recrystallization in the A356 (Al-Si-Mg) alloy was studied using dilatometric and calorimetric methods. Recrystallization in as-cast Al-Si alloys is a localized event and is confined to the elasto-plastic zone surrounding the eutectic Si phase; there is no evidence of recrystallization in the center of the primary Al dendritic region. The size of the elasto-plastic zone is of the same order of magnitude as the Si particles, and recrystallized grains are observed in the elasto-plastic region near the Si particles. The coefficient of thermal expansion of Al is an order of magnitude greater than Si, and thermal stresses are generated due to the thermal mismatch between the Al phase and Si particles providing the driving force for recrystallization. In contrast, recrystallization in Al wrought alloy (7075) occurs uniformly throughout the matrix, stored energy due to cold work being the driving force for recrystallization in wrought alloys. The activation energy for recrystallization in as-cast A356 alloy is 127 KJ/mole. At a slow heating rate of 4.3 K/min, creep occurs during the heating stage of solution heat treatment. However, creep does not occur in samples heated at higher heating rates, namely, 520, 130, and 17.3 K/min.     

磁场退火对Fe80Si9B11非晶合金的磁致伸缩特性影响

摘要：利用激光多普勒法测量50Hz下非晶合金带材的磁致伸缩曲线,研究了磁场退火对Fe80Si9B11非晶合金带材的磁致伸缩特性的影响。结果显示,在相同的磁场强度下非晶带材经横磁退火后磁致伸缩最大,无磁场退火次之,纵磁退火时最小。然后,采用Kerr方法观察了非晶合金带材的磁畴形貌,从微观结构上解释了经不同磁场退火后磁致伸缩大小不同的机理。最后,对无磁场退火、横磁退火和纵磁退火后的Fe80Si9B11铁基非晶合金铁芯进行了噪音测试。结果显示,在相同的频率和磁通密度下,非晶合金铁芯经横磁退火后噪音最大,无磁场退火次之,纵磁退火时噪音最小,与非晶合金带材经不同磁场热处理后磁致伸缩大小的规律一致。为解决非晶合金铁芯在实际应用中的噪音问题提供了参考。     

热处理温度对铝钢复合板界面组织和性能的影响

摘要：利用激光多普勒法测量50Hz下非晶合金带材的磁致伸缩曲线,研究了磁场退火对Fe80Si9B11非晶合金带材的磁致伸缩特性的影响。结果显示,在相同的磁场强度下非晶带材经横磁退火后磁致伸缩最大,无磁场退火次之,纵磁退火时最小。然后,采用Kerr方法观察了非晶合金带材的磁畴形貌,从微观结构上解释了经不同磁场退火后磁致伸缩大小不同的机理。最后,对无磁场退火、横磁退火和纵磁退火后的Fe80Si9B11铁基非晶合金铁芯进行了噪音测试。结果显示,在相同的频率和磁通密度下,非晶合金铁芯经横磁退火后噪音最大,无磁场退火次之,纵磁退火时噪音最小,与非晶合金带材经不同磁场热处理后磁致伸缩大小的规律一致。为解决非晶合金铁芯在实际应用中的噪音问题提供了参考。     

Electrochemical Behavior of Bulk Amorphous Steel Fe55M2Cr12Mo10B6C13Y2（M=Ni, Cu, Nb）

 Fe55Ni2Cr12Mo10B6C13Y2,Fe55Cu2Cr12Mo10B6C13Y2 and Fe55Nb2Cr12Mo10B6C13Y2 alloys with diameter of 4mm were produced by copper mold casting. The role of alloying additions (Ni, Cu or Nb) on corrosion resistance of Fe55Nb2Cr12Mo10B6C13Y2, Fe55Ni2Cr12Mo10B6C13Y2 and Fe55Cu2Cr12Mo10B6C13Y2 alloys were studied by polarization curves and electrochemical impedance spectroscopy (EIS). The results show that Fe55Ni2Cr12Mo10B6C13Y2 and Fe55Cu2Cr12Mo10B6C13Y2 alloys can be cast into bulk metallic glasses. Fe55Ni2Cr12Mo10B6C13Y2 and     

Investigation on RQ Embrittlement Mechanism of FeCuNbSiB Soft Magnetic Alloy

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Electrochemical Behavior of Bulk Amorphous Steel Fe55M2Cr12Mo10B5C13Y2(M=Ni,Cu,Nb)

Fe55Ni2Cr12Mo10B6C13Y2,Fe55Cu2Cr12Mo10B6C13Y2 and Fe55Nb2Cr12Mo10B6C13Y2 alloys with diameter of 4 mm were produced by copper mold casting. The effect of alloying additions (Ni,Cu or Nb) on corrosion resistance of Fe55 Ni2 Cr2Mo10 B6 C13 Y2,Fe55Ni2Cr12Mo10B6C13Y2 and Fe55 Cu2 Cr12 Mo10 B6 C13 Y2 alloys was studied by polarization curves and electrochemical impedance spectroscopy (EIS). The results show that Fe55Ni2Cr12Mo10B6C13 Y2 and Fe55Cu2Cr12Mo10B6C13 Y2 alloys can be cast to form bulk metallic glasses. Fe55Ni2Cr12Mo10B6C13 Y2 and Fe55Cu2Cr12 Mo10B6C13Y2 amorphous alloys with passive potential about 1500 mV exhibit good corrosion resistance in NaCl solution of 5 % and 1 mol/L HC1 solution. The passive current density of the alloy with Ni addition is lower than that of other alloys. EIS results only show one impedance element. Amorphous alloy Fe55 Ni2 Cr12 Mo10 B6 C13 Y2 with larger charge transfer reaction resistance indicates good corrosion resistance.     

Preparation of Si- Mn- N alloy by adding nitrogen to silicon- manganese alloy

Under the laboratory conditions, nine kinds of temperature regimes were designed to prepare Si- Mn- N alloy and the effect of heating rate, holding temperature, holding time and cooling rate on the increased nitrogen content in Si- Mn alloy was investigated by differential thermal analyzer. The results show that increased nitrogen content in Si- Mn alloy sample is 5. 45 mass%-37. 92 mass%, and the average value is 19. 33 mass%. The main factors influencing increased nitrogen content in Si- Mn alloy are heating rate, holding temperature and holding time. The optimum heating rate, optimal temperature range, and holding time for increasing nitrogen in Si- Mn alloys are 5??/min, 1100-1400?? and 4h, respectively. Under the optimum temperature range of 1100-1400??. and holding for 4h, the Si- Mn alloy has the largest nitrogen content. At this time, nitrogen content in the silicon- manganese alloy is 32. 8 mass%. and the main phase is Si3N4, MnSiN2 and Fe2Si by XRD analyzer. The nitrogen- enhancement process of Si- Mn alloy is a process in which solid- state and liquid- state Si- Mn alloys react with nitrogen. The nitrogen- enhancement rate of the liquid- state Si- Mn alloy reacting with nitrogen is faster.