The behavior of void swelling and segregation in Fe-15Cr-xMn alloysand alloy coataining small amount of W and V was investigated by electron-irradiation. The compositional analysis in the irradiated regions including grainboundaries was performed. The results show that there are many common featuresof irradiation behavior in the Fe-Cr-Mn and Fe-Cr-Ni systems while there are somesignificant differences. In the Fe-Cr-Mn alloy systems void swelling was remarka-bly suppressed and at the same time the radiation-induced segregation was also re-tarded, furthermore, the segregation was strongly retarded in Fe-15Cr-15Mn alloycontaining small amount of W and V. The results also show that Ni replaced byMn does not in general confer immunity from either swelling or phase instabilities.The phase instability is due to the different diffusion behavior of Ni and Mn inresponse to the operation of the inverse-Kirkendall effect. Fe segregates to the mi-crostructural sinks in the Fe-Cr-Mn alloys. The segregation of Fe often leads tothe formation of ferrite. This fact is beneficial to reduce the swelling rate andsegregation on the grain boundaries.

A rapidly solidified microcrystalline Al-Li-Cu-Mg-Zr alloy and itssuperplasicity have been investigated. An optimum tensile elongation of 585% wasobtained at 540℃ and strain rate 1.67×10~(-2)s~(-1). The superplastic Al-Li alloy is ma-nufactured using thermomechanical processing: solution, overaging, warm rollingand recrystallization. Microstructural changes in thermomechanical processing andcavitation occurred during superplastic deformation have been observed. The super-plastic failure of alloy may be caused mainly by nucleation and growth of cavitiesas well as the linkage around grains.

The grain boundary internal friction in Fe-P and Fe-P-La alloys con-taining a little Cu has been studied. The internal friction is obviously reduced byLa added even 0.584-0.722 wt-%. The grain boundary peak migrates toward thehigh temperature and a small internal friction peak occurs. The grain boundaryinternal friction seems to be interpreted by movement, under stress, of both thedefects of atomic size, namely point defects, in grain boundaries and their clusters.

The effect of alloying elements such as Mo, Si or B and its stoichoi-metric composition on the tensile properties at room and elevated temperatures, andalso on the microstructure has been investigated. Two Fe aluminides were found tobe obviously strengthened by all of three elements, but seriously embrittled by Moand Si. An improvement over the plasicity of FeAl may be made by adding B. Thefracture surface is varied from intergranular to transgranular cleavage type. Theroom temperature plasticity of the Fe-rich Fe_3Al or Al-rich FeAl is much betterthan that of the stoichoimetric aluminides. An anomalous temperature dependenceon the yield strength of Fe_3Al in range of 400 to 550℃ or of FeAl in 400 to500℃ was found. Discussion has been carried out by the aspect of microstrutures.

The activated slip systems in the α-phase of the superplastically de-formed Ti-6Al-4V alloy were analysed by systematic operation method with TEM.The results show that the dominantly activated slip systems in the α-phase are{0110} <21l0> and {0111} <2110>. The {0001} <2110> system as well as the c+αdislocations of b=1/3<1133> will be activated when the deformation temperatureis lowered. Large amounts of TEM observation indicate that the dislocations in theα-phase were mainly activated near the triple grain boundary junctions, α/α grainboundaries, and α/β interfaces.

The statistical model for the fracture toughness of a modified Al-7Si-0.45Mg cast alloy has been proposed on the basis of analysis of the correlationbetween the size distribution of crack nuclei and Si particles and of the microme-chanism of fracture. The suitable criterion of fracture toughness according to themodel has been given. The model has found a good explanation for the fracture.feature, fracture toughness and microstructure, and agreed with the experiments-very well.

The morphology of the retained austenite in the carburized case overthe 20CrNiMo steel and its transformation during fatigue crack propagation throughthe case were investigated by using X-ray and TEM analysis. In the carburizedcase, both film and block shared retained austenite were found. The fatigue crackis inclined to pass through the block shaped retained austenite and thereby stimu-lates its strain-induced martensitic transformation, due to the effect of the orienta-tion relationship between the surfaces. During the process of the fatigue fracture,most of the retained austenite on the crack path are transformed into the marten-site, and the untransformed amounts on the fracture are remained less than 6%. Thetransformation of retained austenite, which is restricted mainly within the plasticzone, occurs only in the time of the fracture, and is independent of external stressesand stress ratios and cyclic numbers. The volume expansion accompanided by itstransformation creates an additional residual displacement of about 0.44μm oncracked surfaces, which is relevent in the magnitude to the plasticity-induced residualdisplacement. The phase transformation induced fatigue crack closure is believed tobe an important factor affecting the fatigue crack behaviors in the high carbonlayer of the carburized case.

The fatigue tests were made on the specially designed specimens by avibration testing machine to investigate the initiation and propagation features ofshort fatigue cracks in a weld metal. The specimens were prepared of a kindof triangular shape in which the surface tensile stress is a constant. The resultsshow that the short fatigue cracks originate from the slip bands and initiate insidethe ferrite grains. The development of short fatigue cracks is marked by the grad-ual increase in crack density with fatigue cycles. The coalescence between shortcracks leads to crack propagation and the crack path is predominantly transgranular.

In the light of research on the microfeature of cleavage fracture oflow carbon steel, the stress criterion for cleavage crack propagating across ferritegrain boundary was established on the supposition that resistance to the propaga-tion results from an arbitrary mutual orientation of the cleavage planes in theneighbouring grains. On the basis of concept of statistical spatial distribution ofcleavage plane, the characteristic of probability on cleavage process was expounded,and the fracture stress of the cracked specimen over temperature range in whichfracture is initiated by cleavage mechanism was calculated by means of finite ele-ment analysis programm and the calculated result was found in agreement with thatmeasured.

The thermal crack of the train vehicle wheel is believed to be rela-ted mainly to its carbon content and hardness. The wear rate of wheel tread isinfluenced by fracture toughness of the new martensitic "white layer" while thecomposition shoes applying. A 55SiMn steel wheel of resistance to thermal crackand wear has been developed with remarkable feasibility in usual run.

The surface alloying specimen was made of the steel 45 substrate overcoating byoxygen-acetylene flame spraying Fe-Ni-Cr alloy powder and laser remelted. The chemical heter-ogeneity was clearly observed on the transition zone between the laser melted zone and heat-affected zone by means of EPMA, AES and SEM. This heterogeneity is rather serious duringhigh temperature tempering, so the decarburization on the transition zone side and the recarbu-rization on the melted zone side were found.

The neutron diffraction of Nd_2(Fe_(0.9)Si_(0.1))_(14)B has been measured at room temper-ature and 77 K. Their data were fitted by profile analysis method. From the data at room tem-perature it can be got that Si occupied preferentially the sites 4c, 8j_1 and 16k_2; the magneticmoments, both Nd and Fe, are parallel to C axis. From the neutron data at 77 K it can beshown that Si still occupied the same sites as the sample at room temperature, but the data fitwith Nd moments deviating C axis and Fe moments parallel to c axis is better than all mo-ments parallel to C axis. It seems to prove that the Nd spin reorientation takes place at 77 K.

An investigation has been made of the fine structure variation of thepolycrystalline Cu-Zn-Al shape memory alloy under martensite deformation by meansof TEM observation. Deformation, in the initial stage, is accomplished by thereorientation of variants, but the reorientation is often incomplete. After furtherreorientated, the interfaces among the prior variants still remain. A lot of twinswill appear in martensite under enormous deformation, and the twin plane is (001).The dislocations occur in some regions. In this case, the martensite will lose itsthermoelasticity and the shape memory effect will be damaged.

A possible mechanism of all-round shape memory behaviour by help of a physi-cal model proposed by Muller has been ascertained. The all-round shape memory effect can bedue to the fact that stress induced martensite of two different orientations is formed duringthe martensitic transformation in the outer and inner layers of the specimen respectively.

The structure and properties of molten salt solution of Li, K | F, Clsystem have been investigated by computerized simulation of molecular dynamicsmethod. The partial RDF, the partial molar energy of mixing and the diffusioncoefficient of Li~+, K~+, F~- and Cl~- have been calculated. The results of calculationare in agreement with the experimental values. The regularities of the distributionof ions and holes are discussed based on the results of computerized simulation.

Interfacial tension between liquid Al and molten fluoride salt wasdetermined using sessile drop method combined with X-ray radiograph. A compu-ter program of curve fit for coordination of configuration of sessile drop was usedin the picture processing of the sessile drop. Regressive equations were worked outto calculate density of the molten salt. Influence of mole ratio of NaF/AlF_3, contentof Li_2CO_3 and rare-earth oxides in the molten salt on interfacial tension of Al-saltwas discussed. The contact angles of liquid Al on the surface of graphite, graphitizedcarbon cathode and the graphite with coating of TiB_2 were determined.

Equilibrium between liquid Fe containing Nb with Nb_2O_5-MnO-SiO_2slag was investigated at 1828 K, the solid electrolyte oxygen concentration cell be-ing used to measure the activity of oxygen in the metal bath. The activity of Nb_2O_5and MnO in the slag was evaluated, accompanied with an iso-activity diagram ofα_(Nb_2O_5) and α_(MnO) in Nb_2O_5-MnO-SiO_2 slag.

A modified ion-plated IP-TiN coating has been developed by adding6 wt-% elementary Al and various small amounts of La. Examination of this coat-ing shows that the adhesion between the coating and substrate may be remarkablyimproved by the La added up to 2 wt-%, and the microhardness and wear resistanceof the coating surface may regularly change with the increase of La content. EPMAand X-ray diffraction analysis showed that the Al and La added are concentratedat the interface of the coating/substrate where a thicker transition zone formedwith an alternation of phase composition and grain orientation of the coating.Thus, an improvement over the properties of coating was proposed.

Acoustic emission (AE) behaviour during fatigueing in either air or3.5% NaCl solution has been studied for a structural steel (SM50B-Zc) in quenchedand normalized states. The experimental results show that AE activity is affectedstrongly by heat treatment and condition of environments. Some material constantsabout AE resulted from the good relation between AE parameters and fatigue para-meters.

The residual stress of the coating Ti (CN) on Nb-752 alloy was mea-sured using free bending method to be 2-3 GPa in which the thermal stress amount-ed to 10-20%. An analysis on the coating/substrate interface stress shows that theshear stress at it is about 0.1-0.2 GPa. The damage mode of the coating underexternal loading was proposed in terms of the amount and the direction of loading.

An electrochemical model, directly deduced from the principle of elec-trochemistry, together with the calculational method for initial oxygen potentialalong the metal-slag interface may be available to quantitatively describe the plotof %S vs time. It was found that during desulphurization both the distribution con-stant of S along metal-slag interface, L_S~*, and distribation index inside the bulk,L'_S, vary with the descending of oxygen potential along metal-slag interface. Butthe plot of L_S~* vs time is quite different from L'_S vs time, being of parabola or hy-perhola type respectively. The variation of the driving force parameter vs time,obtained either calculated or experimental, plotted as a camel hump.

For two common types of liquid-solid heterogeneous reactions, thekinetic eqtiations have been established which involved both the variation of liquidreactant concentration and the variation of solid reactant geometry with thereaction time. The experimental results show that the kinetic equations are moreaccurate and reasonable than those appeared in previous literatures. Moreover, theyare also suitable for gas-solid heterogeneous reactions in principle.

The separating efficiency of Sb from As and Sn may be improved bychanging the composition of extract and the testing condition for leaching fromjamesonite concentrate. The related kinetic parameters of electrode reaction wereevaluated under discussion on the form of complex ion AsS_3~(3-) in extract and thereduction at amalgam electrode. It was also discussed about the effect of concentra-tion of Na_2S and SbS_3~(3-) in solution on the current efficiency of SnS_4~(4-) reduction.

The reaction kinetics model for the synthesis of ultrafine TiN pow-der from vapour phase system TiCl_4-NH_3-H_2-N_2 in the high frequency plasma reac-tor was proposed as follows: (-r_A)=-1/v(dn_(TiCl_4)/dt)=0.852e~(-63.2/RT)P_(TiCl_4)The majority of factors influenced upon the reaction be were analysed, so as toprovide the theoretical basis for improving quality of TiN powder and for opti-mizing the design of plasma reactor.

The infrared emission from the high strength steel for thin-wall pres-sure vessel and from two vessel models themselves during loading has been examin-ed by use of vibro-thermography. The fatigue crack lengths observed on infraredvibro-thermogram are found to be in good agreement with that by optical measure-ment. Thus, a feasible nondestructive defect detecting test for the pressure vesselmay be suggested.

Three surfaces corresponding to the primary crystallization of PrCl_3, CaCl_2 andMgCl_2, respectively, 3 univariant curves related to the secondary crystallization and a ternaryeutectic (44.8wt-% PrCl_3, 31.8wt-% CaCl_2, 546℃) were found in the system PrCl_3-CaCl_2-MgCl_2 by means of DTA. A reaction occurs in this system: L=PrCl_3+CaCl_2+MgCl_2.

The needle-like and network carbides in wear-resistant high carbon manganesesteel as-casted will be nodularized and dispersed. by a large majority, in austenite after modi-fication with Mg system agents. The impact toughness of the steels may be obviously improvedand the hardness also increased to a certain extent. And therefore it seems to be available whenthe steels are still as-casted, and no necessity of heat treatment may be often made to bettertheir wear resistance.

An experimental study has been made of the oxidation of Ti in molten Cu-Tialloy under watery atmosphere at 1500℃. The results may be expressed as follows: [Ti]_(Cu)=0.92-0.69t 0≤t≤1.0 (h) [Ti]_(Cu)=0.02t~2-0.14t+0.35 1.0≤t≤6.0 (h) The apparent rate and orders of related reaction are: -d[Ti]_(Cu)/dt=0.69, pseudo-zeroth order, k=0.69 -d[Ti]_(Cu)/dt=0.14-0.04t, pseudo-0.85 order, k=0.39 The apparent mass transfer coefficient k'_(Ti)=0.16cm/h, and the relation of W~2 vs time: W~2=1.04×10~(-4)t