Advanced Materials Research Vol. 842

Abstract: ZrO₂ support has been prepared by sol-gel and coprecipitation method. CuO and NiO were supported on the supports and they were the activity metals for the catalysts. The CO conversion was tested. The light-off temperature of CO oxidation was 22°C and CO conversion efficiency was up to 50% at 169°C. The prepared catalysts of Cu, Ni supported on ZrO₂-A had a high activity for CO oxidation at low temperature.

Abstract: Three-phase light-weight CNTs/Fe₃O₄/PANI nanocomposites were prepared by the co-precipitation of Fe²⁺ and Fe³⁺,and a quick process of in situ polymerization of aniline monomer. The structure and morphology of CNTs /Fe₃O₄/ PANI were characterized by transmission electron-microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and fourier transform infrared (FTIR) spectroscopy. The CNTs/Fe₃O₄/PANI nanocomposites exhibit less intertwined structure and that many more Fe₃O₄ particles are attached homogeneously on the surface of CNTs, indicating that PANI can indeed help CNTs to disperse in isolated form. The wave absorbing properties were investigated in a frequency of 218 GHz. The results show that the CNTs/Fe₃O₄/PANI nanocomposites exhibit a super absorbing behavior and possess a maximum reflection loss of 48 dB at 12.9 GHz, and the bandwidth below 20 dB is more than 5 GHz.

Abstract: In this paper surface modification was adopted on 3 kinds of titanium alloy and TiO₂ nanotubes arrays were prepared on these surfaces by anodic oxidation method.nanoindentation and nanoscratch experiments were performed to test the mechanical properties of TiO₂ film, such as micro hardness and elastic modulus.Through comparing and analyzing,it is seen that,The film generated on the TC4 has better mechanical properties than the others and TC4 is better substrate for surface modification by anodic oxidation as the implanted materials.

Abstract: LiMn_0.75Ti_0.5O₃ was prepared by a solid state reaction crystallization method. The acid treatments of LiMn_0.75Ti_0.5O₃ caused Li²⁺ extractions of more than 75%, while the dissolutions of Mn⁴⁺ and Ti⁴⁺ were less than 13%. The experimental results have proved that the acid-treated sample has a capacity of exchange 4.1mmol·g-1 for Li⁺ in the solution.

Abstract: Compound [Li_0.5Mn_1.375O₃] was a spinel-type metal compound and was prepared by a solid state reaction crystallization method. The results showed that the Li⁺ extraction/insertion be progressed mainly by an ion-exchange mechanism. The characterization results showed that the exchange capacity of Li⁺ was 2.8mmol/g for Li⁺. Li_0.5Mn_1.375O₃ is an ion-memory inorganic ion exchanger of Li⁺. It had a memorial ion-sieve property for Li⁺.

Abstract: [LiMn_1.25O₃] was prepared by a solid state reaction crystallization method. And it was a spinel-type metal compound. The solid state reaction with this material was investigation by X-ray, saturation capacity of exchange, and Kd measurement. The results showed that the Li⁺ extraction/insertion be progressed mainly by an ion-exchange mechanism. The acid treated samples had an ion exchange capacity of 4.0mmol/g for Li⁺.

Abstract: The investigation was carried out to study the effect of a novel process of surface modification, surface nanocrystallization by high energy shot peening (HESP), on osteoblast proliferation and differentiation. A disc of pure titanium was processed to HESP in a commercial shot peening equipment, to create nanostructure at the surface. The surface microstructure was characterized by SEM and osteoblasts were co-cultured with the surface nanostructured titanium and unreceived titanium surface to evaluate their biocompatibility. The nanostructured surface layer on titanium was successfully processed by HESP, and the nanosized grains were about 60 nm in diameter and inhomogeneous distributed on the surface of n-Ti. The results also confirmed the proliferation and differentiation of osteoblasts were highly improved on surface nanostructured titanium. This finding suggests that there is high potential of this novel surface modification process which could enhance bone tissue growth of dental implant.

Abstract: The adhesive cure reaction in manufacture of ferrite phase shifter is studied. Strength of epoxy adhesive joint has been tested in process experiments. Mathematical model is fitted to describe the relationship between the strength of adhesive joint and curing pressure, and an appropriate curing pressure is obtained through sensitivity analysis. The real-time control scheme of process parameters is carried out to improve the first pass rate, which is influenced by void defects in the adhesive layer.

Abstract: The effect of artificial aging on the corrosion properties of 6063 Al alloy was investigated by optical microscope, field emission scanning electron microscope and accelerated corrosion test. Accelerated corrosion test revealed that the alloy was susceptible to intergranular corrosion (IGC) in the artificial aged conditions according to the surface corrosion morphology, and the IGC resistance was reduced as the aging time was prolonged, resulting from more Mg₂Si grain boundary precipitates formed. However, the corroded cross-sections showed that the IGC was very local. Additionally, the surface corrosion morphology also showed that pitting corrosion took place, resulting from galvanic corrosion between (FeMn)₃Si₁₂Al₁₅ particles and matrix Al.

Abstract: The influences of different pulse voltage, discharging frequency, pouring temperature and mold temperature on marostructure of Mg₉₇Y₂Cu₁ alloy under pulsed direct current magnetic field (PDCMF) were studied and the related mechanism was also discussed. The results show that grains of Mg₉₇Y₂Cu₁ alloy can be refined greatly by PDCMF treatment. Macrostructure of the alloy is changed from coarsened grains to complete fine equiaxed grains. When the pulse voltage is at 0-250V, grain size of the alloy decreases dramatically as pulse voltage increases. When the discharging frequency is at 1-10Hz, grain size of the alloy increases firstly, then decreases, and the turning point is 5 Hz. The change of grain size is not obvious, when the discharging frequency increases from 1 Hz to 5 Hz. When the discharging frequency reaches 10 Hz, the effect of grain refinement is the best. When the mold temperature is at 20-600°C or the pouring temperature is at 660-750°C, grain size of the alloy with PDCMF treatment decreases grossly with the increase of the mold temperature or the pouring temperature. The higher the pouring temperature or the mold temperature, the better the effect of grain refinement with PDCMF treatment.