The parameters of the thermodynamic model for the ternary system Ga-In-As are optimized from the available experimental data,and the influence of the elastic energy on the phase diagram,induced by the dismatch of the growing lattice with the substrate,is quantified.Correspondent:SHEN Jianyun,Laboratory No.301,(General Reserach Intitute for Non-Ferrous Metals,Beijins 100088)

The discrete complex anion modle was introduced to the molten salt solutions of LiF-CaF2,NaF-CaF2-and KF-CaF2,based upon the assumption of existence of the CaF3 complex ions contained in the melts.A set of parameters were evaluated from experimental data about enthalpies of mixing and phase diagrams of the above three systems.The thermodynamic properties and phase diagrams of the melts were calculated by using the model.The results obtained were in good agreement with experimental data.Correspondent:XU Qian,(Department of Nonferrous Metallurgy,Northeastern University,Shenyang 110006)

The Molecular dynamics simulation of molten MgCl2,with inter-ionic potential including polarizatoin term,has been performed. The partial RDFS calculated are in agreement with the experimental data obtained by neutron diffraction.The simulation results show that there are some irregular holes and complex ions in molten MgCl2.The number of CL-ions surrounding Mg2+ ions ranges from 2 to 6.Correspondent:CHEN Nianyi,professor,Shanghai(Institute of Metallurgy,Chinese Academy of Sciences,Shanghai 200050)

A modified pin-on-ring corrosive wear device was employed to examine corrosive wear behaviour of duplex stainless steel(DSS) annealed at different temperatures in 10%H2SO4.It is found that the corrosive wear resistance of the DSS annealed at high temperature is better than that annealed at low temperature under low load, but it is quite the contrary under high load.The same relationship between corrosive wear rate and load is found under cathodic protection(-600 mV,SCE).The morphology of wear tracks was observed by SEM,and the observation indicates that the poor corrosive wear resistance of DSS annealed at high temperature is due to embrittlement of large amount of ferritic phase.The influence of annealing temperature on hardness and corrosion resistance were also discussed.Correspondent:LU Xinchun,(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110015)

The repassivation potential for crevice corrosion(ER) of commercially pure Al was measured successfully using the method developed for stainless steels.The ER is a characteristic value depending on the geometry of the crevice configuration.The ER coincides with that lower limit of critical potential VCREV for crevice corrosion.The results showed that ER of commercially pure Al was less noble than the pitting potential by 100 mV,confirming that crevice corrosion is the more easily occurring type even in commercially pure Al.Correspondent:LIANG Chenghao,associate professor,(Dalian University of Technology,Dalian 116012)

Implantation of 2×1016,5×1016,1×1017Ce+/cm2 into Ni20Cr alloy can significantly decrease the oxidation rate at 1000 and 1100℃,and improve the adhesion of oxide scales.The changes of binding energy of alloy in elements in alloy surface after Ce implanting and in oxide scale formed at 1100℃ were measured using ion microperobe mass analyzer.The decrement of binding energy of Cr+on the alloy surface accelerate rapidly the formation of protective Cr2O3,however these of Cr+and Ni+ in the oxide scale increase,the outward diffusion of Cr3+and Ni2+through the scale are delayed.This seems to be the main reason for Ce implantation to decrease the oxidation rate of Ni20Cr at 1100℃.The oxide scales of Ce-implanted Ni20Cr alloy are dense,intact and well adhesive with the alloy.The oxide scales spall partially after 270 time during the cyclic oxidation at 1000℃,but the effect of Ce on the improvement of the oxide scale adherence is still obvious.Correspondent:LI Meishuan,assistant professor,(Institute of Corrosion and Protection of Metals,Chinese Academy of Sciences,Shenyang 110015)

Scanning electron spectroscopic analysis and membership function have been adopted to determine reliably the property region of welding joint and to furnish theoretical evidence for examination of microstructure and decision of grade.Correspondent:WANG Jialing,Faculty of Welding,(Department of Materials,Taiyuan University of Technology,Taiyuan 030024)

The model of dumbbell fibre-reinforced composite is put forwards from the viewpoint of biomimetics.The stress distributions in the enlarged-end fibre and in the matrix are analyzed.The axial stress in the fibre is found to increase and the interfacial shear stress decrease with the radius of the enlarged end.It is shown that for the fibre aspect ratio of lengh to diameter,a small influence on the stress state at the fibre end is expected.The effect of the fibre-matrix elastic modulus ratio on the maximum axial stress in the fibre,and the interfacial maximum shear stress between fibre and matrix is discussed.Correspondent:ZHOU Benlian,Professsor,(Institute of Metal Research, Chinese Academy of Sciences,Shenyang 110015)

According to the biomimetic research for fibres with enlarged ends,the model of imperfect-bonding interface and the strength theory of composite materials with perfect elastic-plastic matrix have been put forward.It has also been proved that the tensile strength of composite materials reinforced by fibres with enlarged-ends is higher than that by plain fibres.The theoretical and experimental results are in fairly good agreement.Correspondent:ZHAO Xiaopeng,(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110015)

The technology of SiC-coating by benzene solution of polycarbosiliane onto the surface of carbon fibres and the effect on the properties and structure of the coating,and the behaviours in preparation and performance of Al composites reinforced by this SiC-coated carbon fibres have been investigated.This SiC-coating effectively improved the resistance to oxidation of bare carbon fibres,the strength of it even down to 0.1μm in thickness and the wettabillity between the fibres and molten Al.Thus the interfacial chemical reaction may be prevented,and the strength of the composites increased to 189% of that with bare carbon fibres.Correspondent:WANG Yuqing,(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110015)