Recent experiments indicate that stresses induced by atomic interdiffusion in solids can not only result in the macro-distortion of materials, but also form some peculiar micro-structures in the materials. Considered that little has been known in a detailed way of the mechanisms of diffusion-induced stresses, the relationship of atomic diffusion and stresses in solids will be elucidated and the concepts of creep-induced diffusion and diffusion-induced stresses are clarified in this paper. Based on the volume growth rate of a flow point, an equation is obtained for the relationship of stresses of flow point and atomic diffusion fluxes and therefore a general theory is constructed to describe the phenomena of diffusion-induced stresses and strains, e.g. the bending of thin diffusion couples and the periodic layer formation during solid state reactions.

In this study ,irradiation damage characteristic of carbide in Long term aging treatment for Fe-Cr-Mn alloy is investigated by electron beam and dual-beam with electron–hilum ion irradiation. The results indicate that the voids were observed inside carbide and along interface of carbide/matrix. Interface migration and interface segregation of Cr. Mn. W. V is first observed. The phase stability and reason of the irradiation damage of aged carbide are discussed with the interaction between point defects and solute elements and radiation-induced synergistic effect of hilum. The radiation damage phase is a form of expression of the unstability of phase.

Based on the microelasticity theory of coherent strain and the microscopic phase-field dynamic model, the morphology evolution and the coarsening behavior of Ni75AlxV25-x alloy during precipitation was simulated. The precipitates particles have the obvious orientation for the two phases when the coarsening happened. The [100] directions of phases are the preference orientation during the growth, and aligned along the <001> directions. The growth and coarsening of the first precipitates have two evident stage，but growth and coarsening of the last precipitates are proceeding simultaneously. The growth and coarsening of precipitates are take place by means of the coalescence between neighboring particles. In despite of the precipitation order and the volume fraction are different for different concentration, the morphology of two phases is almost same at last, which has the quadrate shape, and the orientation relationship of (001) //{100} is exist between two phases.

Adiabatic shear bands (ASBs) were studied by SEM electron channeling contrast (ECC) technique in fatigued copper single crystals with different orientations under high velocity impact using split-Hopkinson pressure bar (SHPB). The experimental results show that the critical strain of ASBs’ formation is orientation-dependent. Single crystal close to the compression critical double slip orientation needs less strain for ASB formation than the one with typically single slip and the one close to compression conjugate double slip orientations do. Single crystal close to the coplanar double slip orientation needs the maximum critical strain. Under current experimental circumstance the typical dislocation pattern within ASBs is dislocation cell structure, and no recrystallization was observed. There are three types of ASBs according to their orientations. The first type is that the plane of ASB is very close to the habit plane of the second type deformation band (DBII) in fatigued copper single crystals, which needs the minimum critical strain to form. The second type is rather close to the habit plane of either DBI (the first type deformation band) or DBII, which needs modest critical strain。The third type is neither close to the habit plane of DBI nor DBII, which needs the maximum critical stain.

Very high cycle fatigue behaviors of 54SiCrV6 and 54SiCr6 clear high strength spring steels and the fractography observed by means of field emission scanning electron microscope (FESEM) and electron probe microanalyzer (EPMA) are investigated. Experimental results show that for two steels, fatigue failure originates from sample surface matrix at high stress amplitude and from sample interior at low stress amplitude. The S-N curve of 54SiCrV6 spring steel is a typical step-wise curve, and elimination of fatigue limit in 109 cycles regime, however, fatigue limit of 54SiCr6 steel exists. Analysis of fractography shows that internal failure initiates clusters of little inclusions in 54SiCrV6 steel and localized carbide in 54SiCr6 steel. Evaluation of critical inclusion size shows that, in 109 cycles regime, fatigue limit eliminates when inclusion size is greater than critical inclusion size in high strength steel. Contrary, fatigue limit exists.

A new mathematical model and a parameter for the hardenability of steels is presented in this paper. A differential equation of the Jominy curves has been constructed according to the Jominy experimental data and change of derivative of the Jominy curve. The linear trial method was used to choose optimal type of function. The model for calculating the hardness distributions has been described as the subsection functions consisting of both straight line and curve. The straight depicts the hardness of the martensite region where the martensite is entirely obtained and the hardness remains a constant maximum value. In addition, the hardness is continuously reduced in the region of the curve until the hardness approaches a minimum value. The hardenability of steels has been expressed as a coefficient that is equal to the whole distance of inflexion of Jominy curve in numerical value. The distance includes length of straight line in which martensite is entirely obtained, while it is not related to the Jominy distance. The value of the hardenability has been obtained by a method of the non-linear curve fitting to the Jominy test data. Very good agreements have been obtained between the simulated curves and the experimental measurements.

Forming process of flaking in a wheel steel has been investigated. The cracking surface of the flacking is got using a special method, and is compared to various fracture surfaces of samples containing flaking. The results show that a cavity with H2, i.e. hydrogen blistering, forms and grows firstly, then microcracks initiate from the wall of the blistering, grow and connect each other resulting in formation of flaking. The cracking surface of flaking is a different idea with fracture surface of the sample containing flaking. The former is quasi-cleavage, similar to that of hydrogen-induced delayed cracking, but the later is dependent upon the failure method and the thickness of the sample. There is no effect of flaking in the steel on various fracture surface morphologies besides secondary cracks. Hydrogen-induced delayed failure is due to atomic hydrogen instead of flaking.

Based on the concept of iron-flow diagram of steel production process, a relational expression between iron resource efficiency of steel production process and of its unit process has been derived. By using the data of a steel plant, the relationship between iron resource efficiency of steel production process and of its unit process was analyzed, and the influence of iron resource efficiency of unit process on iron resource efficiency of steel production process was discussed as examples.

Tantalum was prepared by electro-deoxidation in a CaCl2-NaCl melt at 800℃. Ta2O5 powders were compacted in to pellets and sintered, and then conducted as a cathode, while a high-density graphite rod as an anode. It was investigated that the porosity and micro-morphology of the sintered Ta2O5 cathode affected the rate of the electro-chemical reduction and the purity of the product. The results showed that high porosity can increase the rate and extent of electro-deoxidation. The diffusion seemed to play an important role in the reduction process.

A novel electrodeposited Cu-rich Cu-30Ni-20Cr nanocomposite was fabricated on pure copper substrate by co-electrodeposition of Cu-Ni alloy base (mean grain size: 60 nm) with Cr nanoparticles (meansize: 28 nm) from a sodium citrate bath. Compared with electroplated Cu-40Ni alloy film prepared using the same bath, the Cu-30Ni-20Cr nanocomposite exhibited an extremely low oxidation rate in air at 800oC, due to the fast formation of a continuous Cr2O3 scale. The effect of the Cr nanoparticles on the oxidation behavior of the Cu-Ni-Cr nanocomposite films is discussed in detail.

Two types of protective silane films, bis-1, 2-[triethoxysilyl] ethane (BTSE) and Dodecyltrimethoxysilane (DTMS), were deposited on LY12 aluminum alloys with the aiding of electrochemical technique. Electrochemical impedance spectroscopy (EIS) tests shows that after silanization the corrosion resistances of Al alloys are increased significantly, especially after deposition at cathodic potentials. A critical potential (CP), namely -0.8V, is generally found for each silane system, prepared at which the highest protectiveness is obtained. Scanning electron microscopy (SEM) shows that silane films prepared at CP display the highest uniformity and density. Applying potentials more positive does not facilitate the film formation. On the other hand, when potential shifts more negative the surface of films presents porous morphology, probably due to the intensive evolving of hydrogen bubbling near the surface. Due to the presence of long hydrophobic Dodecyl chain in bone structure, DTMS films display the best barrier properties.

The corrosion and electrochemical behavior of 316L stainless steel in acetic acid solutions at 85℃ has been investigated. Acetic acid concentration tested was 60% and included addition of 0.2% KCl. Of key interest was the trends of corrosion potential on initial period. Corrosion potential–time measurements were undertaken after the samples exposed to the air for 24 h were polarized anodically and cathodically in acetic acid solution. With analyzing of the curves of electrochemical polarization and SEM and EDS data of the samples ,corrosion and electrochemical behavior and mechanism of localized corrosion of 316L stainless steel in acetic acid solution with Cl- were discussed. The results show that the samples exposed to the air previously for 24 h can be passivated automatically in acetic acid solution with Cl- with the corrosion potential remaining 100mV(SCE).No such phenomenon was observed for samples which were cathodically polarized with the corrosion potential stabilizing at a value of -242±3mv. The passive film formed by anodically polarizing is more proof than formed in the air.

A wedge-shaped crevice cell used to model previously disbonded coating holiday of X70 pipeline steel under impressed current cathodic protection in simulated solution of desert soil of Ku’erle in Xinjiang. Distributions of polarization potentials and current along long direction of the wedge-shaped crevice were measured in different time intervals at different opening control potentials (-850mV, -1000mV and -1150mV vs CSE) and at different crevice opening thickness (0.15mm, 0.30mm and 0.45mm). The influences of applied control potentials and crevice thickness on polarization potentials, polarization current and pH value in crevice were investigated deeply. It was showed that gradients of polarization potential and current in crevice gradually decreased with times, due to the depletion of dissolved oxygen. It was found again that, a negative shift of opening control potentials, and increase of crevice opening thickness resulted in the decrease of polarization potentials, and the increase of polarization current in crevice. On the other hand, the pH value in crevice gradually increased also with more negative opening control potential, and with increase of the opening thickness. At the same control potential, the pH value from crevice opening to bottom increased first, then stabilized at a definite value. Moreover, more negative shift of the control potentials and bigger crevice opening thickness can make the stable pH value increase, but the increasing rate gradually decreased.

With considering the characteristics of keyhole plasma arc welding and the plasma’s “digging” action to the weld pool, a new welding heat source model (TPAW) is proposed to describe and reflect the “reversed bugle” configuration of weld cross section under plasma’s action and the heat intensity distribution along the workpiece thickness direction. Based on TPAW, finite element calculation of temperature field in keyhole plasma arc welding is conducted, and the transient development of weld pool and surrounding thermal profiles are analyzed. The predicted weld geometry and the time needed to reach the quasi-steady state are in agreement with experimental measurements.

Numerical simulation of electromagnetic field and force field during electromagnetic continuous casting in hollow billets was carried out by ANSYS software in the paper. The simulation results show that the magnetic flux density is strong and distribution is even in tube ingot in out-phase electromagnetic field; Metal melt in the central section of the wall flows outer mold due to the electromagnetic force; Metal melt and initial skull near graphite were pushed by the electromagnetic force, which can avoid “hold core”, decrease friction, restrain segregation burl, and increase surface quality.

Nanocrystalline flakes of FeSiAlCr were synthesized by atomization process and high energy ball milling. Effect of process conditions on microstructure, morphology and microwave electromagnetic characteristics of FeSiAlCr particles were investigated. Results show that flaky morphology and nanocrystalline microstructure were gained by process of high energy ball milling. Thus, microwave permeability were improved remarkably and permittivity were controlled effectively. Effect of sequent annealing was also discussed and it was found that microwave electromagnetic performances were improved further. Microwave absorbing ability of coating layer made of the nanocrystalline FeSiAlCr flakes proved that the materials can be applied in suppression of electromagnetic interference or microwave absorption.

SiC/Al co-continuous composites were fabricated by squeeze casting method, and the effect of SiC foam and process parameters on their solidification, the mechanism of solidification were investigated. The results show the process parameters play important roles in the solidification of composites. The microstructure of composites fabricated by positive squeeze is more uniform than that of composites made by inverse squeeze. The grain of composites is becoming smaller with the increase of squeeze casting pressure, but the change is not obvious. And the grains of composites is also bigger with the enhance of preheat temperature of SiC foam reinforcement. The size of grain is not obviously change, but the morphology of grain is different when the reinforcement is joined into the matrix alloy. The column dendrite that is perpendicular to the strut of SiC foam is easily got when the aperture of reinforcement is smaller. When SiC／Al composites start to solidify, the primary column dendrite α－Al is gotten near the strut of SiC foam, firstly. Then column dendrite α－Al is present after α－Al is growing into the central of aperture. At last, the eutectic silicon appears at the central of aperture where different column dendrite α－Al gathers before the eutectic reaction occurs at the surface of strut.

An as-cast in situ Zr56.2Ti13.8Nb5.0Cu6.9Ni5.6Be12.5 bulk metallic glass composite with enhanced plasticity was prepared by water quenching, which contains a ductile bcc β-Zr solid solution. The β phase with a volume fraction of about 30% possesses a developed dendritic morphology. The present composite exhibits a pure plastic strain of 10.2% combined with a large elastic strain limit of 2% and a high ultimate strength of 1778MPa upon room-temperature compression. Microscopic observation shows numbers of wavelike shear bands dispersed on the surface of deformed compressive samples