Advanced Materials Research Vols. 581-582

Abstract: Foam glasses were prepared using borosilicate tube glass cullet along with commercial CaCO3 and H3BO3. The influence of relative content of CaCO3 and H3BO3 on the apparent density, volume and pore size was evaluated. The results show that homogenous microstructures of large pores with the average diameter of 1.0 mm can be obtained by adding small amount of CaCO3 with the aid of 3.0 wt% H3BO3.On the other hand, the foaming effect of CaCO3 is greatly enhanced with increasing H3BO3. However, excess CaCO3 leads to increase of apparent density and decrease of pore size, and the relevant mechanism is discussed.

Abstract: The melt-spinning technique is used to fabricate the Mg20Ni9M1 (M=Cu, Co) alloys with nanocrystalline and amorphous structure. The microstructures of the as-spun alloys were characterized by XRD and TEM. The electrochemical hydrogen storage properties of the alloys were measured. The results show that the as-spun (M=Cu) alloys hold an entire nanocrystalline structure and small amount of amorphous phase is visible on the grain boundaries of the as-spun (M=Co) alloy. The discharge capacity and high rate discharge ability (HRD) of the alloys visibly grow with the rising of the spinning rate. The action of the melt spinning on the cycle stability of the alloys is associated with substitution element. For M=Cu, the capacity retaining rate (SN) evidently falls with the growing of the spinning rate; whereas for M=Co, it first declines and then augments.

Abstract: Keywords: Hot-Dip Aluminum; Corrosion resistance; Fe-Al Intermetallic alloys Abstract. The hot-dipping Al coating was developed on 22MnB5 steel surface. Effects of corrosion resistance with different dipping time coatings were investigated in this paper. It is describes an approach to improve the corrosion resistance of 22MnB5 steel. The results of the polarization curves show that the dipping 2min coatings have the highest corrosion potential (Ecorr) and the lowest corrosion current (icorr), indicating that this coating is a best corrosion inhibitor. It is similar results with EIS for corrosion resistance, respectively. The proper thickness (~20µm) of Fe-Al compounds between Fe substrate and Al coatings must be selected (750°C, hot-dipping 2min) in order to improve corrosion resistance for 22MnB5 steel.

Abstract: The microstructure evolution of Ni-45Ti-5Al(atomic fraction, %) alloys prepared by directional solidification with liquid-metal-cooling at different temperatures of 1450°C, 1550°C and 1650°C was investigated. The results showed that the macrostructure in directional solidification growth region was obvious columnar grains. The microstructure was cellular growth structure, and composed of primary NiTi matrix and Ti2Ni precipitates. The preferred orientation of NiTi and Ti2Ni were respectively [100] and [111] direction. It was found that aluminum was dissolved in both NiTi and Ti2Ni phase. The Al content in the matrix was higher than it in the precipitates. As heating temperature increasing, the microstructure evolution was inconspicuous and the average cellular spacing was 30~50μm. The Ti2Ni volume percent was most when the heating temperature was 1550°C.

Abstract: ZnO nanoparticles with high surface area were synthesized by hydrothermal homogeneous precipitation method, and the influences of physicochemical properties of ZnO materials on the adsorptive desulfurization performance of Ni/ZnO adsorbent were investigated. Activity evaluation showed that the Ni/ZnO adsorbent using nanosize ZnO as support materials had better adsorption performance, and the sulfur adsorption capacity was maximized depending on the surface area and particle size of ZnO materials. The thiophene removal efficiency and the breakthrough capacity (10 ppm level) were found to be 100% and 6.1 (mg of sulfur per g of adsorbent), respectively.

Abstract: Black micro-arc oxidation (MAO) ceramic coatings were prepared on magnesium alloy in a silicate electrolyte; SEM, EDS and XRD were tested to analyze surface morphology, chemical composition and phase composition of ceramic coatings, Corrosion resistant in 3.5％ NaCl aqueous solution of magnesium alloy before and after MAO treatment was evaluated by polarization curves and electrochemical impedance spectroscopy (EIS); the weight loss of magnesium alloy with black MAO ceramic coatings in 3.5％ NaCl aqueous solution was studied through immersion experiment. The results indicated that, the black MAO ceramic coatings was composed by Mg、Al、Si、Cu and O; black MAO ceramic coatings could protect magnesium alloy substrate effectively; the corrosion resistant of black MAO ceramic coatings in neutral 3.5% NaCl solution was favorable.

Abstract: _{Subscript text} Nd can obviously improve the mechanical properties of spray deposited 1%Nd, 2%Nd extruded and heat treatment alloy. Nd solid solution in α-Mg matrix lead to the hardness of 2%Nd spray deposited magnesium alloy extruded is higher than that of after heat treatment. A large number of Al₂Nd particles precipitation is the key factor to the highest hardness value(139.4Hv) in 2%Nd magnesium alloy after 370°C/3h+205°C/24h heat treatment. Moreover, the precipitation of Al₂Nd accompany with Al₂Ca and Al-Mn phase increased.

Abstract: The casting and solution microstructure of Cu-7.5Ni-5.0Sn alloy were studied.The results showed that the cast Cu-7.5Ni-5.0Sn alloy existed serious dendritic. The microstructure of the cast Cu-7.5Ni-5.0Sn alloy is divided into three parts, namely, gray dendritic (α phase, ie, Cu-Ni solid solution), interdendritic white bright objects or bone-like organization ((CuX、Ni1-X)3Sn phase, ie, γ phase), dark gray organization of the transition between the dendrite and the bone-like organization (α phase and γ phase mixture). Solution temperature will affect the solid solution effects. The best solution condition is heated at 800°C for 1h. Subsequently, the alloy cold rolling deformation is up to 50%.

Abstract: The binary Ni-rich Ni64Al36 (nominal compositions, all compositions are in atomic percent unless otherwise stated,) alloy and ternary Ni-21.2 Al-20 Fe alloy ingot were prepared by melting commercial pure Ni and pure Al in a vacuum arc furnace under an argon atmosphere. The ingots were then hot rolled into a rectangle with the length of 55 mm. The microstructures of Ni-Al-based alloys were investigated using optical microscope and X-ray diffraction. The damping capacity of oil-quenched ternary Ni-21.2 Al-20 Fe alloy from different temperature is investigated using a multifunctional internal friction apparatus.