The rotations of subgrains around particles in deformed matrices of different rolling orientations and their nucleation at the early stages of recrystallization were studied by means of electron back scattering diffraction (EBSD) technique in an SEM and were compared with those in single crystals of similar orientations. Results show that the subgrain rotations around particles within deformed matrices and the orientations of particle stimulated nucleation grains are not random, but singular to those in the similarly oriented single crystals. The second part of this work will deal with the interaction of particles with other nucleation sites (i.e. grain boundaries and cube bands) and the formation of recrystallization texture.

On the basis of analyzing the subgrain rotations around paricles within deformed matrices and their nucleation, a further investigation of the orientations of grains formed at particles locating at grain boundaries and cube bands was carried out and the formation of recrystallization texture was analyzed. Results reveal that the orientations of the grains at these places retain the orientational features of particle stimulated nucleation within deformed matrices and possess the characteristics of nucleation at grain boundaries or at cube bands. Recrystallization texture is produced by nucleation at different sites.

Microstructure and texture evolution of Ti-49.6Al-0.16Ni-0.14B alloy forged at 900℃ and then annealed at various temperatures were studied. Their texture components were accurately determined by the modified maximum entropy method (MMEM). Possible mechanisms of texture formation during deformation and annealing were proposed. A microstructure heredity characterization of deformed and annealed γ-TiAl alloy was reported.

In this paper, surface relief effects associated with grain boundary allotriomorph (GBA) in an Fe-0.37C (mass fraction,%) steel were investigated by scanning tunneling microscopy (STM) for the first time. It was discovered that GBA does produce surface reliefs. The surface reliefs originate only from the GBA, not from both the GBA and its slip accommodation which took place in the matrix. The GBA which exhibits the surface relief is only developed into one austenite grain, and the GBA in adjacent austenite does not produce surface relief effects. This means that the GBA/austenite interface is coherent or partially coherent, but the interface between the GBA and the adjacent austenite may be incoherent. The height of surfaCe reliefs is 157-352 nm, and the maximum shape deformation is 0.37. On the broad face of the GBA exist super ledges, whose height is 300 um. The configuration of edge-to- edge sympathetic nucleation is commonly observed in GBAs. All the experimental results indicate that GBA is formed by a sympathetic nucleation-ledgewise growth mechanism.

Molecular dynamics simulation has been performed to investigate martensite nucleation and growth at an edge dislocation dipole employing embedded atom method (EAM) type interatomic potential. The results indicate that the stress field of the dislocation dipole has important effect on the martensite nucleation and growth. The calculation of the stress distribution of the dislocation dipole shows that martensitic nucleation was preferentially initiated at the sites in the stress field where the stress state assists the lattice deformation of martensitic transformation. The two dislocations moved apart gradually, driven by transformation strain during the growing process of the martensite. The slip of the dislocation plays a role of plastic accommodation.

Dielectric function (DF) of metal cylinder with infinite length has been calculated using nonequilibrium statistical mechanics. The results show that the intrinsic DF of metal will be changed if the cylinder's surface is inelastic for electron scattering. As the radius of the cylinder decreases to the range of the electron mean free path (MFP), DF deviates from the bulk value and depends on the position in the cylinder gradually. The relation between DF and the position is complicated except when the radius is much smaller than MFP. Size effects may increase both real part ε' and imaginary part ε'' of DF and raise effectively the absolute ratio value of ε" to ε'.The radial distribution of oscillatory form of DF is discovered in the range of high frequence due to size effects.

Spherical particles of Ag-28.1Cu eutectic alloy with a wide range of diameters from 80 to 1000 μm were produced using a 3 m drop tube. It was revealed that a "lamellar eutectic → anomalous eutectic" transition occurred with decreasing drop diameter. The results of TMK model indicated that the maximum growth velocity, the minimum interlamellar spacing, and the largest undercooling of Ag-28.1Cu alloy for regular lamellar eutectic growth were 0.291 m/s, 0.017 μm and 193K respectively. A conspicuous grain refinement effect took place as droplet size decreased. The minimum measured eutectic interlamellar spacing was 0.092 μm, corresponding to a calculated eutectic growth velocity of 9.6 mm/s.

The Snoek-K- ster(SKK) damping in two bake hardening (BH) steels of 340 MPa class has been studied. It is found that the activation energies(H)of the middle-temperature peaks measured with a general range of frequency are obviously larger than that of SKK peak,and that there are double peaks in all the curves of Q-1- T of the steel containing 0.024%C which is one with higher content of carbon in both the steels, when the measurements were conducted with frequencies ＞1.7 Hz. The results were discussed in detail.

The structural characterization and intrinsic magnetic properties of the compounds SmFe10.7-x Mo1.3Gax have been investigated in great detail, which included the lattice parameters, Curie temperature TC, saturation magnetization σs, and magnetocrystallize　anisotropy. The results indicate that Ga occupies 8j and 8f sites, and substitution of Ga for Fe in SmFe10.7Mo1.3 leads to the expansion of the lattice constants a, c and unit cell volume V, the monotonical decrease of the Curie temperature TC, and the decrease of saturation magnetization and the Fe moments. The magnetocrystalline anisotropy changes from uniaxial to conical plane.

Based on the observations of slip patterns and saturation dislocation patterns,the cyclic stress-strain response was investigated by cyclically loading a copper bicrystal with a grain boundary perpendicular to the stress axis under constant plastic strain control. The results showed that the cyclic stress-strain (CSS) curve displayed a double plateau region in the plastic strain range of 1.80 × 10-4 － 2.56 × 10-3. The plateau saturation axial stresses were 62 - 64 MPa and 70 - 71 MPa respectively at axial plastic strain range of 1.80× 10-4－ 1.35× 10-3 and 2.04× 10-3 － 2.56× 10-3. The effects of component crystal orientation on the slip characteristics, saturation dislocation patterns and CSS curve were discussed.

analytical model for fatigue crack growth rate prediction is proposed based on the function of compressive residual stress on crack closure and the experimental results published in the literature. Using the proposed closure model, the crack growth rates of long crack, through-thickness short crack and surfaCe short craCk within a compressive residual stress field show fairly good agreement with the experimental results.

A new assembly with a long impact bar for measuring the dynamic fracture toughness K1d under the condition of fast fracture is described in this paper. The basic principle and the method evaluating K1d under the condition of the fracture time tf being less than the oscillation period of the specimen (τ) are given which include not only the impact velocity but also the impact load. An example is presented for measuring K1d of high strength armour steel 30MnCrNiMoB quenched and tempered at 200 - 600℃. The results show that Kid increases　with the loading time under high velocity impact, which are similar to those of 4340 AVR steel reported.

The tensile creep behaviors of DZ17G alloy, a directionally soliditied Ni-base superalloyl were investigated at 870 ℃ under the applied stress range of 330-420 MPa. All　of the creep curves have similar shape: a short primary creep and dominant accelerated creep stages. The creep apparent parameters (the stress exponent and the apparent activation energy for creep) and TEM observations suggest that the Orowan bowing process of dislocations is the dominant creep deformation mechanism. The reason why creep rate ascends at the beginning of accelerated creep stage is not the nucleation and propagation of creep cracks, but the consequence of microstructure change (γ' particles oriented coarsening uncompletely). The creep fracture data follow the Monkman-Grant relationship, and the final fracture process is controlled by the propagation rate of creep cracks.

Cyclic strain hardening and saturation behavior of double - slip - oriented single Crystals were investigated at constant plastic shear strain amplitude (γpl) in the range of 1.3×10-4－7.2×10-3. For γpl ＜ 2×10-3, the initial hardening rates θ0.2 are low and almost independent of γpl. For γpl＞ 2×10-3, θ0.2 increases notably with increasing γpl. The cyclic stress-strain (CSS) curve of crystal exhibits a clear plateau region over the plastic strain range of 5. 0 × 10 -4－4.0×10 -3, which is shorter than that of the single slip crystal (6.0×10-5－7.5× 10-3) although the saturation shear stresses are nearly the same. Even though the orientations of and crystals are on the same 001/111 boundary in the standard stereographic triangle, their cyclic deformation behaviors are quite different, such difference is mainly attributed to the rather different slip deformation characteristics induced by the different geometrical relationships between crystal orientations and corresponding slip systems for these two crystals.

A model without any adjustable parameters, describing the dependence of melting temperature on grain size, was established. It is demonstrated that melting temperature of metallic nanocrystals decreases as its size decreases. When the size of nanocrystals reaches its minimum, the melting temperature of the nanocrystals reaches its lowest value and the corresponding melting entropy is zero. With this model, the calculated melting temperatures of in and Pb nanocrystals and Fe thin film are in correspondence with the experimental results. The melting temperatures of magnetic recording nanocrystals of Fe, Co and Ni elements are predicted.

The measuring results for the viscosity of CaO--Na2B4O7 melts showed that the viscosity decreases from 0.759 to 0.033 Pa.s when the CaO contents Vary from 0 to 28.6mol%. The foaming behavior was investigated by means of injecting Ar and decomposing CaCO3 respectively. The foaming index Σ in the case of injecting Ar changes a little bit, but the values calculated with viscosity, density and surface tension have large deviation. With the average foaming life ,the foaming behavior of the melt in the decomposing CaCO3 could be described rationally, while in this case the foaming index Σ can not be applied to indicate the complicated measurement result.

The corrosion of two iron-based alloys containing 15% and 30% yttrium in H2-H2S mixtures under 10-3 Pa S2 at 600-800℃ was studied to establish whether yttrium　additions can improve the sulfidation resistance of pure Fe. the presence of yttrium is beneficial,but not as much as expected. In fact, the corrosion rate of iron is considerably reduced by the yttrium addition, but the two alloys were corroded still much more rapidly than pure yttrium. The sulfidation kinetics of pure yttrium are rather irregular, while the corrosion rate of pure iron and the two alloys tends to become parabolic after an hailal period of variable length. Under all conditions the two alloys form an external FeS layer, overlying an intermediate region of complex composion colltaining a mixture of the compounds of the two metals and an innermost region of internal attack. Thus, iron can still diffuse through the intermediate region to form the outer FeS layer with non-neglible rate. The scaling behavior of these alloys is discussed by taking into account the presence of intermetallic Fe-Y compounds and the limited solubility of yttrium in iron.

The observation of behavior of SCC of 321 austenitic stainless steel single crystal in boiling 42%MgCl2 showed that there was a relationship between the appearence of slip bands and the initiation or propagation of SCC. Although the stress corrosion cracks often nucleated at the intersection of two slip bands, they propagated along neither of these two slip bands. The SEM observations of the fractography of SCC showed that although the stress corrosion crack with river- markings or fan-patterns nucleated normally along the average macroscopic plane {100}, the detailed observations indicated that the microshear facets were along {111} plane.

C-V curves of copper electrodeposition on Pt(111) showed that there were two stages of underpotential and bulk deposition for copper electrodeposition process. Single layer growth at underpotential deposition and three dimensional nucleation growth at bulk deposition had been in situ observed by electrochemical scanning tunneling microscopy (ECSTM) at different potentials and times. The reflection electron microscopy (REM) images also revealed three dimensional growth of Cu deposition at high overpotential. All of these results demonstrated Stranski-Krastanov growth mechanism of copper on Pt(111).