Superior hydrogen absorbability of the alloys of TiFe+xwt--%La with alternatelayer structure was found firstly. It would be available at 30℃ under 6 MPa H_2 without anyprior treatment.

Isotropic yield surfaces of both fcc and bcc metals have been simulated with theTBH model. Using the five--dimensional stress space proposed recently by Lequeu et al., theyield subsurface on any two of the three shear stresses can be considered approximately as in-scribed circles of their corresponding subsurface on π plane. Based on this concept, the HHHyield function has been transformed into the form where the parameters are uniquely deter-mined by two crystallographic factors: the mean Taylor factor in plane strain (M_p) and thecritical shear stress (τ_c) on slip systems.

The microstructure and various hydrides precipitated in Ti--6Al--4V alloys con-taining hydrogen 0.16, 0.58, 0.87, 1.49 wt--%, respectively, have been studied by means of TEMand X--ray diffraction. The Ti_3Al phase may precipitate when [H] over 0.58 wt--%. In thesame time, the morphology of hydrides gradually changed from rugged sheets to narrow laths as[H] contents increased. The microstructure of highly H--doped alloys is obviously fine. A mas-sive hydride and the hydride with tetragonal lattice were observed in the specimen containing1.49 wt--% H. The twin hydrides were found in the alloys with different H contents and theelectron diffraction patterns of the twin hydrides can be served as a simple criterion for distin-guishing the cubic and tetragonal structures.

Considering the availability and derivation of Roscoe's equation for absoluteviscosity calculation, the method to adopt λ_0 value, so-called λ_f, was proposed by experimen-tally determining relational curve of the measured height,H,of metal melt vs logarithmicoscillation decrement,λ, extrapolating H into zero, if such corresponding λ value is taken. Ex-perimental results show that the proposed method not only satisfies the availability of originalequation but also eliminate the effects of:"end and slippage", so as to improve the accuracy forliquid Cu and Sn examinations.

Using the dissipated energy as an essential parameter, the energy dissipativestructure in process of fatigue damage of materials has been established. Throughthermodynamic analysis for irreversible energy dissipation in fatigue damage process, the heatdissipative variations in cyclic loading process as well as in a cycle have been systematically stu-died on the basis of low cycle fatigue tests and infrared measurement of self-heatingthermography. Meanwhile, the cyclic hysteresis energy and efficicent energy dissipation (storedenergy) have been proposed during fatigue damage process.

The method to detect the crack initiation point of Charpy pre-cracked specimenunder dynamic loading was studied using strain gauge. The load-time curve and nominalstrain-time curve at the crack tip for impact testing specimens may be simultaneously measuredby twin-channel oscilloscope with high speed sampling and diskette storing. Based on the dy-namic finite element simulation of impact response of Charpy specimen, the measuring methodof dynamic fracture toughness was analysed and some problems in previous dynamic fracturetoughness measurement were discussed.

SEM microfractographic observations on fatigue crack propagation in thenear-threshold region were carried out 3 morphologies of morphologies of martensite and 6 du-al phase steels containing martensite. All of them are featured by cyclic cleavage facets, i. e.,mainly controlled by action of stress type Ⅱ. In the higher △K regions, the fracture surfaces arecharacterized by mixed modes including cyclic cleavage facets, two types of secondary cracksand striations. The roughness-induced crack closures of fracture surface is attributed primarilyto extreme high fatigue threshold value.

Plastic deformation of TiAl and TiAl-V intermetallic compounds has been stu-died by compression experiment at various temperatures and strain rates. Results show that theplastic deformation in distinct temperature range is principally controlled by the mechanisms ofPerierls-Nabarro, cross slip and creep of dislocation. For TiAl-V alloy deformed at a range of600--700 K, the negative strain rate dependence of flow stress was observed, i. e., the more theplastic strain is, the more the negative dependence will be. A possible mechanism of the anomalycould be interpreted by thermal activation of dislocation cross slipping. The effects of tempera-ture and strain rate on work-hardening exponent were also studied and discussed.

A criterion restraining method adopted to the dynamic optimization for materi-als heating process has been developed, regarding it as controlled object of a regulator in controltheory and combining the optimal criterion of it. The method may be available to optimize fuelsupply along furnace length and to provide a theoretical basis for the optimization of fuel supplyin time-varying. For soaking pit, the calculation shows that in case of optimization by criterionrestraining method, the thermal efficiency is 3.1% higher than the modelling prediction result.In comparison with heat flux-decomposing method, the thermal efficiency increased from 43.1to 43.8%, and the energy consumption was reduced by 7.28% relative to the practical produc-tion data.

Effect of reactive elements Y and Ce on high temperature oxidation ofFe-25Cr-40Ni alloy as well as on composition and microstructure of oxidized layer has beenstudied by ion backscattering and slow positron beam. The reactive element, not more than0.05%, may decrease the oxidation rate at early stage, accelerate the Cr_2O_3 growth, retard theFe and Ni oxides formation and improve the microstructure of oxidized layer. They enter theoxidized layer and concentrate within several tens nm from surface of outer layer. The resistancemechanism to oxidation for Ce seems to be different from Y. Ce may decrease the density of va-cancy defects in oxidized layer so that the diffusion outward of cations through vacancies is re-strained. While Y may affect the restraint of cations diffusion outward through vacancies at ear-ly stage to change into that along grain boundaries.

Studies were made of the influence of aging conditions and applied potentials onthe stress corrosion cracking (SCC) susceptibility, for an Al-Li-Cu-Mg alloy by slow strainrate technique. The relationship between the relative hydrogen content on specimen surface andthe applied potentials and elapsed time has also been examined. The SCC susceptibility wasfound to be dependent on aging conditions in which the peak aged condition gave the worstSCC resistance and the natural aged condition had the best one. The SCC susceptibility and sur-face hydrogen content are related to the applied potentials. The anodic potentials increase SCCsusceptibility, while the cathodic ones below the critical accelerate SCC. It is considered thatboth the anodic dissolution and hydrogen embrittlement contribute to SCC.

The Curie temperature increases but crystallization temperature decreases withthe increase of Ga concentration, x, of amorphous (Fe_(1-x)Ga_x)_(77.5)Nd_4B_(18.5) alloys. The averagemagnetic moment of Fe atom is almost a constant. By X-ray diffraction and thermomagneticmeasurements, the crystalline phases of the alloys, an unknown phase and α-(Fe, Ga) besidesFe_3B as major one, were identified. The room temperature coercive field with related to Ga con-centration was also studied.

A new empirical formula to calculate the optimum plate crown and roll camber wasderived as y=4P/a~2c (x~2+(B/2)x) It was fairly verified by production practice.

The combined method of γ-ray radiation together with hydrothermalcrystallization was firstly adopted to prepare the ultrafine particles of Cu or Au metal as well asCu-Au alloy. Discussions were also made of their nucleation, feature, size and stability.

Evaluation of adhesion of PVD Ti and TiN films on A_3 steel was carried out bya newly developed method, so called constant rate pulling test (CRPT) at 0.05mm/min, underSEM observation simultaneously. As the criterion, the critical cracking or spalling elongationof the film/substrate system on the one-sided polishing notched tensile specimen may be de-termined, respectively, to evaluate the plasticity and adherence of the film to substrate. Theconventional scratch test was also made for evaluation of the adhesion of films of the same sys-tems. Both give the coordinate assessment for all of the systems. In addition, the influence ofadhesion of the films to the substrate on ultimate YS of substrate material was discussed andanother criterion for adhesion assessment was proposed.

The effect of different regimes of heat treatment on the tensile strength of SiCcoated composite wires of carbon fibers reinforced Al has been investigated. Their tensilestrength may increase under treatment either at 500℃ for 2 h or 550℃ for 1h, but decrease over600℃. After the strength tests of extracted fibers from composite wires, the SiC coating is an ex-cellent protection to carbon fibers, EPMA and EDAX showed that the C/Al interface of thecomposite wires is stable under treatment below 600℃, but unstable at 650℃.

The Si_3N_4 whiskers reinforced 6061 Al composite material with bendingstrength 790 MPa was prepared by technique of squeeze casting. After heat treatment under T6regime, i. e. 530℃ 1h solutioning and 160℃ 24 h aging, an increment in strength andmicrohardness may be over 20% and 28% respectively. The microstructures of Si_3N_4 whiskersand Si_3N_4/Al interface were observed by means of HRTEM. The influence of interfacial struc-ture on properties was also discussed.