The structure of molten DyF_3-BaF_2-LiF system has been simulated by Monte Carlo method. The radial distribution functions (RDFs), the local structure as well as the energy distribution have been obtained. The study indicates that F-ions distribute closely around Dy~(3+) ions and form mainly octahedral complex ions like DyF_6~(3-). There exist some "free" Li~+ ions in the molten system, they have the highest potential energy and are currentcarrying ions in the electrolytic conductance. F~-ions may be classified into three types: "terminal fluoride", "free fluoride", and "bridged fluoride", which have different behaviours. and their potential energies are also different. Some complex ions like DyF_m~(3-m) clusters are connected to one another by "flouride-bridge", forming more complicated ionic cluster like F_m-Dy-F-Dy-F_n or F_m-Dy< >Dy-F_n. As compared with molten DyF_3-LiF system.the octahedral complex ions like DyF_6~(3-) seems more close and more order than the binary system because of adding of BaF_2.

The behaviour of crack initiation of superpure stainless steel in 3.5% NaCl solution during low cycle corrosion fatiguing was studied by using three-electrode technique.The deformation may induce pitting at the passive potential which is less than the static pitting potential, but pitting was not found to initiate cracks. At low strain rate, the cracks were observed to initiate along the persistent slip bands(PSBs), and the electrochemical etching occurred at the PSBs. At high strain rate the cracks initiated at grain boundaries were obsereved. The results showed that the electrochemical dissolution accelerated the crack initiation process. and pitting at the localized deformed sites did not form the cracks at the passive system. And the strain rate affected the crack initiation mode.

The oxidation behaviour of Ni-11.82Al-1.03Zr-0.1B(wt-%) alloy with grain sizes of 30 μm and 180 μm was investigated at 900, 1100℃ in air. The short-circuit path for rapid diffusion along grain boundary is responsible for the change in the oxidation rate. At 900℃.with decreasing grain size.the oxidation rate of Ni-11.82Al-1.03Zr-0.1B alloy lowered; at 1100℃, grain size did not affect it. The structure and composition of the oxide scale were examined by EPMA and XRD analyses. which confirmed that the oxide layers formed on the two specimens are the same, containing NiO(outer), Al_2O_3, NiAl_2O_4(inner). The reactive element effect of Zr caused that the scale-alloy interface distinctly showed a different shape. a wavy interface(900℃) and a tree-like interface(1100℃).

The surface of pure Fe in which Ti~+-O~+ dual ions had been implanted was coloured by means of electrochemical method, with showing dark blue. light blue.brown. purple, gold yellow, as well as light colour, respectively.The coloured surface was analysed by X-ray photoemisson spectroscopy. The formation of TiO_2 and the enrichment of Ti in subsurface were found. It is confirmed that existence ot titanium oxide is neccessary to colouring. The shades of colour are decided by the concentration of Ti.

The microstructural feature of nanocrystalline Se (nc-Se) was investigated by using XRD and TEM. The lattice distortions were found from the quantitative XRD measurements, from which the dependence of the lattice distortions and cell volume changes on the grain sizes were obtained. and the bond lengths of the nc-Se were calculated as well. The experimental result of the lattice distortion in the nc-Se was explained in view of the crystallization micromechanism of random-coil chains folding.

The 1 kHz A.C.magnetic curves of Nd-xB_(20-x)Fe_(78)Cu_(0.3)Co_(1.7) amorphous alloys (x=0,1,2,3,4,5) melted spun ribbons specimens annealed at 430, 450,480 and 500℃ under vacuum for 0.5 or 1 h respectively were measured. With a minor Nd content the initial permeabilities of the amorphous alloys ribbons annealed near the crystallization temperature under vacuum decrease and the saturation magnetic fields increase. The materials may change from soft into hard magnetism and it is more remarkable with increasing of Nd content. Observations under X-ray or electron diffraction and TEM revealed that the nanocrystallites in size of 5-100 nm may precipitate in needle-shape and the more the Nd contains the more the quantity of them may be. These are in agreement with the results measured. Furthermore.a discussion was also made.

The RB-SiC/MoSi_2 composite was prepared by infiltration of Mo-Si melt, foaming MoSi_2 as a secondary phase, instead of residual Si in order to prevent the damage over 1400 ℃. Observations under SEM, TEM and HREM on the interface feature of the RB-SiC/MoSi_2 composite had shown that the uniform and continous network distributed along SiC grain boundaries. the thickness was about 5nm. The interface was composed of t-MoSi_2 and β-SiC, two-phase overlapped each other. Neither reaction layer nor amorphous matter was observed.

Amorphous carbon films with a smooth surface and a good adhesion to silicon and steel substrates have been prepared by ion beam assisted deposition (IBAD) using a single ion source. The energy of Ar ion ranged from 400 to 1500 eV. The structure and composition of the films were characterized using Raman spectroscopy, FTIR, HRTEM, TED. SEM, ERD and RBS. Electrical resistivity, microhardness and friction coefficient were tested to evaluate the films. The films was proved to be diamond like carbon (DLC). The hydrogen content measured by ERD is about 2.05 at.-%. The carbon hydrogen bond (C-H) seemes unformed. As ion energy and beam current increased. microhardness and friction coefficient increased. but electrical resistivity decreased. The increased microhardness is due to the increased film density and the decreased electrical resistivity is due to the decreased concentration of sp~3 bonds in the film.