Fe-Co melts with different Co contents were undercooled using fluxing purification method. With increasing the initial melt undercooling, grain refinement occurs twice in Fe100－x-Cox(x=10－40) alloy, except Fe90Co10. While the microstructure is no longer single phase and metastable phase appears when undercooling of the melt exceeds the critical undercooling. Moreover, except transition at low undercooling, the exact undercooling for microstructure transition and the critical undercooling for forming of metastable phase increase with the content of Co. Furthermore, BCT model and transient nucleation theory were applied to analyze the microstructure evolutions of Fe-Co alloy.

The grain boundary character distributions (GBCD) of Pb-0.05%Ca-1.5%Sn-0.026%Al （mass fraction）alloy, which was solution treated at 290℃ and solution treated followed by pre-ageing at 100℃～200℃ prior to the same strain annealing, were investigated by means of electron back scatter diffraction ( EBSD) techniques. The results indicate that special boundaries were largely populated in the specimen which was strain annealed just after solution treatment. The fractions of ∑3 and（∑9+∑27）boundaries reached 49.6% and 7.2%, respectively, and the connectivity of general high angle boundaries (HABs) network was interrupted substantially by the special boundaries. However, special boundaries of fairly low fraction were developed in the specimen which was strain annealed after solution treatment and pre-ageing. The fractions of ∑3 and（∑9+∑27）boundaries was less than 35.9% and 2.5%, respectively, and the connectivity of general high angle boundaries (HABs) network was not interrupted significantly.

Directional solidification studies have been carried out in transparent organic alloy CBr4-C2Cl6 system in order to obtain information related to influence of the sample thickness on the eutectic pattern formation and lamellar spacings adjustment mechanism in initial transient growth stage in eutectic systems. Thickness of the samples is within 16~100μm. Results showed that the capillary anisotropy affects considerably the eutectic grain formation when thickness equal to or less than 48μm due to eutectic grain consisting of titled lamellae will be form under such conditions. At the same time, in transient region the lamellar adjustment mechanism is sample thickness dependent remarkably, and which behaviors with bi-dimensional characteristics will be to occur only when sample thickness is 16μm or less.

Numerical simulation has a more and more important effect on improving directional solidification process. Because of the vacuum environment in the furnace where turbine blades are produced, radiative heat transfer plays a significant role in energy transportation. In traditional radiative heat transfer approaches, view factor calculation is a key step, so it takes too much time. Considering this point, Improved Monte Carlo Ray Tracing Approach has been developed. Because this approach combines the space division and the directional solidification features, the view factor calculation is avoided so that the time consuming is greatly shortened.The approach has been embedded in the self-developed software for turbine blade directional solidification temperature simulation. According to the experiments, the simulation results agreed well with the experimental.

The corrosion-resistant ultrahigh strength steel AerMet100 was fabricated by the laser melting deposition manufacturing technology. The as-solidification microstructure and mechanical properties of the laser deposited steel were investigated. The laser as-deposited steel has a rapidly solidified “zig-zag” full cellular structure and excellent room-temperature mechanical properties. The solidification mechanism of the zig-zag full cellular structure during the laser melting deposition process was discussed and a physical model based on selective epitaxial cell growth was proposed for the formation of the zig-zag full cellular structure.

High boron iron-base alloy is a new kind of wear-resistant material, which takes borides as wear-resistant phases. In structure, matrixes and borides were included in as-cast condition and the matrixes were changed with different alloying elements and quantity. Borides were distributed in the shape of continuous net in the structure of high boron iron-base alloy. When the melt was solidified in metal mould and sand mould respectively, the grain size of austenitic primary crystal decreases with the cooling rate increase. In addition, the morphology of borides was changed greatly. After heat treatment, borides of samples made of sand mould were changed little, otherwise, borides of samples made of metal mould were changed to granulation shape and the impact toughness was increased by 60%..

Effect of niobium on the microstructural and mechanical properties of as-cast Ti-48Al-0.7B cast alloy has been systematically studied in the paper. It has been found Ti-48Al-0.7B-5Nb alloy has the minimum grain size and the optimum balance mechanical properties.

Effect of boron on the microstructue and mechanical properties of as-cast Ti-46.5Al-8Nb alloy has been studied. It has been found that boron can refine TiAl grain size and coarsen interlamellar spacing. The interlamellar spacing () shows linearity relationship with grain size d-1/2. The Ultimate tensile strength (UTS) shows Hall-Petch dependences on grain size.

Al2O3 ceramic coating is prepared by plasma spraying and laser remelting on AZ91HP Mg alloy. The results show that the plasma-sprayed Al2O3 coating consists of -Al2O3 and -Al2O3 phases with the macrostructure of lamellar stacking. After laser remelting, the coating exhibited obvious layer characteristic due to influence of temperature distribution, thermophysical parameters and layer thickness. According to the microstructural difference, the coating can be divided into the melted zone composed of the -Al2O3 columnar crystal, the sintered zone with flocculent-structure characteristic, the residual plasma-sprayed layer with loosen structure, Al-Si transition layer and the substrate. Because of fine structure and high density, the hardness, wear and corrosion resistances of the laser remelted coating are much higher than those of the plasma-sprayed coating and as-received Mg alloy.

The fatigue life and cyclic deformation behavior of UFG copper produced by ECAP is studied in this paper. The changes of the grain size and the development of slip bands are observed by means of electron back scattering diffraction and TEM, respectively. The result shows that the fatigue limit of the UFG copper corresponding to 107 cycles is 153MPa. Cyclic softening occurs in the low-cycle fatigue region whereas stable cyclic behavior or even cyclic hardening occurs in the high-cycle region. Persistent slip bands (PSB)-like shear bands (SBs) were approximately parallel to the shearing plane of last pressing. The formation of SBs is the main factor causing crack nucleation as well as premature failure.

Based on the Miedema model and Tanaka equation, a new method for calculating the parameter of the Molecular Interaction Volume Model(MIVM) has been developed to get the activity coefficient of multi-component liquid alloys. The predicted activity coefficients of components in Ti-6Al-4V, Ti-5Al-2.5Sn and Zn-Sn-Pb-Cd-Bi alloys present a good agreement with the experimental data.

Uniform and transparent amorphous titanium dioxide films were prepared on glass by pulsed bias arc ion plating at room temperature. The influence of pulsed bias on the film optical property was investigated by varying the bias from 0V to 900V. The results show the as-deposited films are amorphous. The bias greatly affects film optical property. The deposition rate first increase and then decrease with increasing the bias, and the peak appears at 100V. As the bias increases, the film absorption edge shifts to the red side first, and then to the blue. While the band gap almost keeps constant, about 3.27eV. The film deposited at 300V reaches atomic smoothness, and RRMS is 0.113nm, which results in the highest refractive index, and nλ＝550 is 2.51, more or equal to the maximum value reported ever.

Thin film and granular tin electrodes as negative materials for lithium-ion batteries were prepared by electrodeposition onto copper foil collector. Their performances were studied with X-ray diffraction(XRD), scanning electron microscopy (SEM), cyclic voltammetry and charging-discharge experiments. The granular tin electrode and the film tin electrode can be prepared in fluoborate solution containing additives under stirred and unstirred condition, respectively. The thin film tin electrode shows its better discharge capacity and cyclic stability than the granular tin electrode: the discharge capacity of the film tin electrode is 787mAh/g for the first cycle and keeps 630 mAh/g after 40 cycles; but that of the granular tin electrode is only 576 mAh/g for the first cycle and keeps only 150mAh/g after 20 cycles.

The effects of a gradient high magnetic field on the morphology and distribution of the primary silicon grains in Al-18Si alloy have been investigated experimentally. It is shown that in the gradient high magnetic field the primary silicon phase grains, which are large plate-like or five-star-like in the case of solidification without magnetic field, are accumulated on the top of the specimen and refined remarkably with the morphology of polygonal or nodular shapes when the alloy solidifies from the semisolid state. In the segregated layer of the silicon, the distribution of the silicon grains is homogeneous. The size of the primary silicon grains decreases and the grain number density rises with the increase of the magnetic strength maintaining the magnetization force unchangeable. It seems that the high magnetic field influences the diffusion of silicon. Theoretical models have been proposed to explain the refining and the distribution of the silicon grains.

Cobalt ferrite nanoparticles were synthesized in high static magnetic field by coprecipitation-phase transform way, and the influences of magnetic flux density(MFD) on the shape and properties of cobalt ferrite nanoparticles was studied through SEM, X-ray diffraction and Vibrating Sample Magnetometer. It was shown that, when without magnetic field or MFD lower than 2Tesla, spheric cobalt ferrite nanoparticles was obtained, and when MFD was equal or above 4Tesla, claviform cobalt ferrite nanoparticles appeared. With the increase of MFD, much claviform cobalt ferrite nanoparticles was obtained, and the crystallization of cobalt ferrite nanoparticles became better, also the magnetic properties such as remanence magnetism, saturation magnetism and squareness ratio were increased remarkably. The remanence magnetism of cobalt ferrite nanoparticles prepared in 10Tesla magnetic field was 15 times to that without magnetic field, and saturation magnetism was elevated by 1.44 times. Based on the theory of magnetic aggregation and critical magnetic domain, the mechanism how the high static magnetic field affect the shape, crystallization degree and magnetic properties of cobalt ferrite nanoparticles by coprecipitation-phase transform way was discussed.

The formability of AZ31B magnesium alloy extruded tube was investigated by tension test and hydrobulging test. The result show that with the increase of temperature, the tension property along the extrusion direction increased significantly, while the maximum hydrobulging ratio did not change accordingly. The anisotropy induced by extrusion process is one of the main reasons for the difference of properties in axial direction and hoop direction. The extrusion weld line became the position where fracture will first occur, especially at elevated temperature. This acts as another important factor that decreases the formability of the extruded tube during hydrobulging.

According to Norton Creep Constitutive Equation and creep parameters of as-cast Ni-based BNi-2 filler and 0Cr18Ni9 stainless steel, 100 thousand hours creep analysis for Micro Plate-fin Heat Exchanger made of stainless steel was carried out by ABAQUS finite element code. The creep strain and stress distribution of overall Micro Plate-fin Structure was obtained. The creep deformation and the most dangerous position at high temperature were predicted. Due to the mismatch of mechanical property between brazing filler metal and base metal, the welding residual stress was generated inevitably during the brazing process, which has great influence on the creep deformation and life. Especially in the fillet, the creep strain and stress distribution is inhomogeneous and concentrated. In the interface, the stress and strain show discontinuous and uncoordinated, which have great effect on creep failure.

The Laser Rapid Forming (LRF), an advanced solid freedom fabrication technology, has a bright future in manufacturing of high performance dense metal components with complex structure in aero, spaceflight and many other fields. During LRF, the melting pool free surface serves as a moving window of laser power and powder mass input and a dynamic boundary of the LRF continuous growth domain, so the interaction between laser, powder and melting pool free surface is the basic problem that should be coped with in LRF process. In this paper, the melting pool transient temperature field and gas/powder two phase fluid field numerical model are established. Using finite element birth and death technology, the growth of cladding layers and shape of melting pool free surface are simulated, and using Lagrangian particle tracking model and momentum loss (parallel and perpendicular)option, the interaction between melting pool free surface and powder such as capture and reflect are simulated. At last, the interaction between 316L stainless steel powder, laser and melting pool free surface is calculated, and the numerical result is in agreement with that of the experiment.

During powder injection in the bottom-blown ladle, forces acting on particle were analyzed in consideration of the interaction between gas and particle. The motion equation of particle was established, and the relationship between the time of particle, moving distance and velocity was deduced. It shows that the velocity of little particle, after short time or distance acceleration, increases slowly.

Cu nano-particles and homogeneous Cu coating on Nocadia surface studied by microbiological method and surface analysis technology were prepared by electroless deposition method with appropriate surfactant. It was found that surfactant A was superior to some other kind surfactant under the same other conditions. Nocadia dispersed in pre-processes solutions and electroless plating solutions in the synergistic action of surfactant A and agitation. Cu particles with the size of 20nm deposited on Nocadia surface successfully and formed homogeneous Cu coating with the thickness of 200nm. Nocadia remained their original rod shape after Cu nano-particles deposition. Micro-rod metal material formed of Cu nano-particels was obtained.