This paper describes the theory of elasto-plastic FEM for large strain and themathematical model of the contact problems on the dynamic boundary. And it presents thesimulation results of the ring compression by using the elasto-plastic FEM program ANSYS 5.1 and the material constitutive relationship in hot metal working. The theoretical calibration curves of determining the friction coeffcient for 6:3:2 rings have been predicted.The equivalent strain and theshear stress distributions have been presented.

Specimens made of fully annealed or plastically deformed polycrystalline nickel are hydrogen charged. The properties and recovery behaviour of the hydrogen induced defects are studied by means of positron annihilation. The measured activation energy for migration of a vacancy is 0.96±0.05 eV. The results showed that both for the fully annealed and plastically deformed polycrystalline nickel, the parameter S and the average lifetime will increase sharply when the specimens were hydrogen charged. The type of the hydrogen charged defects depends on the state of the specimen before charging, in a fully annealed specimen, except some of vacancies and dislocations, the main hydrogen charged defects are the micro voids or the micro cracks, which can not be recovered at above 650℃. Compared with the annealed samples, the hydrogen induced defects are mainly vacancies, dislocations and vacancy clusters, and the microvoids was not found in the deformed nickel specimen.

The influence of PED (pulse electric discharging) on the solidified structure of Sn-10%Pb (mass fraction) hypoeutectic has been studied. The testing results show that the PED can modify the solidified structure from large grains with Sn-rich dendrites to finer grains with nearly globular crystals. A phenomenological mechanism has been proposed to approach how the PED affects the microstructure. The relationships between the pulse pressure and pulse current, and between the nucleation rate and pulse pressure have been derived using the classical homogeneous nucleation theory and electrodynamic theory. The different results, tested here and elsewhere, may result from the different influence of PED on nucleation and growth of grains because of the different pulse pressure with various PED.

By means of Mossbauer spectroscopy analyses, it is indicated that there are three kinds of configurations for Fe atoms corresponding to α-Al(Fe) and α-Al(Fe-Fe) solid solutions and α-Al13(Fe,V)3Si intermetallic compound in liquid-quenched Al-Fe-V-Si alloys. Except for the absence of α-Al(Fe-Fe) configuration in Al93.3Fe4.3V0.7Si1.7 alloy, the other Fe atomic configurations do not change during the annealing at 755 K for 500 h. However,the relative contents of these configurations have changed. The lattice parameters of α-Al matrix decreased with increasing Fe content (4.3, 5.4, 6.4 (atomic fracti0n, %)) for three RS Al-Fe-V-Si alloys in as-cast and heat-treated states. In addition, the possible configurations of V and Si atoms have been discussed by using the results of Mossbauer spectra and matrix lattice parameters.

Commercial grain oriented silicon steel was cold rolled from 0. 746 mm to 0.34 mm, by cross shear rolling with a roll mismatch speed ratio 1.17, after first cold rolling and intermediate annealing as normal. The subsequent annealing was just as that in industry. The texture distribution and development through the thickness were researched by ODF and reverse pole figure quantitative analyses, and the magnetic properties were measured. The results indicate that the deformation texture is similar to that obtained by traditional one,favorable deformation texture can also be found near the both outer layers of sheet, but they deviate obviously to the fast speed roll. Therefore, the deformation texture shows an asymmetry distribution through the thickness. After decarbon annealing, η-fibre increases,texture with a symmetry distribution reappears through the thickness: sharp Goss texture forms after the secondary recrystallization annealing, and the magnetic properties measured are not lower than that rolled by traditional one.

The thin-wall effect of a directionally solidified superalloy has been studied by using tubular hollow specimens (wall thickness l= 0.8, 1.2,1.6 mm) whose shape and thickness are similar to the hollow turbine blades made by the near-shape investigation cast procedure.The results show that stress-rupture properties of thin-wall specimens are not reduced remarkably comparing that of the standard ones (5 mm diamater), i.e., thin-wall effect of this alloy is not remarkable in this experiment. The results differing from that of previous works are discussed in term of cast process and microstructure.

Being aimed at the RSC (Reversed Sigmoidal Curves) characteristic of metal fracture Profile fractal chart, the differantial curve of fractal chart was studied by means of S600 data image processing system. A model of P-spectrum and some characteristic parameters which gave an overall description of the Profile fractal were proposed and used in the statistical analysis of the Profile and rupture mechanism reserarch of ductile iron fracture.

By analysing the kinetics of planetary ball milling, the impact behavior of milling ball is investigated, theoretical relationships between the technical parameters of ball milling (RBP= ball to powder ratio,Ω: angular velocity of milling and rb: radius of ball) and the velocity (vb), average free path (S) and impact frequency (f) of milling ball are established in this paper, It shows that vb and f increase with increasing angular velocity of milling; keeping the mass of powders invariable,f increases with increasing RBP, however, vb and S decrease;when mP and RBP are constant, S decreases and f increases with decreasing rb.

The quantitative analysis for fatigue fractography can be realized through the suitable image transform of fatigue fractographs, from which some useful characteristics can be obtained. Two-dimensional discrete Fourier transform is used in the process of fatigue fractograph, and the important characteristics to describe the texture and direction features on a fatigue fracture surface are abstracted from the Fourier power spectrum. A two-dimensional image analysis problem can be simplified as a one-dimensional characteristic curve analysis. The results show that some important characteristics on a fatigue fracture surface can be obtained in space frequency domain by means of two-dimensional discrete Fourier transform, which are impossibly acquired in space domain of fractograph. The method presented in this paper is identified to be a new way to carry out quantitative analysis of fatigue fractography.

Mutual separation of neighboring rare earth elements has been investigated from their binary chloride mixtures LaCl3-CeCl3, CeCl3-PrCl3, PrCl3-NdCl3 and their quaternary chloride mixtures LaCl3-CeCl3-PrCl3-NdCl3 by using a dry process (i.e. chemical vapour transport process), in which the aluminium chloride is selected as complex former.The separation factors from the binary chloride mixtures are 12.3 for La : Ce, 5.79 for Pr:Ce and 1.32 for Pr: Nd. An higher separation factor of Pr:Nd=1.98 was also observed from their quaternary chloride mixture.

The phase diagram of KPO3-MoO3 binary system has been determined by means of visual polythermal, DTA and X-ray diffraction analyses. It was found that two compounds formed in this binary system, their stoichiometrical formula are KPO3MoO3 and 3KPO3 MoO3, respectively. The existence of two compounds has been also proved by Raman spectrum analysis.

The surface morphologies and microstructures as well as phase compositions of scale on the alloy Ni20Cr and the alloy implanted by Y+ (with the dose of 1×1O15,2×1016 and 1×1017 Y/ cm2 respectively) oxidized in air at 1000℃ have been investigated by means of SEM / EDS, XRD and TEM / EDS. It was found that all the scale of alloy Ni20Cr with and without yttrium implantation were composed of larger grained NiO, NiCr2O4 and finer grained Cr2O3, and among of which small pores were created at the triangular junctions of grain boundaries of NiO. The implanted yttrium ions over 2×1016/cm2 increased the volume fraction of Cr-containing oxide, in which yttrium, most of which formed small Y-containing oxide particles, was detected. According to the experimental results, it was believed that in the initial oxidation stage yttrium oxidized in preference to alloy elements and formed fine oxide particles (10-20nm), and sequentially the particles may not only promote the nucleation and growth for Cr2O3 also produce Y ions segregated to its grain boundaries due to the partial dissolution of the particles itselves, the latter was beneficial to decrease the scale growth rate as well as improve its mechanical properties for the reason that segragated Y ions may inhibit the Cr3+ out-diffusion along "short-circuit' and enhance the cohesion between oxide grains.

Nickel-Chromizing was conducted for carbon steel samples (mass fraction:0.1%, 0.45%, 0.8%) using the technique of glow-discharge ion surface alloying with arc sources. By using X-ray diffraction, SEM and TEM, the phase structure and the distribution of alloying elements (Cr, Ni, C) in the alloying layer were studied. The results indicated that the surface concentration of nickel and chromium is 50%-60% and 10%-15% respectivaly;the concentration of alloying elements in alloying layer decressed gradually from surface to inner; the distribution of carbon in alloying layer of samples with different carbon-contents is different; the alloying layer isγ-(Fe,Ni) for steel 10, and there were Cr23C6 and Cr7C3 in γmatrix alloying layer of steel 45, T8 sample.

Bright layers covering 80 % of the melt area have been achieved by laser glazing on Fe-C-Si-B eutectic matrix prealloyed by laser on nodular iron substrates, which are verifled to be metallic glasses by electron diffraction. It is demonstrated in the paper that epitaxial growth from the crystalline substrate at melt bottom is the most critical factor during laser glazing. The chief condition for glass forming is the abrupt stop of the epitaxial growth during solidification, which is dependent upon the eutectic composition, composition homogeneity, fine microstructure, laser glazing power density and scanning velocity.

In present work nanocrystalline supersaturated solid solutions (NSSS) with bcc and fcc structures were prepared in Fe-rich and Curich compostion of immiscible Fe-Cu system respectively by mechanical alloying. The effects of grain size and composition on the hardness of Fe-Cu NSSS have been studied by X-ray diffraction and Vickers hardness measurement. It has been found that the hardness of NSSS formed in Cu-rich composition increases with the increase of Fe, its solute atom content. On the contrary, the hardness of NSSS formed in Fe-rich composition decreases with the increase in Cu content.The hardenning and softenning caused by the dissolving of Fe and Cu respectively have been discussed based on the structure feature of NSSS and estimation of the strength of grain boundary and crystal components of NSSS.

The magnetism of bulk polycrystal NiAl and nanostructural NiAl with various grain diameter was studied. The susceptibility of a bulk polycrystal NiAl X is about 3.0×10-3 / g, its specific magnetization σ has almost not change with temperature. The σof as condensed nanostructural NiAl samples with average grain size of 8.6 nm, diminishes obviously with the increase in temperature at a range of 1.5 -150 K, from tis σ-T curve we get the Curie temperature TC of the sample being about 124 K. Other three samples obtained by annealed the condensed NiAl samples at various temperatures have average grain sizes of 12,18 and 21 nm, their a are two orders of magnitude larger than that of the bulk polycrystal NiAl, change slightly with temperature at range of 1.5-300 K. The experimental results indicate that there exists nonmagnetism-magnetism transition between polycrystal NiAl alloy and nanostructural NiAl.

The interfacial reaction and its mechanism during the solidification process of CF/Al-4.5Cu metal matrix composite produced by squeeze casting method were studied.When the temperature of interfacial reaction is above 773 K, Al4C3 phase was formed spontaneously, and the activation energy of reaction, Q, is about 254 kJ / mol. The regular pattern of crystallization and growth of Al4C3 phase shows that Al4C3 phase nucleated on the surface of carbon fiber (CF) first, then the carbon atom travels along the new formed Al4C3 phase or melted aluminum alloy. On the meanwhile, the Al atoms diffuse through the Al4Ca phase boundaries, interstices and defects among Cu atoms, or between Cu and Al atoms.The shape of Al4C3 phase is stick-like. The CuAl2 phase has also formed, and it nucleates on the surface of CF or Al4C3 phase and grows gradually by eutectic reaction. In addition, a theoretical model of reaction mechanism in the interface of CF/Al-4.5Cu metal matrix composites is suggested, the whole reaction process can be divided into four stages: (1)Forming active sites on the CF surface; (2) Al4C3 phase has nucleated at the active sites; (3)Al4C3 phase grows continuously, and CuAl2 phase nucleat; (4) CuAl2 phase grows continuously.

As to the ZA22/Al2O3(F) composites made by squeeze casting, the room-temperature strengths were studied by the computer simulation with ROM rule and neural network model alternatively. The results show that ROM rule can predict two important parameters of composites strength e.g. Vmin and Vcrit effectively. Compared with ROM rule, neural network model can not only predict the Vmin and Vcrit pretty well, but also describe the strength variation with the change of Vf.

A software for determinating the thickness of thin metal film with EPMA was developed on the bass of Sewell's formula. It is based physically on that the exciting depth of X-ray decreased as the accelerate voltage of incident electron lowered. When the exciting depth is equal to the film depth, the ratio of X-ray intensities from film and bulk standard is unity. The thicknesses of several thin metal films of pure elements on Si and Al substrates were determined by this method, and the relative error of mass thickness is smaller than 1.6%.The minimum mass thicknesses for various elements, which can be measured, were also obtained.