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1.
 本文研究了Pd40Ni40P20块状非晶在4 GPa及常压下的晶化过程。得到了时间-温度转变图。结果表明:高压下样品的晶化温度明显升高,压力对原子的长程扩散及相分离熔体的粘性流动均有抑制作用。在接近熔点进行高压退火时,获得了单相过饱和固溶体。其晶体结构为面心立方。  相似文献   

2.
 在600~930 K,常压到7 GPa的范围内,对非晶(Fe0.99,Mo0.01)78Si9B13合金等温等压退火30 min。实验表明:其晶化产物α-Fe(Mo, Si)、Fe3B和Fe2B相的析出与所加压力密切相关。压力使非晶(Fe0.99,Mo0.01)78Si9B13合金的晶化温度和亚稳Fe3B相的析出温度下降,在一定的压力和温度下,亚稳Fe3B相将向稳定Fe2B相转变,其转变温度随压力而变化。还对非晶(Fe0.99,Mo0.01)78Si9B13合金的晶化和亚稳Fe3B到稳定Fe2B转变的热力学机制进行了讨论,并给出Fe3B向Fe2B的相转变方程。  相似文献   

3.
 研究了Fe78B13Si9、(Fe0.99Mo0.01)78B13Si9非晶合金的激波晶化行为。激波是由氢-氧爆炸产生的。实验结果表明:激波能使非晶合金在微秒时间内晶化,晶化主相为α-Fe基固溶体,次晶化相为Fe3Si,且观察到α-Fe基因溶体晶格常数变小。用DTA分析进一步证实:激波晶化是比较完全的,晶化相相当稳定。  相似文献   

4.
 高压下与Al发生扩散反应的非晶(Fe0.99Mo0.01)78Si9B13(FMSB)的晶化产物与纯FMSB的不同。与Al反应的FMSB非晶在3.0~5.0 GPa、780~900 K热处理时,晶化为α-Fe(Al)和次亚稳非晶合金;在这一压力范围以外,720~900 K热处理时,晶化为α-Fe(Si)、Fe3B或Fe2B。与Al发生反应的FMSB非晶可能通过与Al的扩散反应在Al/FMSB界面开始晶化。压力和温度对晶化过程的影响主要是由于α-Fe固溶体的Gibbs自由能随压力、温度和Al含量的变化。  相似文献   

5.
 研究了非晶(Fe0.99Mo0.01)78Si9B13(FMSB)合金的机械晶化过程和机制,并讨论了局域高压的作用。结果表明:非晶FMSB合金的晶化过程及其产物与球磨强度和球磨时间有密切关系,在低能球磨FMSB非晶过程中,晶化相只有α-Fe(Mo,Si)固溶体,而在高能球磨过程中,除了α-Fe(Mo,Si)固溶体结晶相之外,还分别有(Fe,Mo)3B和Fe2B相析出。其晶化机制可归因于由碰撞引起的局域高压和局域高温共同作用的结果。实验结果还表明,机械球磨不仅对非晶FMSB的常压热晶化温度有重要影响,而且对其热晶化结果亦有重要影响。  相似文献   

6.
非晶Fe78Si9B13合金在高压下的晶化   总被引:1,自引:0,他引:1       下载免费PDF全文
 本文研究了压力对Fe78Si9B13非晶合金晶化温度的影响。给出了常压及7.5 GPa压力下的时间-温度-相变图。结果指出:晶化温度不仅与压力的大小有关,而且还与热处理的时间因素有关。此外,高压下bcc-Fe(Si)相结晶区域明显变大。  相似文献   

7.
非晶合金Fe73.5Cu1Nb3Si13.5B9的激波晶化及其特征   总被引:3,自引:0,他引:3       下载免费PDF全文
 研究了非晶合金Fe73.5Cu1Nb3Si13.5B9(FINEMET)的激波晶化。与退火晶化比较,激波晶化具有一系列鲜明特征,这些特征是固态下扩散性相变理论难以解释的,有深刻的物理内涵。  相似文献   

8.
 X射线衍射和透射电镜的结果表明:非晶FeCuNbMSiB(M=Nb,V,Mo)合金在540 ℃退火20 min,表面析出的纳米晶是α-FeSi固溶体,粒度为10~20 nm。此外,在0.000 1~2.4 GPa范围内测量了它们的常压室温电阻率以及电阻率随静水压的变化,得到了电阻率与压力的线性关系式。最后探讨了热处理方式和温度对非晶Fe73.1Cu1.2Nb3.2Si12.5B10合金退火形成纳米晶的影响。  相似文献   

9.
 本文详细介绍了在0.000 1~2.3 GPa流体静压力下测量三种非晶合金饱和磁感应强度Bs和最大磁导率μmax的实验方法。实验结果表明:三种非晶合金受压后Bs和μmax表现各异,可归为两大类。(1)第一类压磁效应:总趋势是Bs和μmax都随压力增加而下降,但在几个压力区Bs反常增高。如Fe75Ni5Si5B15非晶合金Bs随压力增加均匀下降,(Fe0.85Co0.15)Cu0.4Si4.4B13.2非晶合金的Bs随压力增加降—升—再降。(2)第二类压磁效应,如Fe78.75Cu1.25Si5B15非晶合金的Bs和μmax随压力增加都有未见报导过的微弱升高。分别结合局域电子模型的交换作用理论和巡游电子模型的刚带理论进行了讨论。  相似文献   

10.
 在4 GPa,700~900 K温度范围内研究了Al与非晶(Fe0.99, Mo0.01)78Si9B13合金的固态反应过程。利用透射电镜、X射线衍射仪和扫描电镜研究了Al与非晶(Fe0.99, Mo0.01)78Si9B13合金界面所形成的扩散层的微观结构。在780~840 K温度范围内形成的扩散层中观察到Al-Fe基玻璃合金,其晶化温度为870 K左右。还对Al-Fe基玻璃合金的形成机理进行了研究。  相似文献   

11.
J. J. Suñol 《哲学杂志》2013,93(20):2323-2342
Progress in the ball milling amorphization of elemental powders with the overall composition Fe40Ni40P20 ? xSix (X = 6, 10 and 14) and thermally induced crystallization of obtained alloys were characterized by differential scanning calorimetry, X-ray diffraction and transmission Mössbauer spectroscopy (TMS). Diffusion of Si into Fe and Ni alloys promotes the formation of the amorphous phase, via previous formation of (Fe, Ni) phosphides. After milling for 32–64 h, most of the powders are amorphous but bcc Fe(Si) crystallites remain (about 5% in volume). TMS results indicate that homogenization of the amorphous phase occurs by interdiffusion of Ni and Fe in Fe(Si,P)-rich and Ni(Si,P)-rich zones respectively. Annealing induces structural relaxation of stresses induced by milling, growth of bcc Fe(Si) crystallites, precipitation of bcc Fe(Si) and fcc Ni–Fe, and minor phases of Ni-rich silicides and (Fe, Ni) phosphides. The main ferromagnetic phase is bcc Fe(Si) for Fe40Ni40P10Si10 powders obtained after milling for 32 h. However, it is fcc Fe–Ni for the same alloy after milling for 64 h. In the later powders, as well as for alloys with x = 6 and 14 milled for 32 h, the fcc Fe–Ni shows the Invar magnetic collapse.  相似文献   

12.
 本文采用高压X光衍射方法在金刚石对顶压砧中在位地(in situ)研究了Fe68Co24Ni8(wt%)合金在室温下的压致bcc→hcp结构相变和直到40.5 GPa的等温压缩行为。实验结果表明该合金在常压下为bcc结构,晶格常数a0=(0.287 0±0.000 1) nm,体积V0=(7.119±0.007) cm3/mol,密度ρ0=(7.981±0.008) g/cm3;在20.9 GPa附近出现bcc→hcp结构相变,两相共存压力区约10 GPa,在此区域内有晶面间距d(002)hcp=d(110)bcc,且原子平面(002)hcp//(110)bcc,hcp相比bcc相体积减小(0.33±0.02) cm3/mol;高压相hcp结构的晶格参数比值c/a=1.608±0.004;相变后原子配位数的增加使得hcp相(002)平面内及(002)平面间的最近邻原子间距比bcc相最近邻原子间距分别增大约1.6%和0.5%;用Murnaghan状态方程对实验数据进行最小二乘法拟合,得到bcc相B0=(130±13) GPa,B0'=12.6±0.5;hcp相V0=(6.62±0.04) cm3/mol,B0=(243±21) GPa,B0'=6.8±0.3;对于该合金的bcc→fcp相变时的结构转变机制做了详细的讨论。  相似文献   

13.
The hyperfine field distributions of amorphous Fe40Ni40PxB20?x (x=10, 12, 14, 17) samples before and after different heat treatments have been determined by means of Mössbauer spectroscopy. All of these P(H) curves are characterized by a main high field maximum and an additional low field maximum, respectively. The asymmetry of distributions of high field component in P(H) of Fe40Ni40PxB20?x increases progressively from Fe40Ni40P10B10 to Fe40Ni40P17B3. The distributions of low field component in P(H) are affected differently by the annealing temperature. The results indicate that the phospoorus element plays an important role in the hyperfine interactions of amorphous Fe40Ni40PxB20?x The influence of annealing atmosphere has been discussed.  相似文献   

14.
Amorphous alloys Fe8Ni80?XB20 (x=20?60) and (Fe0.5Ni0.5)100?yBy (y=16?25) have been thermally treated between 300k and 800k in a differential scanning calorimeter (DSC). The phases have been determined using Mössbauer spectroscopy and x-ray diffraction methods. The crystallization temperatures, heats of crystallization and the crystallization products of the amorphous(a)-Fe?Ni?B system vary with the composition of Fe and with the that of B. Basing on the variations of these factors the short range order (sro) of the amorphous Fe?Ni?B alloy system is discussed.  相似文献   

15.
This study has investigated the microstructure and magnetic properties of Fe40Ni38B18Mo4 at various degrees of crystallization from the amorphous state. TEM and XRD studies confirmed that phases forming after crystallization at temperatures around 414 and 522 °C were cubic (Fe, Ni, Mo)23B6 phase and FCC (Fe, Ni) solid solution. The growth behavior and morphology of the nanocrystalline phases have been studied as a function of time and temperature. Nanoparticles were lying in the size range of 10–20 nm and they were stable below 522 °C. Kissinger approach, Ozawa method and Yi Qun Gao method were employed to determine and compare the kinetic parameters of the crystallization processes. A growth mechanism of crystallizing phases was proposed on the basis of these results. Magnetic properties mainly coercivity and saturation magnetization of as-received and heat-treated samples were evaluated.  相似文献   

16.
We report measurements of the electrical resistivity of the amorphous alloys Fe40Ni40P14B6 (Metglas 2826). Fe32Ni36Cr14P12B6 (Metglas 2826A) Fe80B20 (Metglas 2605) and Fe75B25 as a function of pressure and temperature. The pressure is varied between 0 and 12 GPa, the temperature between 1.2 and 380 K. At low temperatures the pressure dependence yields additional information on the scattering mechanism.  相似文献   

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