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The glass forming ability of binary TM-TM (TM = transition metal) alloys produced by mechanical alloying is studied with both two-dimensional maps of Miedema's coordinates and combinative coordinates. The former is constructed of Miedema's coordinates, the differences of electronegativities Delta phi and electron densities Delta n(ws)(1/3); the latter is constructed of the ratio Delta phi/Delta n(ws)(1/3) and size factor(R(1) - R(2))/R(2). In these maps, binary systems which formed amorphous phase are clearly separated from the non-formed systems by a curve. The equations of the curves are y = 3.825x, and y = 2.52x(-1/4) for the pure Miedema coordinates and combinative coordinates, respectively.

Amorphous Zn-Ti was successfully synthesized for the first time by mechanical alloying of pure elemental powders of Zn and Ti using a planetary high energy ball mill. The structure and thermal stability of the alloy were analysed by X-ray diffraction, differential scanning calorimetry and high temperature X-ray diffraction. The results indicate that the large negative enthalpy of formation for the Zn-Ti system supplies the driving force for the solid state amorphization reaction. Moreover, the Zn atom is also a fast-moving species in the Ti-Zn system and ensures the success of amorphization. The crystallization sequence of the amorphous Zn 60 Ti 40 alloy is that Zn 2 Ti appears first and then a γ phase forms. The activation energies for the two processes are 1.106 and 1.620 eV respectively.

A two-dimensional scheme is constructed in order to predict the possibility of amorphization of binary transition-metal systems by mechanical alloying. The two coordinates of the scheme are the size factor (RA-RB)/RA, and the enthalpy of formation of the amorphous phase Delta Hfa, which is calculated from the Miedema model. In this scheme amorphous and nonamorphous regions can be separated by the empirical line Delta R/R=0.068 Delta Hfa+0.716. The investigation is an advance in the quantitative prediction of glass-forming ability using a mechanical alloying technique.

Binary Zn-TM (TM = Zr, Nb, Mo) alloys have been prepared by mechanical alloying from elemental powders in a planetary ball mill. The structure and thermal behaviour were investigated by X-ray diffraction and differential thermal analysis. Completely amorphous powders were obtained in the Zn-Zr and Zn-Nb systems, whereas for the Zn-Mo system mechanical alloying results in a crystalline Mo-based solid solution. Furthermore the factors related to the possibility and rate of amorphization were discussed.

An amorphous Zn60Zr40 alloy was synthesized for the first time by mechanical alloying of pure elemental powders of Zn and Zr using a planetary high-energy ball mill. The structure and thermal behaviour were analysed by X-ray diffraction and differential thermal analysis. The result indicates that the large negative enthalpy of formation of Zn-Zr provides the necessary driving force for solid-state amorphization. In addition, the realization of the amorphization of Zn-Zr shows that Zn is a fast-moving species in host Zr although the ratio of Vimp(Zn)/V(Zr) is larger than the critical value of the Zr-TM (3d) system, 0.58. The activation energy of crystallization of the glass is about 3.068 eV.

The amorphous Cu60Ti40-xZrx (x=0, 10, 20, and 30) alloys were successfully synthesized by mechanical alloying of pure elemental powders of Cu, Ti and Zr using a planetary high-energy ball mill. The structure and thermal behaviour of these alloys were analysed by X-ray diffraction and differential scanning calorimetry. The results indicate that the replacement of Ti by Zr increases the chemical driving force of the amorphization reaction and the interaction of dissimilar atoms of the Cu-Ti-Zr ternary system. Thus, the glass-forming tendency, the amorphization rate and the stability are all improved. In addition, the stability of Cu-Ti-Zr amorphous powders is related to the crystallization sequence and the first crystallization phase.

The structural change of metallic glass Cu45Ti55 from room temperature to 800 K is investigated by combining internal friction using the torsion penulum method with X-ray diffraction (XRD), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). The internal friction curve exhibits a point of inflection at about 640 K and an internal friction peak between 640 and 780 K, which corresponds to the precipitation of CuTi2 (tetragonal) and a metastable phase I (tetragonal) and the formation of CuTi (tetragonal), respectively. The result shows that internal friction is closely related to the phase transition during crystallization, and there is much correspondence between internal friction and DSC in describing the crystallization behavior of metallic glasses.

The crystallization behaviour of the metallic glass Cu73.9Ni9.2Sn3.5P13.4 has been investigated by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Three exothermic peaks occur at 216, 295 and 365 degrees C. Based on the exothermic peaks and observations from XRD at various stages of crystallization, the crystallization sequence and the structure of the crystallization phase of the glass is described.

An amorphous Cu71.3Ni12P16.7 alloy was prepared by means of melt spinning. The crystallization behaviour of the alloy was investigated using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Three exothermic peaks were observed at 235, 280 and 300 °C, respectively. Analyses from XRD at various stages of isochronal crystallization indicate that the crystallization process and transition products of the glass can be shown as following: amorphous → Cu3(hexagonal) + copper(fcc) → Cu3P + copper + Ni2P(tetragonal) + Ni12P5(tetragonal) → Cu3P + copper + Ni3P(tetragonal).

The effect of nickel concentration in rapidly quenched ${\mathrm{Cu}}_{83.3\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ni}}_{\mathit{x}}$${\mathrm{P}}_{16.7}$ ternary alloys on glass formation and stability was investigated by x-ray diffraction and differential scanning calorimetry. In the present work, the glass-forming range was found to be x=10\char21{}16 at. % Ni. Estimates of the Gibbs free energy and activation energy of the crystallization process indicate that the driving force decreases and the potential barrier of crystallization increases with increasing nickel content, thereby increasing the stability of the amorphous state. This may be attributed to the formation of stronger Ni-P bonds and partial bonds formed by overlapping s-p hybrid orbitals and to the strengthening of the s-p-d orbitals of Cu and Ni with decreasing d-electron concentration.

A non-isothermal method has been developed to measure the Avrami exponent of crystallization in metallic glass based on the Johnson-Mehl-Avrami isothermal equation. An example of metallic glass Cu73.8P13.8Ni8.3Sn4.1 was studied with non-isothermal and isothermal kinetic analysis for determining the Avrami exponent,n, which are 3.5 and 3.4, respectively, and are comparable.

In the work reported here we investigated the effects of variations in the concentration of the metalloid element phosphorus on the formation and the thermal stability of Cu-Ni-P ternary glassy alloys prepared by melt-spinning

The effect of thermomechanical treatment on the d.c.-etching efficiency of aluminium anode foils for high voltage capacitors was investigated with strip-cast aluminium. The structure factors which influence the etch morphology, and the relationship between the etch morphology and the specific capacitance were analysed. The model of calculating the specific capacitance from the etch morphology was built up, and the condition of ideal morphology derived. The characteristics of distribution for trace impurity elements were indicated by secondary ion mass spectrometry, and the nucleation of the impurity elements for d.c.-etching was discussed.

Many infrared optical systems usually adopt catoptric systems. Because that the system does not have chromatism and restriction of the working wave. But the coma and astigmatism of off-axis point is large, so the field of view that we can use is restricted. In the needs of infrared early warning system for sea-based, a large field of catadioptric infrared optical system is designed. The optical system breaks the limitation of traditional reflective optical system with small field of view. The system adopts two methods to expand the field of view. One is adding the calibration group before the reflecting system .The other one is that the primary and secondary reflective mirror system are used of Mangin mirror. So the optical system avoids any high-order aspheric surface .In order to match the cold aperture exactly, lens group is inserted after the first image plane. The system's field can reach 8 degree, and the ratio of obscuration is less than 0.4, and also optical transfer function achieves diffraction limit.