Based on the Sieverts law and the thermodynamic model for activity coefficient prediction, a new thermodynamic model has been developed for calculating the hydrogen so- lubility in molten multicomponent alloys in which only the hydrogen solubilities in pure met- als are required. The predicted hydrogen solubilities in several molten aluminum alloys at different temperatures and compositions have a good agreement with the experimental results.

The microstructure, texture and phase transformation of forged bar, hot-extruded tube and cold-rolled tubes at different conditions of Ni47Ti44Nb9 alloy were investigated in terms by optical microscope，DSC and X-ray technique，in order to provide theoretical data for application of cold-rolled tubes in engineering. The results show that B2 phase presents broad fibred shape in the forged rod, and major textures are close to {112}〈111〉and {110}〈111〉; Fibred microstructure in hot-extruded tube becomes fine and fibres have broken, at the same time, {111} orientation of many grains is close to axis direction of tube; Microstructure in cold-rolled tube consists of B2,β -Nb and (Ti,Nb)4Ni2O phases, fibres has heavily broken, which restrains phase transformation during cooling and heating. And {111}<110〉and {112}〈110〉become the major texture components; As the result of the increase of heat treatment temperature, hardness decreases, temperature interval of phase transformation becomes narrow, transformation peak rises, the primary {111}〈110〉and {112}〈110〉textures markedly enhance. Recrystallization grains have grown at 850℃, thermal hysteresis and hardness obviously drop. The primary texture components depart from {111}〈110〉and {112}〈110〉.These are disadvantageous to expect to obtain greater mechanical properties and restoration strain along radial direction of tube.

A new process of the Solid Oxygen-ion Membrane(SOM) to produce Chromium directly from Cr2O3 has been proposed in this paper. Which was contrasted with the FFC process. Through SEM, EDX and XRD analysis the result showed that, when electrolyzed for a period 2 hours using SOM process, the Cr2O3 pellets were full reduced to Cr metal, oxygen content was not found in the Cr particles, with the current efficiency and current density being 83 pct and 0.72A/cm2, respectively. But using FFC process to electrolyze for 6 hours, only outside of the Cr2O3 pellets were reduced to Cr metal, the inside without reduction, with the current efficiency and current density being 22 pct and 0.31A/cm2, respectively. The changing law of current with time showed that the SOM process have many merits such as the faster electrolysis speed, higher current efficiency and current density, the aside reactions were not happened. So it has a promising future.

The solidification characteristics of rapidly solidified M3/2 high speed steel powers produced by water atomization were investigated. The cooling rate of the powers was calculated to be 10^5～10^7K/s. In the size range of the atomized powders, the microstructure was found to exhibit an equiaxed crystal morphology, with carbides existing in continuous network between the crystal grains. The matrix of the HSS powders was principally austenite; as the particle size decreased, the matrix changed from austenite to austenite/ ferrite. The types of carbides were mainly cubic MC and close-packed hexagonal, M2C.

The solidification process of Cu-80wt%Pb hypermonotectic alloys was investigated in four different experiment conditions. The formation process and structure of Cu-rich sphere phase has been analyzed, and the influence of high magnetic field and cooling rate have been considered. The results show that the morphology of spherical Cu-rich phases mainly has three kinds of microstructure, that is the larger “net-shell type” and the smaller “egg-type” or “eye-type”. The cooling rate of the samples has great effect on both macrostructure and microstructure. As the cooling rate become slow, the Cu-rich phase changed from the fine sphere to the larger floating sphere and the finally coarse dendrite, and the thickness of Cu-shell and reticulum of Cu-Pb in Cu-rich sphere phase became coarser; The 12T high magnetic fields have a remarkably effect of restraining the gravity segregation of Cu-Pb alloy by preventing from the floating of larger Cu-rich droplets and sedimentation of Pb-matrix, so that a macrostructure and microstructure of Cu-Pb monotectic alloy similar to one under relative fast cooling rate is formed. And the 12T high magnetic field maybe has the effect to inhibit the transition of Cu solute both outside and inside of Cu-rich sphere phase, which inhibit the Cu-rich shell from becoming thicker, and the Cu-Pb “net-like” phase from coarsening.

The effects of electromagnetic vibration with a strong magnetic field on the solidified structure of hypoeutectic Al-4.5%Cu alloy were experimentally studied. It was found that the morphology of was transferred from coarse dendrite to refined spheroid. At a constant magnetic flux density, the size of grains was decreased significantly with the increasing of current density. While at a constant current density, the refinement was increased firstly with the increasing of magnetic flux density and then diminished appreciably. X-ray diffraction indicated that the refining grains were oriented with <111> towards the magnetic field direction. The orientation degree was increased with the decreasing of grain size. The relation between orientation and grain size was analyzed from crystal orientation and migration theory.

High temperature proton conducotor CaZr0.9In0.1O3-α was prepared by direct synthesis method, and the average grain diameter of the powder was 1.88μm. Hot pressure casting method was used for preparing the tube, whose density was 97.44% relative to theoretical density. SEM fracture analysis showed the grain size was 1～3μm. EDS and XRF showed that the material had In elelment lost after sintered. This is because In2O3 sublimed and decomposed when temperature was higher than 1200℃. The conductivity of CaZr0.9In0.1O3-α was 0.91×10-4～1.21×10-2 S•cm-1 at the temperature range of 931～1300K in air. The value was a little small than the value in H2 and larger than the value of CaZr0.97In0.03O3-α in air in the literature. This was corresponded with theoretical conjecture.

In this article presented, the Particle Swarm Optimization (PSO) with inertia weight factor was applied for the quantitative texture analysis based on Maximum Entropy Method (MEM). Following this method, one has obtained fairly satisfying calculation results of complete orientation distribution for many samples of Deep-drawing Steel sheets and purity copper with macro orthogonal symmetry. In the processing data, there is not any assumption except the entropy is maximum. The samples compositions, texture components as well as their orientation distributions have no effect on the calculating results.

Fe-Si coating with high silicon content was prepared by laser cladding method on low silicon steel surface. Microstructure, hyperfine structure and structural transformation at RT of laser cladding coating were investigated by scanning electron microscopy, transmission electron microscopy,Mossbauer spectroscopy and X-ray diffraction. The results show that there forms metallurgical bonding at the interface between Fe-Si coating and substrate and there exist planar, columnar and dendritic microstructures from the interface to the top surface of the coating. In the laser cladding coating, six different atom configurations of Fe atom are observed. The primary phase containing Si atom is corresponding to the α-Fe type phase of disorderd solid solution structure whose relative content is 24.6 %. The isomer shift increases and the hyperfine magnetic field decreases as the number of nearest- neighbour Si atoms increases in the α-Fe type phase.

Ti and Al2O3 targets are used to prepare a series of TiN/AlON nanomultilayers in the gas mixture of Ar and N2 with reactive magnetron sputtering method. The formation conditions of AlON and the effects of thickness of AlON on microstructures and mechanical properties of the multilayers are evaluated and characterized by X-ray energy dispersive spectroscopy, X-ray diffraction, high resolution transmission electron microscopy and nanoindentation. The investigations show that O atom in Al2O3 will be partially replaced with N atom when sputtering Al2O3 target in the gas mixture of Ar and N2, forming amorphous AlON. In TiN/AlON nanomultilayers, when thickness of AlON is less than 0.6nm, AlON, due to the template effect of TiN crystal layer, is forced to crystallize and grow epitaxially with TiN, and the multilayers begin to show superhardness effect with a highest Hv value of 40.5GPa. With further increase of the thickness of AlON, its growth mode changes from crystal to amorphous, therefore destroying the epitaxial structure of multilayeres and leading to a decreased hardness of multilayers.

Porous NiTi shape memory alloy (SMA) with three-dimension connected pore structure and excellent biocompatibility owns the widely application as hard tissue implant. Affected by the special pore structure, nonequilibrium phases and internal stress induced by combustion synthesis process, the releasing rate of porous NiTi SMA in simulated body fluid and physiological saline is much higher than that of the dense NiTi SMA with same nominal surface area. The Ni releasing rate of porous NiTi SMA under bending strain will further increase. After immersion in 4M/L NaOH aqueous solution treatments for 24h and subsequent heating at 600℃ for 1h, a oxidation layer forms on the surface of the porous NiTi alloy. This layer prevents the porous NiTi alloy from the immersion solution and greatly decreases the amount of nickel release from the porous NiTi shape memory alloy.

The anticorrosion and inhibiting mechanism for the self-assembled monolayers(the SAMs) of 3-amino-1,2,4-triazole (ATA) on the surface of Cu-Ni alloy have been investigated by electrochemical method,as well as its adsorption behavior. The results indicate that ATA is liable to interact with Cu-Ni alloy as a result of formation of the SAMs on the surface of Cu-Ni alloy. The SAMs change the structure of the double-electric layer and make the potential of zero charge(PZC) shift in a positive direction.In addition, The SAMs restrain the process of anodic oxidation and have well anticorrosion effect .It is in good agreement with the results by EIS and polarization curve methods. The results from electrochemical measurements indicate that the corrosion resistance for Cu-Ni alloy electrode is improved by the ATA SAMs. Adsorption of the ATA SAMs is found to follow the Langmuir’s adsorption isotherm, and the adsorption mechanism is typical of chemisorption.

In order to study the SCC susceptibility of X70 pipeline steel in solutions which simulated the acid soil environment of Yingtan, China, slow strain rate testing (SSRT), microstructural observation of fracture areas by SEM and potentiodynamic polarization curves were used here. SCC did occur in the as-received material, with a transgranular cracking mode charged with different cathodic potential.The applied cathodic polarization potential played a important role in facilitating the occurrence of SCC.X70 pipeline steel was little sensitive to SCC in a athodic potential condition, but tended to be attacked by pits and uniform corrosion. However, as the applied cathodic potential droped, a combined electrochemical reaction of athode and cathode controlled the SCC behaviour of X70 steel, and as the applied cathodic potential droped further, cathodic reaction controlled SCC origination of X70 only. At the combined electrochemical condition, cracks occurred with pits together, which were more crowded than those at single cathodic condition at which cracks originated by themselves.

Developing high strength pipeline steels with good sulfide stress cracking (SSC) resistance is a hot topic of pipeline research. In this paper, the role of sulfur content on mechanical properties and SSC resistance of four pipeline steels, with different sulfur contents, i.e. 5, 17, 50,100 ppm respectively, was investigated; and the role of microstructure on these properties was discussed as well. The results showed that high sulfur content, more than 100 ppm, led to the formation of II type MnS inclusion and worsened fracture toughness, but it did not have bad influence on tensile properties and SSC resistance. Furthermore, coarsen carbonnitride, inclusion and even pearlite are potential hydrogen traps, but these are not the most important factors that influence SSC resistance of pipeline steel. Dislocations, especially motional dislocations without pinning effects of finely dispersed precipitates in acicular ferrite are hydrogen carrier and mainly transportation means of hydrogen, which results in the relatively poor SSC resistance of acicular ferrite microstructure.

The structural relaxation and glass-forming ability(GFA) of Mg-Cu-Gd-based glassy alloys and the effect of Ni addition on structural relaxation and mechanical properties were studied by thermal analysis, X-ray diffractometry (XRD) and transmission electron microscopy (TEM). The medium-range order(MRO) zones of about 1-2nm size were observed in the Mg65Cu25Gd10 glassy alloy after structural relaxation caused by annealing for 180s at 305K. Partial substitution of Cu by Ni in Mg-Cu-Gd-based alloys not only improved the mechanical properties, but also increased the stability against structural relaxation.

Al85Ni5Y8Co2 has the highest glass forming ability in Al-based amorphous alloys to date. To locate the optimum composition in its basic system is of great importance for preparing Al-based bulk metallic glass. Al-Co-Y system has not been studied thoroughly as yet. In this work, it is indicated that Al88Co5Y7 is the best alloy and its critical thickness is up to 230 μm. The glass forming ability shows a strong dependence on composition in this system. Surprisingly, there is no obvious glass transition phenomenon upon heating in the best glass formation alloy. Compared with Trg and ΔTx criteria, phase selection method is proved to be effective to locate the optimum alloy and characterize the glass forming ability dependence on composition in this system. It is fcc-Al, Al3Y and Al9Co2 that compete with amorphous phase during its formation.

Investigation of the local structure evolution and the glass formation in the Pd55Ni45 alloy melt rapidly cooled under high pressures is performed using molecular-dynamics simulations. The critical cooling rates for glass formation are reduced apparently with the pressure. With the increase of pressures, a more compacted local structure with more ideal icosahedra than defected icosahedra is obtained, which may possibly be one of the main factors for the contribution of the high pressure to the glass formation.

The bone tissue engineering scaffolds must possess good mechanical properties. Porous magnesium(Mg) metals have obvious advantages as a new class of bone tissue engineering scaffold. In this paper, the finite element method (FEM) was applied to systematically analyze the influences of porosity, pore size and pores arrangement on the compressive behavior of a new type of porous magnesium with straight pores fabricated by laser perforation technique. The distortion law of porous magnesium in the process of compression was also discussed. The results indicated that FEM can be an important way to the evaluation of mechanical behavior of this new class of porous magnesium metals and the application in bone tissue engineering.

A nucleation model based on the statistical analysis of a number of experimental data was developed and the related thermodynamics and kinetics parameters were presented for low pressure die casting of ZL114A alloy. A modified CA-FD method was proposed to simulate macro solidification process and microstructure evolution of the alloy. The preferential growth orientation, the solute redistribution in both liquid and solid, the solid/liquid interface curvature and the growth anisotropy were all considered in the model. The grain size, secondary dendrite arm spacing and eutectic content volume fraction of the alloy at different cooling rate were predicted and compared with experimental results of step-shaped sample casting.

A mathematical model was developed to calculate the 3D transient temperature, velocity distribution and the evolution of weld pool shapes in a stationary gas tungsten arc (GTA) weld pool on 304 stainless steels with different oxygen content. The results indicate that when the oxygen content increases, the convection pattern in the weld pool undergoes a dominant outward convection, outward on pool center together with inward on pool periphery, and a dominant inward convection. Accordingly, the weld pool evolves from a shallow wide shape, a spoon-like shape to a deep narrow one. The minor active-element oxygen in the weld pool influences on the temperature coefficient of the surface tension, directly, which leads to the significant change of the Marangoni convection pattern and hence the weld shape. When the oxygen content is below 80ppm, an outward Marangoni convection pattern on the weld pool surface occurs, and forms a shallow and wide weld shape. As the oxygen content exceeding 120ppm, the Marangoni convection changes to inward direction and the weld shape varies from a shallow and wide shape to a deep and narrow one. When the oxygen content is between 80ppm and 120ppm, the weld pool exhibits a spoon-like shape. And as time going, the outward convection region in the weld pool becomes smaller gradually, and the inward convection region becomes larger. The simulation results agree well with the experimental data under Ar-O2 mixed shielding stationary GTA welding on SUS304 plates.