A systematic investigation of the influence of deformation on shaperecovery has been put forward in Cu-Zn-Al shape memory alloys in this paper.Starting at the model of the re-orientation of martensitic variants, the principle andessentiality of the influence of the amount of pre-deformation ε on shape recoveryrate η is elucidated.

The apparant activation energy of serrated yielding was measured bytwo different methods for a commercial brass H68. The results showed that theapparant activation energy of serrated yielding measured by a method involving(m + β) values increases with the grain size. In contrast, those measured by anothermethod without involving (m + β) values are all the same for specimens with differ-ent grain sizes. Combining with the observation of the microstructures the abovephenomena have been explained. The method to measure the true activation energyof serrated yielding has also been proposed.

The growth of bainitic ferrite is a couple process of the shear trans-formation of Fe atoms and the diffusion of C atoms. The diffusion growth of fer-rite is impossible when the temperature is below 400℃, and the paraequilibriumshear growth may occur at the temperature below 550℃. This paraequilibrium sheargrowth model explains the overlap of the bainites created from two growth mecha-nisms at 400--550℃.

The regular solution model developed by M. Hillert et al is appliedto calculate the driving force of bainitic transformation for Fe-C-Mn ternary alloysin the intermediate temperature range. Focus is made on the thermodynamical dis-cussions for both diffusional and shear mechanisms for bainitic transformations indifferent temperature ranges.

It has been found by TEM, SEM, EPMA and X-ray diffraction thatthe microstructure of the "white layer" formed on the surface of 55SiMo steelafter friction test by sliding consists of predominately friction martensite and someaustenite. The friction martensite exhibits peculiar features differen from that ob-tained by quenching or quenching and tempering. It is nanocrystalline (～30nm) withmicrohardness (Hm489) up to 1500. It shows good corrosion resistance and hightempering stability, capable of cutting glass, without appreciably altering its micro-structure and hardness below 500℃.

In consideration of the local equilibrium among vacancies, solute atomsand vacancy-solute atom complexes, and the influence of equilibrium grain bound-ary segregation, theoretical dynamic formulas for non-equilibrium grain boundarysegregation of solute have been derived on the basis of the vacancy-draggingmechanism. Theoretical calculation by computer has been carried out for the non-equilibrium segregation of B to austenitic grain boundaries during isothermal hold-ing and continuous cooling after heating at high temperatures. The results agree wellwith those obtained from experiments.

The categories of crystal faces for MC carbides in Ni-base superalloysby means of PBC theory confirm that {100}, {110} and {111} are F faces, and{212} are S faces. The caculations of attachmemt energy of each F face show that{111} are most important faces. It has also inferred that one of the growth unitsof MC carbides may be octahedrol molecula which consist of a metal atom sur-rounded by an octahedron of six carbon atoms. The attachment scheme of octahedralunits onto crystal should be layer grdwth mechanism on the {111} faces.

The microstructures of Fe-Mn-Ni-Cr steels with medium carbon andthe effect of alloy elements have been investigated by means of X-ray diffractionquantitative phase analyses, metallography and hardness tests. The volume fractionof martensite in steels quenched at 1100℃ can be expressed as f_M~(1100)= 162.643 - 15.482Mn - 7.36Ni - 4.286 (Cr + Mo + V)Based on this expression, the quasi-equilibrium microstructure diagram has beenobtained.

A mechanism of intergranular fracture of as-quenched martensite inhigh carbon steels has been proposed. When coarse grains of austenite transform tomartensite, the grain plays a role of the unit of volume dilation, inhomogeneousstrains necessarily produce and local microscopic stress concentrations create at grainboundaries. This reduces the integration of the grains, sometimes intergranutarcracks may produce. Under the action of first kind hardening stress or externalforce, the intergranular cracks propagated along the grain boundaries will form.This results in the candy-like fracture.

The fatigue fracture surface micromorphology in the near-threshold re-gion was studied in LD10 aluminum alloy and Ti-6A1-4V alloy. The SEM examina-tions show that the fracture surface of both alloys at low crack growth rates (1×10~(-7)—1×10~(-5)mm/cycle) takes on a cyclic cleavage facet appearance. The typical cy-clic cleavage facets were either sawtoothed facets or terraced facets for LD10 andisolated island facets for Ti-6A1-4V alloy. The paper explicated the mechanism ofnear-threshold fatigue crack growth on the basis of experimental observations

The substructure change of martensite in shape memory alloy Cu-14Al-4Ni agedat room temperature for 2 years has been observed. The domains of highly ordered phase andthe transition regions at grain boundaries appear, the twin boundaries damage. Furthermore,the microstructure also gives the appearance and growth of antiphase domains like rectangularnetwork. The long period antiphase structures and the antiphase domains have been cbserved atthe single diffracted vector g. The concentration gradient of Al has been found from the ma-trix to the grain boundaries, the matrix is poor in Al and the grain boundaries are rich in Al.

The characteristics and the formation of the V-Ti miscible particles in V-Ti-Nmicroalloyed steels were studied. It has been found that the vanadium to form V-Ti miscibleparticles starts to precipitate after pouring and cooling to temperatures below 1150℃ by meansof the epitaxial precipitation on the pre-existing titanium nitrides. The vanadium content in theparticles is markedly influenced by cooing rate solidification.

By taking the effect of oxygen contents into account, a new set offormulae which represents the oxygen potentials of H_2O-H_2 and H_2O-H_2-inerts gasmixtures has been derived. Classical representation is only a particular case of it.Some of the variables affecting the equilibrium atmosphere when trace oxygen ispresent and optimum preparation of the gas mixtures to minimize errors have beendiscussed. The reliability of some of previous equilibrium experiments under theoxygen potentials controlled by H_2O-H_2 or H_2O-H_2-inerts gas mixtures has alsobeen criticized.

The effects of Y, Ce and La on the sulfidation of alloy Fe-25Cr-40Nihave been investigated. The sulfidation rate of the alloys with RE more than 0.1wt-% is lower than that of the base alloy. The addition of Y is more effectivethan La and Ce in lowering the sulfidation rate. Based on the analyses of the struc-ture and composition of the sulfide scales. The sulfidation mechanism of the al1oyswith RE has been proposed.

Ternary phase diagram of the PrCl_3-NaCl-LiCl system has been deter-mined by means of DTA technique. It is found that this ternary system is com-posed of five liquidus surfaces, seven second crystaline lines, two peritectic pointsand one eutectic point.

The activity of MgO in MgO-B_2O_3 melt was experimentally determinedat 1500 and 1550℃ by means of slag-liquid Sn equilibrium. The activity of B_2O_3was calculated by integrating Gibbs-Duhem equation. The standard Gibbs energies offormation of binary compounds 2MgO·B_2O_3 and 3MgO·B_2O_3 were estimated withthe activity data of components in B_2O_3-MgO melt.

By inserting the single crystal silicon seeds into Sr modified A1-22wt-%Si alloy melts, the fact that nucleation and growth of Si-phase are affectedby Sr addition has been confirmed. It is suggested that this effect is caused by theadsorption of Sr on {111}_(si), and the modification of eutectic structure results fromthe variation of leading phase in the eutectic from Si to α-Al

The electrochemical alloying of Y-Cu system in molten NaCl-KCl-YCl_3 has been investigated. The free energy changes of the formation reactions ofthe intermetallic compounds, including YCu_6, YCu_4, YCu_2, YCu(973--1103K), weredetermined by means of electrode potential-time curves of the working electrodeafter potentiostatic electrolysis. The results indicate that the potential-time methodis simple and reliable.

The electrochemical behaviour, which is presented by means of ano-dic polarization curves, of the component phases in Ti and Ti alloys in aqueous so-lutions of fluorhydric acid, chlorhydric acid and amber acid has been investigated.The results indicate that the electrochemical behaviour of the alloy depends uponits composition and the lattice type. The corrosion of α and α' phase in active re-gion and that of β phase in passive region are the dominant corrosion behaviour.

The effect of boron content (0 to 2.22 at.-%) on isothermal oxida-tion behaviour of Ni_3Al at 750 to 1150℃ for 3 to 100h has been studied. Theresults show that the isothermal oxidation kinetics of Ni_3Al with various B contentsat different temperatures obeys the parabolic law. The compounds with 0.52 to1.37 at.%B show the best oxidation resistance. The morphology and microstructureof the scales have also been investigated.

The influence of rare-earth elements, La, Ce, Pr, Nd, Sm, Eu, Gd,Dy, Ho, Br and Yb on the thermal stabitity of PdSi_(16.5) glass wae studied systemati-cally by means of DSC. All rare-earth elements, especially heavy ones, increase ob-viously the thermal stability parameters, including T_A (T_g,T_x,T_p), T_(rg) and ΔE etc.The crystallization temperature T_(p1) and T_(p2) increase linearly with the lanthanideconstriction increasing, but Eu shows an anomalous influence: Pd-Si-Eu metallicglass possesses the highest thermal stability and the lowest concentration range ofglass forming among Pd-Si-R glasses

This paper, in which the influence of some factors on velocity fieldin continuous casting tundishes has been verified by means of computer simulation,is the extension of the paper "Fluid dynamics of continuous casting tundishes.These factors are tundish wall inclination; the dimensionless geometric size of tun-dish; the double-angle tundish; the dimension and location of weir and dam. Someuseful conclusions may be extracted finally for practice and design from this paper.

A study on the interficial activity behavior of flux during aluminumbrazing has been made by using metallography, SEM and electron probe techniques.The results showed that the activity of a flux is caused by the wetting of base me-tal with the liquid heavy metal reduced from the flux, thus, some regions of liq-uid alloy created, at which no aluminum oxide film covers on the surfaces. Thereduced metal drops are finally trapped in the fillet. The size of the metal dropsincreases with the decrease of brazing temperature.

Work hardening of Hadfield manganese steel is mainly from twocauses: 1) a large amount of twinning makes perfect dislocal is or shockley dislo-cations to be blocked up at the coherent twin boundaries. 2) deformation leads tostrong unsymmetrical distortion due to a large number of Mn-C pairs or Mn-vaca-ncy carbon-carbon clusters. It has been demonstrated by TEM observation and in-ternal friction tests. As deformation proceeds, slip constantly accommodates twin-hing shear giving rise to stress relaxation. Thus, Hadfield steel possesses both rapidwork hardening and good ductility.

# The activities of mercury in the mercury-lead binanv omalgam ???? neasured usinga high-temperature isopiestie technique at 600K. The activities ???ead in the ???ary amalgamwere also calculated using the Gibbs-Duhem integration.

Glow discharge cathodic sputtering of alloys containing second phase precipitatesor injection of oxide particles has been observed with an energy dispersive X-ray spectrometerand scanning electron microprobe. It was shown that the formation of cones during thesputtering in these alloys is due to masking of the matrix by glow sputtering second phaseprecipitates or oxide particles. At steady state, the number density was lound to be a functionof precipitate or oxide particle density in bulk alloys. In addition to local sputtering rate changes,the electrostate effect ?ay play a role in the formation of cones.