The activities of Sb in nine Sn-Sb alloys at 923,1023 and 1123 K were determined by measurement of vapour pressure. By means of regression analysis, the relationship between the natural logarithm of activity coeifficient (lnγSb) and Sb content (XSb) of the alloys at the temperatures ranging from 923 to 1123 K was obtained, and the relationship between lnγSn and XSb also deduced according to Gibbs-Duhem equation. The results show that the nine Sn-Sb alloys at temperatures ranging from 923 to 1123 K are very close to the regular solution,and are also an actual solution with larger negative deviation from ideal solution.

The growing characteristic of cavities in Al-Li alloy during the superplastic plane strain and double axis tensile strain is investigated and compared.The experimental results show that the speed of cavity growing during plane strain are higher than that during double axis tensile strain. The cavities could be restrained by using a hydrostatic pressure. In later case, the restrain degree of cavity growing in plane strain is lower than that in double axis tensile strain. Therefore,the restrain of cavity growing during plane strain should be properly strengthened.

During the superplastic deformation of warm-rolled aluminium alloy 2214,the dislocation density in the grain remains equilibration to some extent because of the effect of dynamic recovery and recrystallization. The dominant deformation mechanism is grain-boundary sliding.The dislocation sliding in grain and diffusion creep, as two kinds of important coordination mechanism,promote the development of grain-boundary sliding.The superplastic deformation mechanism accords with the model of dislocation coordinating grain-boundary sliding.

The composition and crystal structure of the" White mud" ,or the Na-Al silicate slime in alumina production, is investigated by X-ray diffraction,IR spectra,differential thermal analysis, density detemination and chemical analysis concurrently. The chief phase, containing sodium aluminosilicate hydrate, has been identified to be hydroxy-sodalite crystals, usually having defect structure with vacancies of silicon atoms on the skeleton of sodalite lattice.

The cyclic voltemmetry, electrode potential-time curve after potentiostatic electrolysis, potential-step and X-ray diffraction methods were used to study the electrochemical reaction of Dy (Ⅲ) on Cu electrode in NaCl-KCl equimolar mixture. The Dy-Cu alloys formed first and then several intermetallic compounds of Dy-Cu containing more Dy formed in sequence. The metallic Dy depositsed at last. The standard free energies of formation for DyCu5, DyCu2 and DyCu are determined to be -107. 1,-101.9 and -75.6 kJ .mol(-1), at 1073 K, respeetively. The relationship between diffusion coefficient and temperature of Dy atom in DyCu5-DuCu2 alloy phase can be expressed as lnD = -67.1×103 / RT-15.8 and the diffusion activation energy is 67.1 kJ . mol-1. The production consisting of Dy-Cu alloy and Dy contains elemet Dy over 92%. The composition of alloy was DyCu and Dy.The current efficiency was near 80% .

Based on the macro-and mesco-experimental results of four steels ,30CrMnSiA,40CrNiMoA,No.45 and No.20,the random and fuzzy properties of fracture are studied.The isolated void model is used as an example,and the fracture occures as the void radius R is greater than the critical Rc. The void radius can be expressed as R=R0exp[C1exp(C2Rσ)εp](R0 is the initial void radius, Rσ the stress triaxiality,εp the plastic strain, C1and C2 are model parameters) .The initial and critical radii of voids are in lognormial distributions and the other parametrs in normal distributions. The calculated fracture characteristics of the four steels in different stress states and strains are more near to the experimental results taking the random fracture model than the deterministic fracture model.The illustrative calculation shows that fuzziness is the nature of fracture state,and with appropriate values the fuzzy model can agree well with the experimental results.

Starting from nonequilibrium statistical theory of fracture，the block diagram of micro－meso－macro multilevel connected theory of fracture is given.The role of all the different levels and their relationship in the fracture process are described．The transition from micro and meso structures into macro mechanical quantities is exhibited.

The TiN films were deposited onto low carbon steel substrate materials by hollow cathode discharge ion plating instrument under different substrate temperatures (150,250, 350 and 450℃),and the microhardness and wear resistance were measured.The results show that the values of HV of TiN films slightly increase but the varies of wear resistance can be neglected with change of the substrate temperature. Meanwhile,the textures of tin films were analysis by X-ray diffraction and their morphologies were also observed by scanning electron microscope(SEM).

Effects of concentration of flux solution,temperature of liquid aluminium,temperature of tools and pressure on shearing strength in solid-liquid pressure bonding of stainless steel and aluminium were investigated by means of artificial neural networks. The optimum bonding parameters were optimized with a genetic algorithm.

The residual stresses in 20% SiCp/6061Al (volume fraction)composite after aged and low temperature treatment were deteimined by means of X-ray stress measurement and finite element analysis. The measured and calculated results indicated that with the decrease in treated temperature, the average residual stresses in the matrix changed from tension to compression, and those in the reinforcement from compression to tension. By a suitable choice of the temperature for low temperature treatment,the average residual stresses in the matrix can be completely eliminated. However, the stress gradient and stress concentration still exist in the inner of composite after low temperature treatment.

Nano-Al2O3 powders processed by the hydrolysis technique of pure Al sheet after activation were added into Al2O3 ceramics.The results indicated that the nano-Al2O3 addition can increase not only the sinterability of the Al2O3 ceramics, but the fracture toughness and bending strength as well, and this kind of increase can be obtained only when the grain size of the added nano-Al2O3 is small enough, for example,37 nm.