Applied Mechanics and Materials Vols. 303-306

Abstract: Lathanum hexaboride films were deposited by dc magnetron sputtering with the same sputtering parameters. AFM, XRD, Raman spectrum was used to characterize the film. The as-deposited films were annealed at 400 ^oC, 500 ^oC and 600 ^oC, respectively. After 400 oC’s annealing, morphology of fracture cross-sections of the films exhibited evolutions from columnar to the equiaxial, and the crystallinity of the film was improved as well. It was also found annealing process generated negative effect on the film’s hardness and elastic modulus.

Abstract: A series of Si (100) based LaB₆ films were deposited by D.C. magnetron sputtering with different argon pressure, one of the most important deposition parameters, which affect both the structure and properties of the thin films. XRD, AFM, Raman, and Hall measuring instrument were used to characterize the film structure and performances. It was found that argon pressure strongly influenced the condensing particles’ kinetic energy obviously through affecting the scattering processes of sputtered energetic particles, which played a crucial role in the growth of the LaB₆ films. LaB₆ film deposited at 1.0 Pa showed a higher crystallinity degree. Morever, the film displayed a more uniform structure and better electrical property, the relationship between microsture, electrical property and crystallinity were demonstrted as well.

Abstract: The microstructure of magnesium alloy sheets (nominal composition Mg–6Zn–Y in at. %) was investigated with the Optical Microscope (OM), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) technique after the annealing treatment. Tensile test at room temperature was performed to show the influence of annealing treatment on mechanical properties. Experimental results indicate that there are a large number of twin crystals appearing in microstructure of the extruded Mg-Zn-Y alloy sheet at 350 °C. The distinct icosahedral phase appears on the α-Mg matrix in granular form and the strength gets largely improved to the maximum. The uniform distribution of isometric crystal contributes to the best elongation at the annealing temperature of 400 °C.

Abstract: Based on studying of ore property and tests, the suitable mineral processing flowsheet for the tin—iron ore had been determined. Better technical and economic indexes had been achieved: the iron concentrate grade reached 64.45%, and the tin concentrate grade reached 13.06%. It gave a technical reference to rational development and utilization of such kind of tin-iron ore resource.

Abstract: This paper represents the improvement of method for determination of isocyanate group content in polyurethane prepolymer. Acetone-dibutylamine method and toluene-dibutylamine method were used separately to determine the isocyanate group content in polyurethane prepolymer. The –NCO content tested by the two methods were close. In the former method, 15-20 mL acetone was used as solvent and the titration end point was easy to confirm. While in the latter method, additional solvent (isopropanol) was used which causes environmental contamination.

Abstract: The fine oolitic hematite ore (<20µm) is easily covered by the ore slime, therefore, it is processed very difficultly with traditional crafts, for example, gravity treatment, magnetic separation, and flotation. The tiny iron ore is unable to recycle effectively, bring about a large of useful minerals running off. It is indicated that the selective flocculation is effective separation craft in many research works. The good dispersion of fine particles is the selective flocculation essential condition, the excessive dispersion will destroy the selective flocculation, at the same time it can be influenced by the water quality, pH, the mixing time, the shear rate and the dispersing agent dosage. In this paper, to oolitic hematite ore, the chemistry dispersion research is conducted to provide the foundation for further selective flocculation separation.

Abstract: According to the nature of the ore which containing hematite and magnetite,under the conditions,for example,ore grade is 24.07%,the first fineness of grinding -200 mesh is 50%，the second fineness of grinding -200 mesh is more than 95%, it is concluded that concentrating circuit consisting of first grind-Feebleness magnetic separation -high intensity magnetic separation，second grind-second-high intensity magnetic separation-shaking tables. Ultimately, A concentrate with a productivity of 19.35%，a grade of 65.89% TFe and the recovery of 52.32%was yielded.

Abstract: The corrosion of fasteners in ballast tank is much serious, due to the wet-dry corrosive conditions. Now most fasteners are protected by zinc-aluminium coating. In order to evaluate the anticorrosion performance of hot dip Galvanized (GI), Galfan (GF) and Galvalume (GL) coated fasteners in wet-dry cyclic conditions, the corrosion behavior of these coatings in 1h wet and 7h drying condition were investigated by electrochemical impedance spectroscopy technology. The corrosion rate of GI coating in drying condition is much faster than that in wet condition before 23rd cycle, after that time the corrosion rate in sea water is faster than that in drying condition, however the corrosion rate of GF coatings in drying condition is much slower than that in wet condition, and for GL coating, the polarization resistance is both than 104Ω•cm2, whether it is immersed in seawater or in drying condition, which suggests it has better anticorrosion performance. The corrosion rate of the GI, GF and GL coating is 30µm per year, 1.5µm per year and 1.3µm per year respectively and corrosion resistance of GL and GF is therefore twenty two and twenty times as that of GI.

Abstract: Microscopic structure and mineral composition of shallow rock in different geological group were detect using scanning electron microscopy technology, and the influence of microscopic structure and mineral composition on macro-mechanical properties was analyzed. The results showed that: from the surface to the coal seam: sandy mudstone particle surface banded, non-directional distribution into flake orientation distribution point - point contact - surface contact into contact between particles, resulting in the rock mass more easily broken, the breaking the block becomes small; the sandy mudstone particle volume decreases, the smaller the gap between the particles, and by filling into velvet spherical aggregates filling, resulting in increased contact area in the rock mass fracture; sandy shale montmorillonite content increases, the rock mass in the water particle volume expansion, extrusion intergranular pore, reduce pore channel, the rock mass macroscopic pass water to reduce.

Abstract: his template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. Please make the page settings of your word processor to A4 format (21 x 29,7 cm or 8 x 11 inches); with the margins: Comments on technology progress of hematite processing,and introduce the hematite mineral processing technology, put forward the development direction of hematite precessing.