Three point bending and dual cantilever model of dynamic mechanical analyzer (DMA) were used to measure the damping capacity of FeCrMoCu alloy, and ABAQUS software was selected to analysis the stress distribution of sample during damping test. The influence of stress on damping behavior of FeCrMoCu alloy was studied. The results show that there obviously exists stress concentration due to pre- load during damping test, which will cause the move of magnetic domain wall. With increasing stress, the mobility of domain wall will be lowered and the damping capacity of FeCrMoCu alloy decreases obviously. There is obvious influence of stress loading mode on damping behavior of FeCrMoCu alloy. For dual cantilever model, there always exists compressive stress at the upper and lower surface of test sample and a greater stress is needed to saturate domain structure. Therefore, the strain amplitudeεmax is bigger and the maximum damping capacity Q^-1_max is lower. While 3 point bending model was used to test damping capacity, in the upper and lower surface of sample there exist compressive stress and tensile stress respectively. During damping test, the imposed stress will lead to overlay effect. The magnetic domain structure will saturate at lower strain amplitude ε_max and the maximum damping capacity Q^-1_max is higher.

The microstructure evolution and the mechanical properties are presented in the drawing process of A6 aluminum conductor in this paper. The results show that the tensile strength of A6 aluminum conductor shows three-stage changes in the drawing process. In the case of extrusion deformation, grains were elongated in the drawing direction and <111> fiber texture formed. In the I-stage, aluminum conductor was strengthened by the obvious increase of dislocations. Heavy deformation led to the formation of texture in the aluminum conductor in the drawing process, which caused the further improvement of the tensile strength in the III-stage. The tensile fracture of A6 aluminum conductor exhibits ductile fracture with dimples. The strength variation in combination with the microstructure in the drawing process of A6 aluminum conductor was also discussed.

A series of three point bending tests of 960 MPa high- strength steel at low temperature were carried out in the present study, five temperature points were selected for the tests, and the crack tip opening displacement was taken as the fracture toughness index. The fracture behavior of butt weld of 960 MPa steel were analyzed based on the experimental phenomenon, the relationship between fracture toughness and temperature was investigated and the test data were fitted by the Boltzmann function, and the fracture micro mechanism was analyzed by electron microscope scanning. The results show that the variation trend of fracture toughness (critical CTOD valuesδ_m) is decline as temperature decreases, theδ_m values of 960 MPa steel are lower than that of Q235, Q345, Q390 and Q460 steels, and theδ_m values of the HAZ are lower than that for base material and weld metal, and the ductile-brittle transition temperature for HAZ(-12.45℃) is higher than that for base material and weld metal as well.

N-doped TiO₂ was prepared by the quick polymerization of Tetrabutyltitanate and phenolic resin with solvent thermal reactions using tetrabutyltitanate, phenolic resin, absolute ethanol, acetic acid, guanidine hydrochloride (GHC) and P123. The N- doped TiO₂ was characterized by XRD, SEM, TEM, XPS, N₂ adsorption-desorption and UV-Vis. We also investigated the effect of GHC adding amount to the photocatalytic activity by taking 4- aminobenzenesulfonic acid as a model test. The results showed that the N-doped TiO₂ was composed of anatase phase with a particle size about 13.7 nm and the aggregate about 100 nm. There were lots of mesoporous between the particles. The doping of N element resulted in a red shift of the absorption edge. The absorption of visible light and photocatalytic activity of N-doped TiO₂ are promoted with the increase of the adding amount of nitrogen source.The result was consistent with the atom fraction in N-TiO₂ measured by XPS.

Well-aligned TiO₂ nanotube arrays were prepared in aqueous hydrofluoric acid electrolyte by anodization in this paper. The morphology and composition of TiO₂ nanotube arrays were characterized by field emission scanning electron microscopy and X-ray photoelectron spectroscopy, respectively, the field emission performance of TiO₂ nanotube arrays was measured by field emission testing system, and the effects of pH value of electrolyte on the morphology (length and diameter) of TiO₂ nanotube arrays were investigated. The results showed that the field emission properties of TiO₂ nanotube arrays were improved due to the change of the morphology by adjusting the pH value of electrolyte. When the pH value of electrolyte was 2.0, the anodized TiO₂ nanotube arrays had the lowest turn-on field as 2.52 V/μm and a stable emission current.

The effect of cooling rate on exfoliation corrosion of Al-Zn-Mg-Cu alloy thick plate was investigated by polarization curve test, corrosion immersion test and end quench method. The results show that with cooling rate deceasing, the resistance to exfoliation corrosion decreased, from EB to ED, the corrosion potential decreased, the corrosion current density increased, and the polarization resistance decreased. There is a linear relationship between polarization resistance and cooling rate. The decreasing of cooling rate results in the higher coverage ratio and lower copper content of the grain boundary precipitates, wider precipitate free zone near grain boundaries, which are the primarily responsible for lower resistance to exfoliation corrosion.

The effects of ultrasound agitation (100 W, 100 kHz) on the structure, morphology and properties of electrodeposited Co-Ni alloy coatings were investigated in this paper. The result shows that: when ultrasonic agitation was used during the alloy coating electrodeposition, the concentration diffusion was effectively reduced, and the electron transfer between the cathode/solution interface was also promoted. Ultrasound agitation leads to the increase of Co content in alloy coating. The Co-Ni alloy coating deposited under ultrasound agitation is more fine-grained and uniform. The ultrasound agitation can lead to the enhancement of hardness and corrosion resistance properties of Co-Ni alloy coatings.

At the temperature range of 650-1050℃, the mechanical properties of steel 20CrMnTi at columnar zone, including the strain vs. stress curve, strength at high temperature, hardening coefficient and hot ductility, have been examined by applying hot tension test performed on Gleeble-1500D. The relations between mechanical property and machined position were investigated. The results show that the tensile stress decreases with increasing the distance, while hardening coefficient increases apparently at low temperature(650℃); the minimum of reduction of area for specimen 1#, 2# and 3# is about 60% at 750℃; the width of embrittlement zone is steady at 150℃when the sample changes from 1# to 3# gradually, while the temperature area moves down by 17℃. From the results of 1#, the surface temperature should be controlled above 825℃during unbending operation.

The composite 20%WC+Ni and 5%G+20%WC+Ni coatings were prepared by vacuum cladding method on the ZG45 substrate. Microstructures, forming mechanism for the coatings and the tribological properties were investigated. The results show that the microstructure of composite coating is dense, and there are not any inclusion and pores at the interface of the coating and substrate. The main composition of coating is Ni- based solid solution and hard intermetalic compounds. The major influential factor of the isomeric microstructure is the directional solidification during metal solidification. The wear results show that the friction coefficient and fluctuation of friction coefficient of 5%G + 20%WC+ Ni coating are lower than that of 20%WC + Ni coating for the same wearing testing parameters. The wear rate of 20%WC + Ni coating increases with the increasing wear frequency, whereas the wear rate of 5%G + 20%WC + Ni coating decreases with the increasing wear frequency. The abrasive wear and oxidation wear dominate the wearing process of 20%WC + Ni coating, and the oxidation wear and micro-crack lamellar for 5%G+20%WC+Ni coating.

7A52 aluminum alloy was welded using traditional ER5356 welding wire and 5356 welding wire containing Sc、Zr、Er with the method of TIG welding. The effects of Sc, Zr and Er on Mechanical properties of welded joint were investigated. The results show that the additions of Sc, Zr and Er in ER5356 welding wire resulted in the finer grains significantly and increase of the strength of the welded joint. The best effect was achieved with the addition of Sc independently. The tensile strength of welded joints is 322.5 MPa, and the strength coefficient of welded joints is 70.4% of base material.

The microstructure of broadloom AZ31B magnesium alloy roll-casting plate and its influence on the edge crack and mechanical properties of the plate were studied by using metallographic observation, SEM and mechanical property testing experiment. The results show that: the plate organization is mainly composed of α -Mg matrix, β -Mg₁₇Al₁₂ phase and α + β divorced eutectic, showing dendritic morphology; In surface and edge of the plate, β -Mg₁₇Al₁₂ phase is mainly distributed at the grain boundary and the density is bigger, formed net-shape; In center and central of the plate, spherical β -Mg₁₇Al₁₂ phase is dispersed in α-Mg matrix, formed lamellar-shape; The main reason for the edge crack in the cast-rolling process is in the slab edge interdendritic low-melting eutectic phase and β -Mg₁₇Al₁₂ phase of grain boundary which are easy to be crack source, and extend outward along the crystal; The tensile specimen showes brittle cleavage fracture characteristics, and its mechanical property is obvious anisotropy.

A TiC/Ni₃Al intermetallic matrix composite coating was fabricated on a steel by gas tungsten arc welding. The microstructure and properties of the coating were investigated. The formation mechanism and erosive wear mechanism of the coating were also discussed. The results show that TiC/Ni3Al coating formed on the steel without any intermediate phases and the distribution of TiC particles is homogeneous. The hardness and the number of particles of the coating increased with increasing (Ti+C) content in the preform. The interface between the coating and steel substrate has a good metallurgical bonding. The morphology of TiC particles changed from fine spherical to equiaxial and then to dendritic shape. From the coating surface to the interface, the distributions of Al, Ni, and Fe are gradual variation. However, Ti exists in the coating in the form of TiC particle. The composite coating has obviously lower mass loss than that of H13 and 0Cr13Ni5Mo steels at any impact angle, showing superior erosion resistance.

The microcrystalline silicon films were deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD) using SiH₄/Ar and SiH₄/H₂ gaseous mixture. The effects of dilute gas on deposition rate, crystallinity, grain size and the configuration of H existing in microcrystalline silicon films were investigated. The results show that the deposition rate of the film using Ar as discharge gas is 1.5-2 times higher than that using H₂, but the film crystallinity is lower. At the same time, the concentration of hydrogen in the films deposited using SiH₄/Ar is less than that of using SiH₄/H₂, but the preferred orientations and the grain sizes of the films are analogous.

TiC_0.81N_0.48 coating and TiC_0.61N_0.44O_0.15 coating deposited by medium temperature chemical vapor deposition, were characterized by Vickers hardness tester, X-ray diffraction (XRD) and confocal Raman spectrometer, and the effect of microstructure transformation on the hardness was investigated. Results show that the hardness of TiC_0.81N_0.48 and TiC_0.61N_0.44O_0.15 coatings declines after annealing at 700 ℃ in vacuum, and then tends to be stable. At the beginning of the annealing, some C atoms escape from the lattice of TiCN, resulting in the formation of sp³C. As the annealing time prolongs, sp³C transforms to sp²C gradually. Thereafter the clustering of sp²C increases, the disorder degree decreases, and TiCN decomposes into TiC and TiN. The decrease of hardness is related with the release of residual stress due to the defect annihilation. Besides, the microstructure transformation especially the formation of sp³C and sp²C decreases the hardness of coatings. Compared with TiC_0.61N_0.44O_0.15, the microstructure transformation takes places earlier in TiC_0.81N_0.48 coating, which exhibits worse thermal stability.

The microstructure and mechanical properties in different extrusion directions of Mg-9.8Gd-1.6Y-0.02Zn-0.5Zr(GW102 alloy) bar were investigated by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM).The results show that the microstructure of GW102 alloy mainly consist of supersaturated solid solution, a few particle Mg₅(Y_0.6Gd_0.4) phase and non-equilibrium phases Mg₃(Gd_0.5, Y_0.5).The β″ and β′ phases formed after aging treatment at 200 ℃ for 60 h. The anisotropy is obvious in this magnesium alloy. The tensile strength and elongation in vertical direction of extrusion state after aging treatment was significantly lower than that in extrusion direction at room temperature. The interaction of LPSO and dislocations and the precipitates-free zone(PFZ) appeared in the grain boundary were investigated, whose influence on mechanical properties of GW102 alloy was discussed.

The effects of yttrium with different content on the microstructures and mechanical properties of intermetallic compound Mg₁₇Al ₁₂ were investigated by using scanning electron microscope(SEM), Xray diffractometer(XRD), electronic universal testing machines and electrochemical method.The results show that proper content of Y can refine the microstructures of intermetallic compound Mg₁₇Al ₁₂, and a new irregular phase Al₂Y and a renju shaped phase eutectic structureα-Mg+β-Mg₁₇Al ₁₂ form. The proper content of Y can improve the intermetallic compound Mg₁₇Al ₁₂’s corrosion resistance and mechanical properties at room temperature. The alloy has the best properties when the content of the Y is 2.0% ,however excessive Y decreases the combination properties of the intermetallic compound.

Quenching cooling at different radius positions of large-scale steam turbine rotor were simulated by air-cooling heat treatment furnace. The effects of quenching cooling rate on microstructure, strength and toughness of 30CrMoNiV511 rotor steel were investigated. The results show that the cooling rate has a little influence on the strength, while the toughness evidently depends on it. As the cooling rate decrease gradually from 50 ℃/min to 7 ^oC/min, and the transformed microstructure changes from low bainite to upper bainite, granular bainite and their mixture. Meanwhile, impact toughness decreases sharply from 66 J to 16 J. When the cooling rate is below 5 ℃/min, proeutectoid ferrite is formed. The sub-unit of ferrite in upper bainite is coarse with uneven distribution of carbides, which results in extremely low toughness. The microstructure and carbides shape and distribution depending on the quenching cooling rate is one of the main reasons determining the impact toughness of rotor steel.