An e/a-constant rule shows that the composition of the bulk metallic glass formers is always located in an e/a constant line or plane defined by the glass-related phases. Following this criteria, a series of alloys, with e/a (i.e. valence electron per atom) value of 1.2 and Ra (average atomic size) of 0.1474 nm, are designed in Ti-Zr-Ni-Cu system basing on an optimized quasicrystals-forming composition Ti40Zr40Ni20, then the alloy rods with diameter of 3mm are fabricated by the conventional suction casting method, the experimental results showed that a bulk glassy can be obtained in the vicinity of Ti12Zr55Ni13Cu20, and at the composition of Ti3Zr60Ni12Cu25 and Zr60Ni10Cu30, the another glass-related phase, tetragonal tI-Zr2Cu phase, is formed as the exclusive phase in the alloys. Electronic and atomic structural analysis revealed that the above quacrystals, bulk metallic glass and the tI-Zr2Cu phase are a group of electronic compounds sharing the nearly same e/a value, meanwhile, the local atomic structure of these phases are also correlative with each other, And a clearly e/a-constant phenomenon can be found in the compositional diagram, indicating that the e/a-constant criteria is valid for Ti-Zr-Ni-Cu glass forming system. Meanwhile, the structural correlations between the icosahedron and truncated octahedron clusters, which can be considered as an structural model to describe the polymorphous transformation from quacrystals or metallic glass to Zr2Cu-type phase，have been revealed in the present work.

Combining the One-Atom (OA) theory with Debye-Gruneisen model, adopting the lattice stability parameters determined by CALPHAD method, the temperature dependences of the atom states, atomic potentials and vibrating energies, atomic volumes, bulk moduli and linear thermal expansion coefficients of fcc- and metastable hcp- and bcc-Cu metals in SGTE database of pure elements have been studied, and the results show that the calculated electronic structure is accordant with that of first principles; the electronic structures of fcc-, hcp- and bcc-Cu are very close and the single bond radii of them are very close as well; the order of atomic volumes of them is Va(bcc)>Va(hcp)>Va(fcc), that of concentration of covalent electrons is nc(fcc)>nc (hcp)>nc(bcc), that of atomic potential energies is εp(fcc)<εp(hcp)<εp(bcc), and so the lattice stability is δG(fcc)>δG(hcp)>δG(bcc); the increasing amplitude of atomic vibrating energy is 2 to 3 times higher than that of potential energy during the elevation of temperature.

The growth kinetics of ferrite formed at intragranular inclusions and austenite grain boundaries in a low carbon microalloyed steel were analyzed by optical observation and theoretical calculation. The formation of intragranular ferrite on inclusions was later than that of ferrite allotriomorphs at austenite grain boundaries within the temperature range of 650-750℃. The undercooling for the formation of ferrite on inclusions is 40℃ larger than that at austenite grain boundaries. For the former the measured growth rate constant was smaller than that calculated, and for the latter the measured growth rate constant was larger than that calculated.

Morphological evolutions during the solidification of succinonitrite-5%water(atomic fraction) transparent alloy and Sn-15%Pb mass fraction) alloy under mechanical stirring were investigated experimentally by in situ observation and quenching, separately. The results showed that the primary solidified microstructures have a globular shape when the strong convection was induced by mechanical stirring. According to the morphological stability theory, the formation mechanism of globular microstructure was discussed. The analysis indicated that the rotation of primary microstructure in a shear flow induced a stabilizing effect on the morphological instability at the solid-liquid interface and promoted the globular growth of solidification microstructure.

A three-phase flow model has been developed to simulate globular equiaxed solidification based on the volume averaging and Eulerian- Eulerian methods. The three phases are liquid, solid and air respectively sharing a single pressure. The basic conservation equations of mass, momentum and enthalpy, and a user defined conservation equation of grain density have been solved for each phase. The thermal and mechanical (drag force) interactions among the phases have been considered. Grain nucleation, growth rate (mass exchange), solute partitioning at the liquid/solid interface and solute transport have also been accounted for. Due to the low density, the air phase floats always at the top region, forming a definable air/liquid melt interface, i.e. free surface. By tracking this free surface, the shrinkage cavity in an open casting system can be modeled. As the temperature and concentration dependent density and solidification shrinkage are explicitly included, the thermosolutal convection, together with feeding flow and grain movement can be taken into account. This paper focuses on the model description and the application examples will be introduced in the part II of this paper.

The developed three-phase model of equiaxed globular solidification has been applied for two examples: (1) cooling channel process of semi-solid slurry of A356 aluminum alloy; (2) equiaxed globular solidification process of Al-4%Cu. In the example (1), the effects of processing parameters on the grain density, size and solid fraction have been studied. The cooling channel semi-solid slurry preparation process has been reproduced. The results show that, the grain density has its maximum at the pouring position of the cooling channel, the grain size and solid fraction have their maximum at the end of the cooling channel. Their distributions are almost uniform in the mold after rheocasting process. Decreasing proper pouring temperature is helpful to increase the grain density and solid fraction, and to decrease the grain size. In the example (2), the roles that thermo-solutal convection and feeding flow acted in the solidification have been studied. Thermal convection and feeding flow dominate the flow pattern at the beginning of solidification, thermo-solutal convection plays the important role at the middle of solidification and the feeding flow controls the end of solidification. Additionally, the effects of grain movement and feeding flow on the formation of free surface and macrosegregation have been studied. The results show that, the obstacle of grain movement directly affects the shape of free surface, and completely different macrosegregation maps are obtained in case of considering feeding flow and without. The developed model has been validated by comparing the grain size between the measurement and simulation.

A phase-field model was built by optimizing characteristic parameters in the convectional phase-field model for peritectic transition, which is suitable to simulate microstructure evolution for peritectic transition of specific alloys. The growth of peritectic phase along the primary phase surface was simulated using this model for directionally solidified Ti-Al alloy at a high value of G/vp. The simulating results show that the difference of extending character of trijunction will cause two typical microstructures of discrete band and island band. Furthermore, the width of computational domain, the nucleation undercooling of peritectic phase and initial composition affect the extension of trijunction of directionally solidified peritectic alloy directly, and also the final microstructure.

The microstructure evolution of both phases is simulated by the phase-field model of peritectic transition for directionally solidified Ti-Al alloy at a high value of G/vP when the continuous nucleation occured to a sample with a small diameter and the multiple nucleation occured to a sample with a big diameter. The simulated results show that for the small sample decreasing sample size or nucleation undercooling of peritectic phase tended to form island band structure. But to the big sample, the differences of the volume fraction of peritectic phase and the nucleation rate cause to form the discrete band, island band and coupled-growth ructures

A systematic statistical analysis of the characteristics of the Portevin-Le Chartelier (PLC) effect in Al-4%Cu alloy, including the stress drop amplitude and the reloading time, etc., is carried out. The drop duration is found to be a constant independent of the strain. The average stress drop amplitude and the average reloading time of 1 and 2 mm thick samples increase with strain linearly, while the cases of 3 mm thick samples are much more complicated. The evidence of self--organized criticality is demonstrated, and the nonlinear mechanism in the PLC effect is also explained by comparing with the classic sand--pile model, and by combining with the dynamic strain aging (DSA) principle and the dislocation dynamics.

A series of white light speckle patterns was continually recorded by high-speed CCD (1000 fps) during the formation of type B serrated yielding (PLC) shear band in tensile tests of Al-4%Cu alloy. With the image analysis technology of digital speckle correlation method, the displacement and strain spatial distribution of PLC shear band were quantitatively obtained, and the evolution process of PLC shear band with time was reproduced. The results clearly prove an evolution mechanism of type B PLC shear bands, that is, a PLC shear band first nucleates at one side of specimen, then transversely runs through the entire specimen section with a certain angle, finally forms an inhomogeneous deformation bands. The experimental results show that there exists elastic shrinkage deformation outside the band during the formation of PLC shear band.

The Fe containing phase in hypereutectic Al-2.89%Fe alloy was accumulated towards the sample center under the alternating magnetic field, which is due to a large compression force orientated the sample axis acted on Al3Fe phases with a large magnetic susceptibility than melt aluminium. X-ray diffraction results showed that there was only Al3Fe phase existing in the Fe containing phases, whether solidified with or without the AC magnetic field. The alternating magnetic field can affect the distribution of the Fe containing phase instead of their type.

The hot deformation behavior of Ni76Cr19AlTi alloy was studied by compression test of cylindrical specimen at constant temperature and constant strain rate in a Gleeble-1500 system. The deformation temperature ranges from 800 ℃ to 1150 ℃, strain rate from 10 -3 s -1 to 1 s -1. The results show that Ni76Cr19AlTi alloy has a large deformed resistance and is easily fractured when deformed at 800℃ and 850℃. But when compressing at a temperature range of 950--1150℃, the resistance to deformation reduces and the alloy doesn't fracture because of dynamic crystallization. The measurement of the flow stress of the alloy in high temperature range of 950-1150 ℃ showed that the thermal deformation activation energy Q is 376.84 kJ/mol and stress exponent n is 4.15. By analyzing the true stress-strain curves for the alloy at hot compression and its deformation mechanism, the suitable deformation condition is at the temperature range from 1050 ℃ to 1150 ℃ with strain rate from 10 -1 s -1 to 10 0 s -1.

Mode II dynamic fracture toughnesses K IId for high strength steels, 40Cr and 30CrMnSiNi2A, subjected to impact loading were measured using an experiment-number combined method. The tests were performed on shear specimens with Hopkinson pressure bar and the time of crack initiation was determined by strain gauge. With 3-D transient finite element analysis, the time evolution of dynamic stress intensity factor under different loading rates was obtained and the dynamic fracture toughness was determined by fracture initiation time. The results show that within the loading rate range (2×10 6 -7×10 6 MPa m 1/2/s), almost all the specimens failed by adiabatic shear bands and the K IId values of the two steels increase with increasing loading rate. The K IId value of 30CrMnSiNi2A is larger than that of 40Cr at the same loading rate. The effect of ligament size on fracture toughness was also discussed.

The hydrogen storage properties and crystal structures of Ti 1+x Cr 1.2 Mn 0.8 (x=0.0, 0.1, 0.2, 0.3) and Ti 1+x Cr 1.2 Mn 0.8-y M y (M=Fe, Ni, Cu, V, VFe; x=0.0, 0.1; y=0.1, 0.3) have been studied systematically. XRD patterns proved that the two series of hydrogen storage alloys have the same crystal structure, C14(MgZn 2) typed Laves phase, which is suitable for hydrogen absorption and desorption with great amount. The lattice parameter a, c and cell volume V increase with increasing Ti content and substitution of Mn by Fe, Ni, Cu, V and VFe, while the hysteresis factors of P-C-T curves decrease. In order to develop hydrogen storage alloys for the metal hydride hydrogen compressor (MHHC), the effect of the substitution elements have been investigated, and the results show that both alloys, TiCr 1.2 Mn 0.5 Fe 0.3 and Ti 1.1 Cr 1.2 Mn 0.5 Cu 0.3 , have high hydrogen storage capacities and high compression ratios.

Microstructure and thermal fatigue behavior of Pb-free solder interconnects in ceramic ball grid array (BGA) packages were examined by cross-sectional microscopy, thermal cycling experiments and finite element modeling. The BGA assemblies were made by reflow soldering Sn-Ag-Cu solder balls between Ag-metallized multilayer ceramic chip and Cu-metallized printed circuit board using the eutectic Sn-Ag-Cu solder paste. In the as-reflowed condition, Cu6Sn5 and Ag3Sn intermetallic compounds (IMCs) were formed at the solder interfaces with Cu and Ag metallizations respectively. Following thermal cycling, the Cu6Sn5 layer grew thicker and Cu3Sn IMC was found at the interface with Cu metallization. On the ceramic side, visible thickening of the Ag3Sn layer was also observed. The Ag3Sn in the solder near the interface went through a morphological change from the needle shape to spherical. As a result of repeated thermal cycling, fatigue cracks developed in the solder interconnects. The fatigue crack appeared first at the corner of the solder ball with the chip, where the maximum shear stress was found by the finite element analysis. Subsequent growth of the fatigue cracks led to final fracture of the solder interconnects. The cracks preferred to propagate along the Cu6Sn5/solder interface on the side of the print circuit board and in the solder joint near the interfacial Ag3Sn layer on the ceramic side.

In AOD (argon and oxygen decarburization) converter, an important reactor for stainless steelmaking, the flow has a great effect on the refining process. Based on analysis of the behavior of a gas jet injected horizontally into liquid from side wall, a mathematical model was developed to predict the 3D turbulent flow in AOD, and the effects of gas flow rate and arrangement of lances on flow were investigated. The results show that the gas flow rate has a great effect on the trajectory of jet and flow of molten steel in the furnace, and the flow field and the distribution of turbulent kinetic energy become more reasonable in the bath with multi-lance injection. The predicted results were compared with the observation in water model, which showed a good agreement.

The effects of treatment time, lift gas flow rate and liquid height in vacuum vessel on inclusion removal in RH degasser were investigated by choosing emulsion drops simulated as inclusions in a water model. The results show that most of the inclusions can be removed after treatment for 12 min, and all the inclusions which can be removed almost disappeared from the system after treatment for 24 min. Larger lift gas flow rates seemed to be more efficient for inclusions removal and there is a lift gas flow rate for the best of inclusions removal (20 L/min for this work). The liquid height in vacuum vessel has also an optimized value for inclusions removal (46 mm for this work).

A series of Ti-based multilayered films were deposited using a new mid-frequency dual-magnetron sputtering system. The influences of Ti buffer layer on the film hardness and adhesion were investigated. The forming mechanism of macro-particles and caves was analyzed, and then the orthogonal design and variance analysis were used to discuss the influences of the target currents, the pressures of working gases and the substrate bias voltages on the densities of the surface defects, and the process parameters were optimized accordingly. The results show that the target current has the most important influence on the defect density, and the effects of the pressures and the substrate bias voltages decrease in turn; in the condition of the target current of 20 A, the gases pressure of 0.31 Pa, the bias voltages in a range of -160 - -300 V and the thickness of Ti buffer layers, x=0.12 um, the high-quality TiN/Ti multilayer film is obtained, whose Vickers microhardness HV 0.2 N is 2250, film-substrate adhesion (critical load L c) is 48 N, and surface defect density is 58 mm -2.

Cu-In films with chemical composition ratio of 1∶1 are deposited on stainless steel and Mo-coated glass substrate under constant current with Ti worked as anode. The Cu-In precursor film with the thickness of 1 um is uniform and compact. The influences of deposition parameters such as the electrolyte contents, current density, the type and concentration of complexing agent, $etc.$, on films composition and morphology were studied. Those parameters with the exception of current density are allowed to be same when different kinds of substrates are employed. Current plays an important role in affecting the property of precursor films. If the ratio of Cu 2+ to In 3+ is constant, the total concentration of ions showed inappreciable influence on film morphology. The result shows that lauryl sodium sulfate and sodium benzenesulfinate as ideal additives can make the films more flat and smooth. The Cu-In films prepared by such method provide a good foundation for further selenization process obtaining CuInSe 2 film.