Observation of epitaxial overlayer of metals at atomic level has beensuccessfully observed in field ion microscope with 5 ns pulsed-laser heating. Thecondition of superlattice layer growth depends on the surface free energy and thelattice misfit. Many defects, such as vacancies, vacancy clusters, voids, dislocationsand twins are produced during epitaxial growth because of the lattice misfit eventhough the condition of surface free energy is satisfied. Alloying is observed tooccur on the surface of the metal during the epitaxial growth. Diffusion is proba-bly via the exchange mechanism.

The bonding layers in dissimilar alloy explosive bonding joints, γ/αstainless steels, copper/carbon steel and brass/γ-stainless steel have been studied bymeans of TEM technique. The results show that the bonding is obtained by diffu-sion and local melting at the contacted surface. The structure of bonding layer notonly responds to the compositions of the bonding alloys, but also the differencebetween their thermal conductivities, melting points and recrystallization tempera-tures. Because of the small molten region and fast cooling rate, the structure ofmolten region could be amorphous or microcrystals, and both stable and metastablephases exsist.

Streaks of austenite-rich and ferrite-rich bands produce during thesoaking at α+γ region because of the re-distribution of elements. Part of the aus-tenite formed at intermediate temperatures transforms into martensite while thesteel was cooled down to room temperature. The structure which consists of finemartensite and austenite exhibits a moderate strength and high enough cryogenictoughness. One of the important cause of the excellent cryogenic properties is thatthe precipitated austenite absorbs the impurities and thus purifies the matrix of thesteel.

The phase transformations in Ti-10V-2Fe-3Al alloy during aging havebeen studied by means of X-ray diffraction and TEM techniques. The morphologyand distribution of precipitated phases were examined. The lattice parameters of αand β phases as a function of the aging time is obtained, the hardness variationof the specimens related to the aging temperature and time has been given as well.

By means of nonstoichiometry, rapid solidification and adequate bo-ron addition, the tensile strength and bending resistance of Ni_3Al has been improved.When adding 0.52 to 1.37 at.-% B into Ni_3Al, which has the beneficial effect onthe ductility. If boron addition is too high, there are coarse Ni_(23)B_6 particles andNiB_(12) phases found on the grain boundaries. Boron modification in Ni_3Al promotesthe ordering in the region near grain boundaries. The grain boundary of boron freeNi_3Al is a large angle one, but turns into a small angle grain boundary with sub-grains of dislocation characteristics when the boron content in Ni_3Al reaches 1.37at.-%.

Three kinds of alloy carbides have been observed in tempered steel4335V: M_3C, M_7C_3 and M_4C_3. The precipitation temperatures are 200--700℃,>400℃and>500℃ respectively. The compositions, morphologies and distribution of thecarbides as well as the relationship between them and the quenching substrutureshave been investigated. The influence of the carbides on the low temperature im-pact thoughness of the steel has also been discussed.

Hydrogen induced cracking in a ferrite-austenite, duplex stainlesssteel has been investigated using compact tension tests. The stress intensity thre-shold K_H of the steel increases with increasing austenite content and decreases withincreasing current density during hydrogen charging. The hydrogen induced crack-ing initiates and propagates on {100} planes of the ferrite. The austenite plays a"fibre-tougthed" role during obstructing crack propagation.

The permeation curves of hydrogen in (α+γ) duplex stainless steelhave been electrochemically determined. The apparent diffusivity of hydrogen de-pends on the austenite content (fγ) at room temperature, D=(0.27+0.9/f_γ~2) (10~(-10)cm~2/s). It is simply verified that hydrogen in (α+γ) duplex stainless steel diffusesin "series-connection" form through both ferrite and austenite, the apparent diffu-sivity is D≈D_αD_γ/(f_α~2D_γ+f_γ~2D_α), where D_αD_γare respectively diffusivity of hydrogenin ferrite and austenite, f_α,f_γare volume fraction, in turn, of ferrite and aus-tenite.

Hydrogen induced cracking of 0.3% C,1% Cr, 1% Mn, 1% Si highstrength steel has been studied under simple mode Ⅰ, mode Ⅱ and (Ⅰ+Ⅱ) mixedmode loading conditions. After being hydrogen-charged in 1N H_2SO_4 solution, thematerial behaved hydrogen embrittlement in all the cases studied. The results showthat simple mode Ⅰ or mode Ⅱ loading are more susceptible to hydrogen embrittle-ment than (Ⅰ+Ⅱ) mixed mode. For explaining the experimental results, the effectsof hydrostatic tension as well as plastic deformation ahead of crack tip has beendiscussed.

Based on the experimental study of complex biaxial mode I fatiguecrack growth and the discussion on Von Mises theory, a new approach is pro-posed for correlating crack propagation rate under both in-phase and out-of-phasebiaxial stress cycling. The results emphasize the contribution of plasticity to fatiguecrack growth.

In shot peened α-brass surface layer {111} type planar defects anddeformation microtwins have been observed by means of TEM analysis. Thedensity of microtwins decreases with the increase of layer depth. The enhancementof fatigue strength and the unrelaxation of residual stress after shot peening areconcerned in the substructures of strengthened layer.

By means of HM-100 hot-stage microscopy, the in situ observation of γ→β trans-formation in steel 12Cr2MoWVTiB has been carried out The sequence of the growth of ferriticneedles composing bainitic basket has also been determined. A multislip system transform modelconcerning the formation of basket has been proposed.

The inieraction of hydrogen with intetface between the precipitates and the martens-itic matrix in 18Ni maraging steel has been studied by means of thermal hydrogen evolutiontechnigue using gas chromatograph as hydrogen detector. An evolution rate peak has been obser-ved at 451K. The hight of the peak relates to the amount and distribution of the precipitates.The activation energy needed to escape the hydrogen from the trap sites is 23.2 kJ/mol.

The microstructures of the laser hardened layer on the gray cast iron HT20--40 af-ter laser melting processing were examined by optical microscopy, transmission electron microscopy(TEM) and scanning electron microscopy (SEM). Experimental results showed that a structurewith dendritic (M+A') and interdendriticly iaminal transformed ledeburite (M+A'+Fe_3C) wasproduced after laser melting processing. The martensite was a mixture of dislocation martensite andtwin martensite. Dislocation pile-ups and twins were found to exist in the residual austenite.Microsegregation of composition and heterogeneity of microstructure were also apparent after lasermelting processing.

An investigation was made on the Possibility of using Ni-x binary diagram to ju-dge the positive, negative segregation or almost no segregation and degree of segregation of alloyingelement x in cast Ni-base superalloys. The prejudicat coincides with the experimental data.

Solubility of Ca in manganese and manganese alloys was measured un-der sealed conditions at 1350℃. The interaction coefficients of Al and Fe on Cain Mn were evaluated with the experimental data. The standard free energy ofliquid Ca in liquid manganese based on thel wt-%. solution standard was estimatedas well.

In grey cast iron, sulfur is concentrated in the liquid, flake graphiteand on the edge of D-type supercooled graphite eutectic cells, but less sulfur is inaustenite. Besides, the content of sulfur in A-type graphite is higher than that inDtyp graphite, and the sulfur content in eutectic austenite is a little higher thanthat in primary austenite. While in nodular cast iron, less sulfur is in liquid andaustenite, but more in nodular graphite.

The solid oxide electrolyte galvanic cell represented by Mo

The internal oxidation behavior of Pd-40Ag-1M (M=Zr,Y) alloywires has been studied in air at 800--1200℃. The relationship between the internaloxidation depth ξ and the reaction time t can be expressed as ξ=Kt~n, wheren=0.5--0.75. The higher the temperature is, the larger the n value is the activeelements Zr and Y have different iniernal oxidation characters. For the alloys con-taining Zr, the oxidation rate along the grain boundaries is about twice as thatin grains, and "lateral speed oxidation" exists along the grain boundaries. For thealloys containing Y, the oxidation in grains and along the grain boundaries is rough-ly the same, and do not have "lateral oxidation" along the grain boundaries. Theactivation energies of both alloys are in the range of 120--150 kJ/mol. Some pro-perties of internal oxidized alloys were studied.

The synergistic extraction of Cd (Ⅱ) with primary amine N--1923and neutral organophosphorus reagents (TBP, DBBP, B) from hydrochloric acidhas been investigated at μ=0.5, t=25℃. The compositions of the synergisticextraction complexes and the mechanism of the synergistic extraction have beendatermined by the methods of slope and constant mole. The synergistic extractioncomplexes with composition (RNH_3C1)_2. CdCl_2.B have been demonstrated. Thesynergistic extraction reactions and additional reaction of Cd (Ⅱ) have beenproposed as follows:CdCl_2+2RNH_3Cl_(o)+B_(o)?(RNH_3Cl)_2. CdCl_2.B_(o)(RNH_3Cl)_3. CdCl_2_(o)+B_(o)?(RNH_3Cl)_2.CdCl_2.B_(o)+RNH_3Cl_(o)In addition, the equilibrium constants and the thermodynamic functions of the syn-ergistic extraction reactions have been calculated. The IR and NMR spectra of thesynergistic extraction complexes of cadmium (Ⅱ) have been studied as well.

The short-range order structures of Fe_x Ge_(1-x). amorphous thin films(x=8.7, 19.1, and 28.5%) have been studied by X-ray absorption spectrum. Thenearest neighbors around a Ge or an Fe atom constitute two coordinate sub-shellswith a very short distance. In two films with lower Fe content, structural para-maters of the nearest neighbors around a Ge atom are similar to that in amorphousgermanium and the positions of Fe atoms are randomly substitutional. But whenX=28.5%, some great changes occur on the short-range order structure ofα-Fe_x Ge_(1-x) film: its structure deviates from continuous random network and tendstoward dense random packing of atoms. Meanwhilee, there is stronger interactionbetween near neighboring Fe-Ge atoms in a-Fe_x Ge_(1-x) films.

To study the growth of austenitic shells around the spheroidal graph-ite, color metallography has been employed. It is found that the shell is not acontinuous layer of austenite, but a cluster of wedgeshaped crystals. Three typesof shells has been observed. That may strongly affect the deterioration of the sphe-roidal graphite. The mechanism of the formation of the austenitic shells has alsobeen discussed.

The reactive spread behaviour of Cu particles on the surface of Alhas been studied. The role of oxide film and the formation mechanism of the jointduring Al/Cu contacting reaction brazing have been discussed.

The mechanical properties of regenerated W-alloys relating to thechemical purity and size of reclamation powders of 93W-Ni-Fe-Co (Mn) alloychips, the structure of main constituents of the powders, as well as microstructureand fractograph of regenerated W-alloys made by the reclamation powders, compo-sition of W particle and binder phase, content, structure and distribution of mainimpurity elements have been studied by means of optical microscope, SEM, XRES,XRD, TEM, AES and chemical analysis. The feasibility of oxidation-reductionprocess for reclamation and the possibility of practical application of regeneratedW-alloys have been discussed.

The adhesion between the ion plated TiN coating and the base metalis improved by adding Y. By means of SEM, EPMA and X-ray diffraction analy-sis, the behaviour of Y in coating has been studied. The machenism of the effectof Y has been discussed as well.

Experiments clarified that the application of maximum entropymethod to calculate the RDF (radial distribution function) of the Ni-P amorphousalloy from its X-ray diffraction data shows a higher resolution and good consistentwith know results with less data. It is believed that this method is available forthe analysis of amorphous structure.

The liquidus of ternary system NdCl_3-MgCl_2-LiCl has been determined by meansof DTA. It was found that there are two surfaces corresponding to the primary crystallization ofNdCl_3 and α-(MgCl_2, LiCl) respectively, and an univariant line related to the secondary crystal-lization with a minimun point M (68.5 wt-% NdCl_3, 2.7 wt-% MgCl_2, 28.8 wt-% LiCl, 441℃)in the system.

The corrosion fatigue propagation behaviours of low carbon martensitic steels20Cr2Ni4 and 20SiMnMoV have been investigated in 3.5%NaCl solution spray. The fatigue growthrates of two steels in salt spray are much higher than those in air under low △K range. A crit-ical stress intensity factor range has been observed for each steel. The crack prowth stoppagewill occure if the △K value was lower than it.