Advanced Materials Research Vols. 415-417

Abstract: Mn-doped ZnO nanorod arrays (ZnO:Mn NAs) have been prepared by a solution deposition method and the effect of Mn modification has been studied. Microstructure, morphology, photoluminescence characteristics of the ZnO: Mn NAs were investigated using X-ray diffraction, field emission scanning electron microscopy, fourier transform infrared spectrometer, fluorescence spectrophotometer. XRD analysis shows that ZnO:Mn NAs are wurtzite phases and highly c-axis oriented. As for ZnO:Mn NAs, obvious changes of photoluminescence intensity are observed at the wavelength of 395nm and 550 nm, according to Mn/Zn atomic ratio.

Abstract: Slag corrosion resistance behavior of MgO-ZrO₂ refractory was investigated in this work. The results indicated that in the non-oriented electric steel slag system with a high ratio of calcia to silica, the slag resistance behavior of MgO-ZrO₂ composite could be described as follows: the ZrO₂ reacts with CaO forming the calcium zirconate compound which is densification encapsulating periclase lay. However, in the oriented electric steel slag system with a high concentration of silica and the low ratio value of calcia to silica, the slag corrosion resistance behavior of MgO-ZrO₂ composite is different. The ZrO₂ would react with CaO forming the calcium zirconate and simultaneously, one more product C₂S as well. C₂S has double response of strength and could increase corrosion resistance performance by blinding pore and thickening slag viscosity. Therefore, it is expected to be the major reason for the enhanced corrosion resistance behavior observed for MgO-ZrO₂ refractory.

Abstract: The experiments of thermal fatigue damage on piston were conducted by shaped high power laser. Microstructure of thermal fatigue damaged specimen was characterized by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The mechanical properties of thermal fatigue specimen were evaluated by microhardness and the corresponding damaged mechanisms were discussed. The results show that cracks originated from the interface of Al-matrix and intermetallic phase due to the thermal and mechanical mismatch between the brittle components of the microstructure and the surrounding ductile matrix. Oxides of thermal fatigue crack can accelerate the damage of piston. There exists a decline tendency in the microhardness of piston at all locations after thermal fatigue tests due to the comprehensive effects of nonequilibrium distribution of temperature and cooling method.

Abstract: Effects of Ce addition on the microstructures and mechanical properties of the Ni-Co-based superalloy were investigated. The results showed that addition of Ce to the alloys resulted in a Ce-rich phase (Ni,Co)₃Ce formation. The rupture life was improved greatly by Ce addition and the optimal Ce addition was about 0.2 wt.%. Both peak stress and critical stress of dynamic recrystallization were increased with increasing (Ni,Co)₃Ce phases, which was mainly due to pinning effect on grain boundary sliding by precipitation.

Abstract: In order to ensure long lifetime and stable light output of LEDs the thermal performance parameters need to be designed in the LED chip package and module level, which include such items as heat sink structure and materials, interface materials and substrates. In this work we used aluminium nitride(AlN) as submount of LED chips and made chip on board(COB) type LED module. The effect of different silver(Ag) epoxy bonding materials and bonding methods on the performance of LED module were examined. The effect of addition of red quantum dot(QD) on the performance of white LED was also studied.

Abstract: The various methods for improving chloride penetration resistance in the reinforced concrete have been developed. Among the related general ways, using of corrosion inhibitor became very common. Therefore, in this study, in order to comprehend performance of corrosion inhibitor, the experiment study was conducted about corrosion characteristic of 3 steps(0.0, norm 1/2, norm) compared to organic corrosion inhibitor standard use of liquid and molar 3 steps(0.0, 0.3, 0.6%) of Chloride by added amount of inorganic corrosion inhibitor by the corrosion inhibitor types about 2.4kg/m³, 4.8kg/m³ based on Chloride ion content 1.2kg/m³ for service life prediction of concrete structure by using Poteniostat. As results, in the case of inorganic nitrous acid corrosion inhibitor, it was confirmed that anti-corrosive performance of Chloride ion content 1.2kg/m³ by corrosion Ecorr -0.30V in more than molar ratio 0.3%, and it also was confirmed that anti-corrosive performance of 2.4kg/m³, 4.8kg/m³ in more than molar ratio 0.6%. In addition, the excellent anti-corrosive performance of organic corrosion inhibitor was shown in 1/2(0.42kg/m³) of norm regardless of Chloride ion content, and it can be seen that absorption types organic corrosion inhibitor has excellent anti-corrosive performance compared to the inorganic nitrous acid corrosion inhibitor by the added amount of corrosion inhibitor.

Abstract: Corrosion sensors were devised to develop a system whereby the depth of chloride permeation from concrete surfaces can be monitored in cover concrete of reinforced concrete structures. For making sensor which is similar to rebar author uses Screen printer machines, Ag paste and Fe powder. Appropriate portion of Ag and Fe is over 1:2. The resistance of sensors increased as the degree of corrosion increased.

Abstract: This paper investigate the mechanical property and microstructure of girth weldment of Lan Zhou to Cheng Du crude oil pipeline. The welding joint was bottomed by cellulose electrode E6010 and filled and covered by flux-cored wire AWS A 5.29 E71T8-Ni1. According to SY/T 4103-2006, test results show that the selected process parameters and welding method take on outstanding performance .Microstructure of weld joints is acicular ferrite, polygonal ferrite, proeutectoid ferrite and granular bainite, and widmanstaten ferrite dosn’t exsist in heat affected zone(HAZ). Microstrure of the whole weld joint is mainly polygonal ferrite and granular bainite, this is the reason that mechanical properties can meet the Lan Zhou to Cheng Du crude oil pipeline project requirement.

Abstract: This paper introduces the explosion-protection performance of a kind of meshy aluminum alloy material in different blank rates and different packed densities. Experiment results show that this material has the best explosion-protection effect when the packed density between 30~35 kg/m³. When the packed density is fixed the pressure increase quickly with the increase of blank rate, the flame becomes smaller after filled with the material so this material can decrease the spread of flame. Besides we get the empirical equation of the packed density, blank rate and pressure.

Abstract: Making use of the low energy electron beam produced by the accelerator of Dynamitron which has 1-3 Mev energy and 90KW maximum power, GaN based blue LED is proceed by the electron beam irradiation. The color and luminosity parameter of the irradiated LED are contrasted with the unirradiated LED. The experimental result is analyzed and discussed. The results show that the dominant wavelength is shifted, the color purity is improved, the flux and the optical efficiency are dreased by the electron beam irradiation. We also find that the displacement of atoms in LED quantum well, the non-complex compound and minority carrier lifetime is reduced by the electron beam irradiation.