Based on the empirical electron theory of solids and molecules, the analysison valence electron structure is made to Fe_3Al intermetallic compounds. The bonding com-plex model of DO_3 cell is set up. Some preliminary attempts at revealing the relationship be-tween alloy composition-structure-property and Fe_3Al alloy phase valence electron structureare presented.

The plasticity and toughness of as-cast high Al-Zn alloy may be obviouslyimproved by Ti modification. In the modified alloy, the heterogeneous nuclei, causing the re-finement of α'-phase, were observed to be ternary compound of single cubic Al_5Ti_2Zn withlattice parameter a=0.3959±0.0003 nm, not flaky or brocky Al_3Ti as generally expected.

An investigation was made of the eutectic microstructure during solidificationand the prespheroidization of eutectic carbide at elevated temperature of high speed steel M2inoculated with Mg. The traditional lamellar eutectic carbide M_2C in steel M2 may change in-to the fishbone eutectic carbide M_6C and block eutectic carbide MC if proper amount, saying0.012%, of Mg was added. The fishbone eutectic carbide prespheroidization may be retardedby Mg.

TEM observations were made of the precipitated particles in two high induc-tion grain-oriented silicon stfeels with and without Sn. The inhibiting ability of precipitatedparticles in the Sn bearing material for primary grain growth was compared with that in theSn free one.The temperature dependence of the primary grain size for the two materials wasstudied. A comparison of the total intensity of inhibitors was made between the twomaterials.Based on the above results, it can be concluded that Sn plays a role of an impor-tant inhibitor through segregation on primary grain boundaries.

The magneto acoustic emission (MAE) and Barkhausen noise (BN) of Co thatcontains 180 magnetic domain walls only were investigated. The magnetization curve andhysteresis loop of Co were measured. The magnetic domain pattern of Co was observed. TheMAE signals is evident before the appearance of "knee- on the magnetization curve. Thecharacteristic of the amplitude distribution of MAE of Co is the same as that of Fe-Si alloy.This means that the motion of 180° magnetic domain wall do contribute to MAE. The mod-el of the sources of MAE was discussed.

The bonding characteristic in Pd doping Ni_3Al was studied by DV-Xα clustermethod, and the mechanism for ductilization of Ni_3Al with Pd-doping was discussed basedon the theoretical model proposed by the authors. The ductilization is related with the in-crease of delocalized bonding electrons caused by Pd-doping. Since Pd-Al bond is strongerthan Pd-Ni bond, the delocalized bonding electrons will increase with the drop of Al content,this implies that hypo-stoichiomcrty in Al is necessary to the ductilization in Ni_3Al.

An aspect of the intermal fatigue limit for metals was proposed with the aid ofappraisal of the fatigue behaviour of shot peened, nitrided or carbonitrided steels. The inter-nal fatigue limit of metals seems to be 1.35 times of surface one. Based on this aspect, the fa-tigue strength of surface hardened steels was analysed.

The sdsorption behaviour of sodium oleate on quartz or feldspar has been ex-amined by zeta-potential and adsorbabilty measuremant, together with IR spectral analysesand flotation tests. Both electrostatic adsorption with oleate ions and physical one with oleatemolecules were occurred on quartz. While on feldspar, the chemical adsorption was con-ducted between oleate ions and Al. Thus, the adsorbability on feldspar is superior to that onquartz. The sodium cleate is able to activate feldspar flotation with amine as collector.

The equilibria of the system MoO_3-MoO_2-H_2O-H_2 were investigated usinga specially designed thermogravimetric apparatus under the control of atmospheres. The equi-librium constants for the reaction MoO_3+H_2=MoO_2+H_2O(g) were measured at P_(H_2O)/p_(H_2) ratio between 0.412 and 0.609 and in the temperature range of 400 to 534℃ as follows:lg(p_(H_2O)/ P_(H_2)=0.702-739.8/T.The standard enthalpy of formation and absoluteentropy forMoO_3 at 298.15 K have been evaluated as-854.75kJ/mole and 78.16 J/Kmole respectively. The experimental results show that the magneli phases in theMoO_3-MoO_2 system cannot exist as the thermodynamically stable phases under the condi-tions studied. The phase diagram of the system Mo-O between 400 and 700℃ has also beengiven.

Based on the ideal association solution model, the thermodynamic propertiesfor Ag-Ln(Ln=La,Ce,Gd) systems from 1300 to 1600K have been calculated. It is believedthat there exist AgLn and Ag_3Ln complexes (or associates)in the liquid phase. The short rangeordering is further discussed by using a concentration-concentration correlation functionscc(O).

The periodic and simple overloading behaviours of fatigue crack initiation inair and in 3.5% NaCl solution were experimentally studied and theoretically analyzed for300M (40CrMnSiNiMoV) steel. Retardation intensity of retardating crack initiation of corro-sion fatigue of simple overloading is significantly smaller than the corresponding value of pe-riodic overloading in 3.5% NaCl solution. The overloading retardation intensity increaseswith the increase of overloading ratio or level of equivalent stress amplitude value in air and in3.5% NaCl solution without exception. The physical essential resulting in the above-men-tioned results was also explored theoretically from several respects of residual stress, stress re-laxation and environment effect. If only the simple overloading retardation law is consideredin corrosion fatigue crack initiation life prediction, the very conservative life prediction wouldbe obtained. Only if the retardation laws of simple overloading and periodic overloading arecomprehensively considered, the comparatively higher precision life prediction can be ob-tained.

The corrosion behaviour of FeNiSiB amorphous alloys under different heattreatments has been studied by potentiodynamic polarization method and impedencemeasurement system. The dissolution activity of FeNiSiB amorphous alloys with differentcrystallization states is dependent upon the difference in their phase contents.

The crystallization behaviour of Al-La-Y-Ni quarternary amorphous alloys,prepared by single-roller melt spinning technique under vaccum, was studied by DSC thermalanalysis, X-ray diffraction and TEM. The crystallization behaviour was found to changewith alloy composition. Initial temperature of crystallization (T_(x1) increase with increasing ofREcontents. At the temperature higher than T_(x1), the tensile strength and ductility of alloyslost rapidly. Crystallization behaviour of Al_(88)La_(3.5)Y_(3.5)Ni_(3.5) alloy shows it is transformed by

In situ observation under TEM was carried out on the crystallization of prima-ry crystalline α(Fe, Si) in the sputtering Fe_(82)Si_6B_12 amorphous alloy film. The growth ofa(Fe,Si) is of dendritic morphology along <110> orientation. The nucleation of primarycrystalline a(Fe,Si) may be transient homogeneous, in circular or polygonal shape and to berapidly growing into dendrites. The growth of the α(Fe,Si) dendrites is controlled bylong-range diffusion of B atoms in the amorphous alloy. The self-diffusion coefficient of Batom in the sputtering Fe_(82)Si_6B_(12) amorphous alloy film together with the Arrhenius relationbetween diffusion coefficient and annealing temperature were obtained on the basis of kineticanalysis of its growing process.

A multi-functional gradient fiber coating was produced to meet the require-ments of liquid-fabrication, interface structure and properties of composites. The coating, in-cluding wettable,gradient and soft layers, was designed according to physical,chemical andmechanical mechanism, and has been fabricated with chemical vapour deposition. The desir-ous interfacestructure, profile of composition and wetting effect were achieved after applyingthe coating to C/Al composites fabricated by liquid-infiltration. The highest tensile strengthof samples is up to 1225 MPa, appproaching to the theoretical value. The influences of soft,gradient and wettable layers on the fracture mode and strangth of composites were studied,and the optimum thickness of each layer was gained experimentally.