The relationship between the microstructures, properties and the phasetransformation in Al-2.2Li-2.5Cu-0.2Mg alloy after various treatments have beenstudied by optical microscopy and TEM observations. It is verified that solutiontreated at 525℃ for 1h is satisfactory for this alloy in which all the alloying ele-menis are dissolved in the α-Al matrix, and aging at 190℃ for 16h is the peak-aged con-dition, the alloy subjected to treatment is strengthened only by T_1 phase. In over-aged or underaged conditions, the alloy are strengthened by two phases, in thesecases, the strengthening effect is smaller than that by one phase. The deformationprlor to aging would develop the plasticity and do not decrease the strength of theexperimenial alloy.

The phase structure of Ti-Cu_(1-x)-Fe_x with x=0.1--0.6 were investigatedby means of Mossbauer spectroscopy, X-ray diffraction and microprobe. The resultsshow that there are γ -TiCu and Ti(CuFe) Phase with CsCl type structure in thealloys of x=0.1 and 0.2. Single phase of CsCl type was found in all other allays.The solubility of Fe in γ-TiCu lattice is merely 1at.-% and the Cu content in CsCltype structure is up to 37.5at.-%.

Influence of the grain size and ordering degree of the parent phase onthe shape memory recovery in a Cu-25.62 Zn-3.97 Al-0.0018B (wt-%) memory alloyis investigated. A mathematical relationship is set up between the recovery ratio andordering degree, probability of atoms at their ordered sites, grain size, the widthof the grain boundary affected regions, the stress during deformation, as well as thecritical shear stress. Shape memory effect reaches a maximum with varying grainsize and increases linearly with increasing ordering parameter, that agrees well withexperimental results.

Plastic deformation of three CuZnAl shape memory alloys in martensi-tic state was investigated by means of optical and electron metallography, dilatome-try and electric resistivity determination. Two of the alloys are in martensitic stateat ambient temperature, and the A_f temperature of the third one is far below theambient temperature. The effect of deformation of alloys in martensitic state onthe course and temperature of transformation as well as the hysteresis of transfor-mation cycles has been analyzed and the "effect of the first cycle" has also beendiscussed.

Electron microprobe technique, Auger electron spectroscopy and EDSanalysis on TEM were used for measuring the phase boundary segregation of Mg ina Ni-base cast superalloy. The results show that Mg segregates to the phase bounda-ries of MC/γand γ′/γ. The thickness of Mg on MC/γ phase boundaries is latgerthan that on γ′/γ phase boundaries. The results prove that Mg is not only a grainboundary segregation element, but also a phase boundary searegation one.

The precipitation hydrides induced by stress were found to be gammaphase with orientation relationship of (110)_γ//(1120)_(αZr),(001)γ//(0001)_(αZr)between γ-hydride and surrounding matrix. The growth of-hydrides exhibiter a quickest ratealong [110] direction, that brings them in taper shape. After cracking at hydridematrix beundary, a new one will precipitate at the tip of cracks. This isthe essential process of hydrogen-induced delayed cracking in zircaloy The pre-cipitating hydrides induced by strain were found to be delta phase Phase with bothorientation relationships of (111)_δ//(0001)_(αZr)(110)_δ//(1120)_(αZr) and (010)_δ//(0001)_(αZr)(001)_δ//(1120)_(αZr) between δ-hydride and surrouding matrix. The δ-hydride becomesmuch finer as the strain rate increased.

A new point of view on the homogenization treatment has been pro-posed. It is supposed that a little liguid in the alloy may promote the homogenizationprocess in some aspects and reduce the time for eliminating the laves-phase in alloyGH169. The microprocess of the elimination of Laves-phase in the case of a littleliguid existing in the alloy has also been described.

The evolution of dislocation structures in 6% prestrained steel 1018during fatigue has been studied by TEM. The dislocations are quite movable, theloose cells quickly change to "checkboard" structures, in which the main cell wallslie about{100}. Then, the low energy dislocation structures-dipolar walls and laby-rinth structures are evolved. The characteristic of labyrinth and the orientation of di-polar walls are quite similar to f. c. c. crystal, it indicates the energy state of systemand the moving ability of dislocations are important factors affecting softening pro-cess, rather than the slip geometric characters of dislocations and details of disloca-tions. The decreasing in misorientation between adjoining cells and internal stressare discussed.

The change of microstructure of fatigue specimens before and after la-ser radiation was studied by transmission electron microscopy. The results show thatthe diameter of dislocation cell λ tends to a constant λ_c at fatigue failure. Based onthe principles of continuuous damage mechanics, expressions of the fatigne damagecriterion and processes of fatigue damage evolution for LY12CZ have been derived.

In the ferrite grains, the dislocation emitted by the crack tips maycross-slip out of the original slip planes and form a broad plastic zone. However, inaustenite, the dislocation free zone is small and the dislocations emittee by the crackpile-up in its slip plane. The selection of the slip planes at the crack tip depend onthe Schmid factor of crack tip in both phases. But after large deformation, the se-lection of the second slip systems at the crack tip in austenite does not depend on theSchmid factor.

The effect of pearlite interlamellar spacing of steel T_8 on fatigue crackpropagation near threshold has been investigated at different stress ratios. The clo-sure intensity factor, threshold value and crack tip opening displacement range weremeasured.

Optical microscope, SEM and IMMA investigation show that a strong interactionbetween hydrogen and calcium aluminate inclusions cotaining Mg may occur in medium carbonsteels. That causes the hydrogen accumulating around the inclusions and reducing the ductilityof the steel.

Trace of B and Ga can substitute for Mo in Mn-Si-Cr dual phase steels. Thetechnological properties and CCT curves of steels treated with B and Ga are similar to those forMn-Si-Cr-Mo steel.

The results of the contacting fatigue tests for Cu-22%Pb plain bearing alloyshow that the fatigue failure behavior of the alloy is related to the distribution of Pb particles.Both the additions of mischmetal and sulphure can refine the Pb paticles. However, mischmetalimproves and sulphur deteriorates the fatigue property of the alloy.

TiN inclusions are the major inclusions in Ti-stabilized stainless steels.The content and distribution of them closely depend on the casting process. TiN is akind of buoyant inclusions and can grow up gradually in molten steel during float-ing up. The sequence of the formation of inclusions in the steel is: oxides, nitridesand sulfides

A kinetic model for carbide diffusion coating has been proposed basedon the theory of steady diffusion and solid solution sublattice model. It is supposedthat the growth velosity of carbide layer is controlled by the volume diffusion coef-ficient of carbon atoms in carbide layer and the activity of carbon in steel matrix.The calculated results for V_4C_3 coating treatment of commercial steels T10, 45, Cr12MoV, 4Cr5MoVSi are in agreement with the experimental data

The mathematical formulas are given for calculating the partial molarthermodynamic properties in a ternary system from its three corresponding binary sys-tems based on the new ternary symmetric model presented by the authors in theforegoing paper. Applying this model to NaCl-BaCl_2-SrCl_2 system, the phase diagramof which as well as some isothermal sections have been calculated. The deviations oftemperature between the calculated and experimental diagrams are less than five de-grees.

The interfacial tension between FeO-CaO-SiO-MgO system slag andCu-Fe-S system matte was determinated by the X-ray radiograph sessile drop method.The effects of FeO/SiO ratio in the slag, contents of CaO, FeO, ZnO and CaF_2 inthe slag on interfacial tension and the relation of interfacial tension with the gradeof matte and temperature have been studied. The floatation coefficient and film coef-ficient of slag-matte system has been calculated and the mechanism of the transitionof iron and oxygen from slag to matte has also been discussed.

The thermal expansion anisotropy appears in all specimens preparedunder various forming conditions. The expansion along the longitudinal direction isless than that along the transverse direction. The cooling rate, the temperature of meltbefore jet casting and the cycling temperature affect the thermal expansion coeffi-cients and anisotropy. The anisotropy of thermal expansion originates from the direc-tional atomic interaction force, atomic oscillatory frequency and the directional shortrange order structure or defects in the alloy

The fracture strength and hardness of TiB_2 materials increase by addi-tion of 20--30 wt-% B_4C and the fracture toughness still remains on the original highlevel. The mechanism of reinforcement and crack propagation have been discussed

The dynamic tensile processes of silicon carbide whisker reinforced Alcomposite (SiC_w/Al) with 22% V_f have been in situ observed with a scanning elec-tron microscope equipped with a tension stand. The results show that a number ofmicrocracks have formed as the tensile stress goes up to 180--190 MPa. The fracturebehaviour of SiC_w/Al composites observed in this work has been explained theoretia-cally.

The techniques for surface analysis including AES, XPS and SIMS wereemployed to study the chemical composition and bond valence of nitrogen ion im-planted surface of surgical implantation service alloy Ti6A14V. The depth of implant-ed nitrogen ions and the sputtering rate of argon beams were determined using pro-filometer. It was found that the combination of injected nitrogen ions with titaniumresulted in the formation of hard TiN particles and the profile of nitrogen concentra-tion approximately displayed gaussian distribution. The total depth of implantednitrogen is about 350nm and its maximum concentration appers in the depth ofabout 140nm from the surface, in which the concentration ratio of nitrogen to tita-nium may be up to 1.1.

Simulative study on corrosion of Al_2O_3-C refractories by mold coverflux has been carried out by means of immersion method. The results show that therefractory exhibits best resistance to the flux while the ratio of additive Al and Si isapproximatly equal to one.

The relationship between partition ratio at solid-liquid interface andtemperature gradient or external force field has been theoretically analysed. It isshown that under the action of temperature gradient or external force field, the partitionratio at solid--liquid interface will deviate from the equilibrium value.

The room temperature section of Cu-Dy (≤35wt-%)-Ni ternary phasediagram has been determined by means of X-ray diffraction technique. The resultsare as follows: four single-phase regions (α, Dy_2Ni_(17), DyNi_5 and DyCu_5), five two-phase regions (α+Dy_2Ni_(17), Dy_2Ni_(17) + DyNi_5, DyCu_5 + DyNi_5, α+DyNi_5 and DyCu_5+α)and two three-phase regions (α+ Dy_2Ni_(17) + DyNi_5 and α+ DyNi_5 + DyCu_5) exist in thediagram. NO any new phase has been observed. The solubility of Dy in α-phase isup to 2wt-%.

An expert system, IMEC, for the retrieval and prediction of binaryintermetallic compounds has been built in our laboratory. The rules found by che-mical bond parameter-pattern recognition method have been used for computerizedprediction. Data base of known intermetallic compounds and chemical bond parame-ters of metallic elements and the knowledge processing system are included in theexpert system. By man-machine interfacing, the formation, stoichiometry and crystaltype of all biliary intermetallic compounds can be predicted or retrieved.

Magnetic anisotropies of the amorphous alloy Fe_(71)Ni_(10)B_(13)Si(14)C_2 annealed in mag-netic field have been studied using Mossbauer spectroscopy and X-ray diffraction. It is shownthat the distribution of moments in the annealed sample are determined by both stress-producedand thermomagnetic treatment-induced magnetic anisotropies.

The surface film on Si-bearing stainless steels formed aftersoaking in concentratednitric acid for 216h was investigated by means of electron energy spectrum analysis. It canbe reached from this investigation that Si builds up in the surface film in the form of silica.It plays as a main passivating element in Si-bearing stainless steels in strong oxidizing medium,whereas Cr drops into the second place.

Arbitrary incomplete measured pole figure (except that of {100}) of cubic materi-als can be completed by using the fundamental equations of the vector method and employingthe measured data as constraint conditions. The prediction of this method is in good agreementwith experimental results, and the analysing procedure has been proved to be simple and ef-ficient.

We report the experimental results of the prepartion of YBaCuO superconductorthin film on Si (100) substrate by the method of ion beam sputtering deposition. A ZrO_2 buf-fer layer was applied to Si (100) substrate, and was found to play an important role in resist-ing the diffusion of Si toward the film. The thin film is mainly a 123 phase with strong c-axispreferred orentation. The onset transition temperature of the film is 100 K and the finaltransition temperature 78 K.