Study on the Forming-Ability of Metastable Phases in Vapor Quenched Alloys Using High Temperatrue X-ray Diffraction

在本计画中，我们研究了溅镀非平衡合金的结构与物性与温度的关系（高能态的汽相淬灭过程），得到了如下结果：1）利用本项目引进的安装在X射线衍射装置上的高温样品台，2）对直流对靶溅射制备的Fe-Cu-Ag非晶态合金进行了X射线衍射、磁化强度、电阻率、差示扫描量热和穆斯堡尔谱的观察。非晶合金在400 K以上晶化，并转变为具有相同浓度的亚稳fcc相。在670 K以上，它们分离为纯bcc结构的Fe和纯fcc结构的Cu和Ag。3）我们观察了非平衡Fe-W合金的X射线衍射图、磁化强度和电阻率。富Fe bcc相的非平衡分离 ...更多信息 在770 K以上，α相和金属间化合物λ相的Fe含量增加。非晶相具有较高的热稳定性，晶化温度约为1170 K. 1170 K以上。它转变为λ相和bcc相，但没有转变为高温平衡相μ相。4）观察了非平衡Fe-Pd合金的X射线衍射图、磁化强度和磁致伸缩。在470 K以下，非平衡富Fe bcc相仍为亚稳相，但在470 ~ 570 K时，它分离为富Fe bcc相和富Pd fcc相。在570 K以上，相分离增强，无序的fcc相转变为L10型有序相.这些实验结果表明，在非平衡相转变为平衡相的过渡过程中，退火形成的亚稳相突破了基于平衡热力学的经典冶金学.我们打算做EXAFS和中子衍射的测量。少

In this project, we studied temperature-dependence of the structure and physical properties of nonequilibrium alloys produced by sputtering (vapor quenching process from high energy states) and obtained the following results.1) Using the high temperature sample stage, which was introduced by the present grant and installed on the X-ray diffraction equipment, we could observe X-ray diffraction patterns temperatures between 350 - 850 ^ﾟC.2) We observed X-ray diffraction patterns, magnetization, electrical resistivity, differential scanning calorimetry and Mossbauer spectra for amorphous Fe-Cu-Ag alloys produced by DC facing target type sputtering. The amorphous alloys crystallize above 400 K and transform to a metastable fcc phase with the same concentrations. They separate into pure bcc Fe and the pure fcc Cu and Ag above 670 K.3) We observed X-ray diffraction patterns, magnetization and electrical resistivity for nonequilibrium Fe-W alloys. The nonequilibrium Fe-rich bcc phase separate … More s into a more Fe-rich alpha phase and an intermetallic compound, the lambda phase, above 770 K. The amorphous phase displays high thermal stability and the crystallized temperature is about 1170 K. Above 1170 K. it transforms to the lambda phase and the bcc phase, but dose not transform to the mu phase which is the high temperature equilibrium phase.4) We observed X-ray diffraction patterns, magnetization and magnetostriction of nonequilibrium Fe-Pd alloys. The nonequilibrium Fe-rich bcc phase is maintained as a metastable phase below 470 K, but it separates into a more Fe-rich bcc phase and a Pd-rich fcc phase at 470 - 570 K. Above 570 K, moreover, the phase separation is enhanced and the disordered fcc phase becomes the L1_0 type ordered phase.These experimental results indicate that the metastable phase formation in the transient process from nonequilibrium phases to equilibrium phases by annealing breaks through the classical metallurgy based upon the equilibrium thermodynamics. We intend to do measurements of EXAFS and neutron diffractions. Less