Zr对Pr-Fe-B非晶合金晶化形成纳米晶合金的作用

从非晶合金化激活能的角度，分析了Pr-Fe-B非晶合金在退火过程中晶粒粗大的原因，揭示了Zr元素在其晶化过程中的作用，结果表明，Zr能改变Pr-Fe-B非晶合金中α－Fe相的晶化行为，有助于形成尺寸细小的α-Fe相。     

预退火对Sm5 Fe74.3Nb1.5Si11.7 B4.5C2.5Cu0.5非晶合金晶化动力学的影响

研究了预退火对Sm5Fe74.3Nb1.5Si11.7B4.5C2.5Cu0.5非晶合金晶化动力学的影响。结果表明，预退火处理使非晶合金晶化相α-Fe和Sm2Fe17Cx的晶化温度（Tp）和晶化表观激活能（Ec）值降低，且改变晶化相α-Fe在晶化过程中晶化激活能的变化趋势，有助于该合金在晶化退火中形成晶粒尺寸较小的α-Fe相。     

Co对Nd-Fe-Al大块非晶合金的晶化行为和磁性能的影响

采用示差扫描量热法(DSC)，X射线衍射(XRD)和振动样品磁强计(VSM)研究了Co对Nd—Fe-Al大块非晶合金的非晶形成能力，晶化行为和磁性能的影响。结果表明：加入Co元素后可以显著提高Nd—Fe-Al大块非晶合金的非晶形成能力以及提高合金的居里温度。Nd60Fe30-xAl10Cox(z=0、5、10)大块非晶合金在室温有较高的内禀矫顽力，具有硬磁性。内禀矫顽力随着Co含量的增加变化不大．但是饱和磁化强度和剩磁则随着Co含量的增加有所下降。Nd60Fe3-xAl10Cox(x=0、5、10)大块非晶合金具有的硬磁性能来自于非晶相。合金少量晶化后，磁性能变化不大。完全晶化后合金的硬磁性迅速消失。     

离子束辅助沉积技术制备非晶合金薄膜

本阐述了用离子束辅助沉积（IBAD）技术制备非晶合金薄膜的基本思路，介绍了本研究组在二元合金系统里制备和非晶和亚稳晶相的研究结果，研究发现，在所选的几个系统里采用IBAD技术均实现了非晶化，还发现了某些新相形成和相溶化现象，表现出与多层膜离子束混合（IM）不同的相形成规律，二元系统的形成热、组元金属的晶体结构和辅助离子束的能量对相的形成的均有重要的影响，这些研究表明IBAD技术在二元合金系统中制备与研究非晶合金薄膜以及亚稳晶态薄膜方面具有很大的应用前景和理论意义。     

弛豫对Zr-Al-Ni-Cu基非晶合金晶化过程的影响

非晶合金的稳定性是制备大块非晶合金的关键，而弛豫后形成的短程有序结构对非晶中的晶体相形核有重要的影响。本文通过差热分析及X射线衍射法研究了预先弛豫处理对Zr60Al8Ni12.5Cu17Si2.5和Zr60Al8Ni10Cu17Si5非晶合金晶化过程的影响。结果表明：预先弛豫处理降低了上述非晶合金的稳定性。Si含量的增加则提高上述非晶合金的稳定性。根据等温转变过程日体相形核孕育期采用Arrhenius公式所确定的晶化激活能更能反映非晶晶化过程及非晶的稳定性。     

Fe70Zr10B20非晶合金的制备及其热稳定性和磁性能研究

采用机械合金化技术制备了Fe70Zr10B2。磁性非晶合金粉末。分析Fe70Zr10B20非晶合金的形成机制、晶化机制：研究Fe70Cr10B20非晶合金不同热处理温度下的磁性及球磨过程中样品的磁性。结果表明：Fe70Cr10B20非晶相的形成是由原子的扩散和晶格崩渍共同作用的结果；Fe70Cr10B20非晶合金的热致晶化模式为一次晶化；球磨过程厦非晶熟处理后样品的磁性与其结构、晶粒尺寸、应力和缺陷等因素有关。     

机械合金化Fe—B非晶合金及纳米合金的形成

在适当条件下机械合金化可以形成急冷法难以得到的单一Ｆｅ６０Ｂ４０非晶合金，而在其他成分内形成亚稳纳米合金，在众多的球磨条件中，球磨机的转速是控制合金化的重要因素。空气中的氧对小颗粒界面产生了强烈的污染作用，从而抑的原子的相互扩散，难以形成单一的非晶产物，不同球磨条件下的产物含有的非晶相的晶化温度比单一非上合金的晶化温度稍高，并且与球磨条件以及成分的关系不大。     

激波对多层非晶合金的作用及影响

研究了激波对以非晶（Fe0.99MO0.1)78B13Si9,Fe73.5Cu1Nb3Si13.5B9合金的作用,发现激波可使多层非晶合金晶化。晶化主相α－Fe的晶粒尺寸,晶格常数比单纯退火晶化、激波处理后退火的小。这是由于再结晶和形成不同固溶体（缺位式固溶体和替代式固溶体）引起的。并讨论了压力和温度在非晶激波晶化中的作用。     

溅射非晶钴硅薄膜的晶化过程及其分析

利用射频磁控溅射方法制备了具有CoSi2成分的非晶薄膜，对非晶薄膜的晶化过程进行了原位X射线分析。结果显示，溅射态薄膜为非晶态，而自由能一成分曲线说明非晶态合金有较低自由能。在非晶晶化过程中初生相为CoSi相，其形成由有效形成热（EHF）因素和结构因素决定。随加热温度升高，非晶薄膜晶化最终得到晶体CoSi2薄膜。     

Cu—Ge 非晶薄膜的形成与晶化研究

采用液氮冷却基片的气相沉积法,制备了 Cu-Ge 非晶薄膜。电阻测量及 TEM 形貌、电子衍射等分析表明,非晶态合金的形成能力及稳定性与成分密切相关。对 Cu_(100-x)Ge_x 合金膜,在x<25成分区,形成的非晶态稳定性差,晶化初期出现 fcc 结构的亚稳晶相;在 x>25成分区,有较高稳定性的非晶相形成,晶化后形成 Cu_3Ge 相。用合金化化学键效应观点解释了非晶态的形成、结构及结构转变行为。     

高强度低密度大模量菲晶态Ai—Li合金

利用单辊快速凝固装置制备出高强度、低密度、大楼量的非晶态Ａｌ６１Ｌｉ２．５Ｙ２５Ｎｉ１１．５（ｗｔ－％）合金，其最大拉伸断裂强度、显微硬度和弹性模量分别为１０３９ＭＰａ、４８８ＤＰＮ和９８．７ＧＰａ．与同成分的晶态合金相比，具有较高的电极电位、较宽的电压钝化区，其腐蚀抗力为晶态合金的７倍．在恒加热速率的晶化过程中出现４个晶化峰，晶化激活能的计算表明，Ａｌ６１Ｌｉ２．５Ｙ２５Ｎｉ１１．５非晶合金的晶化过程为一级反应．     

Rapid solidification of zirconium-based alloys

Zr based metal-metal binary and ternary alloys can be obtained in the amorphous state in very wide composition ranges. Several eutectic reactions and intermetallic compounds are present in these alloy systems which provide opportunities for examining the validity of different theories on glass formation. The amorphous phases in these alloys decompose by a variety of crystallization mechanisms. Instances of polymorphic, primary and eutectic crystallization have been encountered in these glasses. Zr-based metallic glasses possess excellent corrosion resistance and mechanical properties. In several studies their properties have been compared with that of their crystalline counterparts and interesting differences have emerged. In the solute lean Zr-based alloys very large freezing ranges are available for studying the liquid to solid transformation. It has been possible to study the formation of some of the low temperature phases directly from the liquid. This paper describes some of the aforementationed studies carried out on Zr-based amorphous and crystalline alloys.     

Crystallization studies on amorphous AI-Y-Ni and AI-Y-Cu alloys

AI₈₃Y₁₀Ni₇, AI₈₀Y₁₀Ni₁₀ and AI₈₀Y₁₀Cu₁₀ alloys were studied by the rapid solidification processing route. The glass-forming ability was found to decrease in the order of alloys mentioned above. Differential scanning calorimetry (DSC) of these amorphous alloys showed that the amorphous phase in AI-Y-Ni alloys has a higher thermal stability when compared to that in AI-Y-Cu alloys. A four-stage crystallization sequence could be identified for the AI-Y-Ni amorphous alloys. Even though the AI₈₀Y₁₀Cu₁₀ alloy showed four exothermic peaks in the DSC study, a definite crystallization sequence could not be arrived at due to the coexistence of many crystalline phases along with the amorphous phase in the melt-spun condition.     

Crystallization embrittlement of Ni-Si-B alloys

Changes in the mechanical properties, and in particular the loss of ductility, have been examined during the crystallization of a series of Ni-Si-B amorphous alloys and an Ni-Fe-Si-B alloy. In all cases crystallization takes place by the formation of large numbers of small crystals and at some stage during the crystallization process embrittlement occurs. The geometrical characteristics of the crystal phases, and the mechanical properties of the crystalline and amorphous components are assessed in an attempt to define the factors leading to embrittlement. Sensitivity to embrittlement does not seem to be related to the particular phase nature, geometry nor distribution of the crystals formed. Rather, the mechanical properties of the crystals seem to be the determining factors. Hard and brittle crystals lead to alloy embrittlement; soft, ductile crystals can lead to enhanced toughness of the alloys.     

Effect of Rare Earth and Transition Metal Elements on the Glass Forming Ability of Mechanical Alloyed Al–TM–RE Based Amorphous Alloys

The present work aims to compare the amorphous phase forming ability of ternary and quaternary Al based alloys(Al86Ni8Y6, Al86Ni6Y6Co2, Al86Ni8La6 and Al86Ni8Y4.5La1.5) synthesized via mechanical alloying by varying the composition, i.e. fully or partially replacing rare earth(RE) and transition metal(TM) elements based on similar atomic radii and coordination number. X-ray diffraction and high resolution transmission electron microscopy study revealed that the amorphization process occurred through formation of various intermetallic phases and nanocrystalline FCC Al. Fully amorphous phase was obtained for the alloys not containing lanthanum, whereas the other alloys containing La showed partial amorphization with reappearance of intermetallic phases attributed to mechanical crystallization. Differential scanning calorimetry study confirmed better thermal stability with wider transformation temperature for the alloys without La.     

Structural evolution during mechanical milling and subsequent annealing of Cu–Ni–Al–Co–Cr–Fe–Ti alloys

This study reports the structural evolution of high-entropy alloys from elemental materials to amorphous phases during mechanical alloying, and further, to equilibrium phases during subsequent thermal annealing. Four alloys from quaternary Cu_0.5NiAlCo to septenary Cu_0.5NiAlCoCrFeTi were analyzed. Microstructure examinations reveal that during mechanical alloying, Cu and Ni first formed a solid solution, and then other elements gradually dissolved into the solid solution which was finally transformed into amorphous structures after prolonged milling. During thermal annealing, recovery of the amorphous powders begins at 100 °C, crystallization occurs at 250–280 °C, and precipitation and grain growth of equilibrium phases occur at higher temperatures. The glass transition temperature usually observed in bulk amorphous alloys was not observed in the present amorphous phases. These structural evolution reveal three physical significances for high-entropy alloys: (1) the annealed state of amorphous powders produces simple equilibrium solid solution phases instead of complex phases, confirming the high-entropy effect; (2) amorphization caused by mechanical milling still meets the minimum criterion for amorphization based on topological instability proposed by Egami; and (3) the nonexistence of a glass transition temperature suggests that Inoue's rules for bulk amorphous alloys are still crucial for the existence of glass transition for a high-entropy amorphous alloy.     

Amorphization Behavior and Nanocrystalline Structure of Fe–P–Si–V Alloys

It is found that Fe–P–Si–V alloys tend to be in an amorphous state on cooling at a rate of 10⁵to 10⁶K/s. As compared to Fe–P–Si alloys, the crystallization behavior of the Fe–P–Si–V alloys is more complex owing to the formation of both metastable and equilibrium silicides. The metastable phases are nanocrystalline, as evidenced by transmission electron microscopy, which ensures a noticeable strength gain.     

Nanocrystals in Fe–P–Si–Mn Alloys

Annealing Fe–P–Si–Mn amorphous alloys is found to produce a few nanocrystalline phases, with a strength gain no higher than that in Fe–P–Si alloys. This crystallization behavior is accounted for by the formation of two metastable silicides whose growth rates during annealing are higher than those of the equilibrium phases.     

Ni,Fe对Al90TM5Ce5非晶合金稳定性的影响

本文研究了Al90 Fe5Ce5和A190 Ni5Ce5非晶合金及预峰在晶化过程和时效过程中的稳定性。Al90Fe5Ce5非晶合金的晶化开始温度TX 和时效稳定性比Al90 Ni5Ce5非晶合金高。Al90 Fe5Ce5非晶合金预峰所对应的化学短程序结构的稳定性较高 ,而Al90 Ni5Ce5非晶合金预峰所对应的化学短程序结构的稳定性差 ,甚至通过常温时效消失。非晶合金的稳定性与预峰所对应的化学短程序结构的稳定性有密切关系