Advanced Materials Research Vols. 602-604

Abstract: To accurately control the Si content and ensure the function of slag refining in high aluminum steel, the direction and limits of reduction reaction for SiO2 were analyzed based on the thermodynamics. In addition, the thermodynamic prediction model of multi-element slag was studied. Then, a slag activity prediction model was established based on the coexistence theory. Using the model, the suitable ladle slag composition for high aluminum steel was calculated.

Abstract: This paper investigates the improvement of the toughness of UHPC through the use of conventional straight steel fibers and twisted fibers. The conventional straight steel fiber has length of 13 mm and diameter of 0.2 mm. Besides, twisted fibers with diameters of 0.2 mm, 0.22 mm and 0.3 mm, respective lengths of 20 mm, 22 mm and 30 mm and made of high elastic steel fibers with aspect ratio (l/d) of 100 are used at volume fractions of 1%, 1.5% and 2%. The results of the examination of the direct tensile behavior reveal the occurrence of strain hardening after early cracking. K-UHPC using twisted fiber exhibits significantly improved mechanical characteristics compared to UHPC using conventional straight fiber. Equivalent or superior performance is developed when small proportion of about 0.5% of steel fiber is adopted and 90% of the performance is developed when small proportion of approximately 1.0% of fiber is admixed. Consequently, the use of twisted fiber in K-UHPC opens the possibility to achieve economically efficient fabrication by enabling significant reduction of the amount of fiber.

Abstract: Novel high near-infrared reflecting inorganic pigments Y_6-xSm_xMoO_12+σ (03+ in yttrium molybdate through a simple solid-state reaction method. The composites were characterized using scanning electron microscope, X-ray diffraction, UV-vis-NIR spectrophotometer and CIE 1976 L^*a^*b^* color scales. The substitution of Sm³⁺ for Y³⁺ in Y₆MoO₁₂ changed the color from bright yellow to dark yellow and most importantly increased near-infrared reflectance in the wavelength range of 700-2500 nm. The chemical stability of the pigments was also evaluated.

Abstract: AlN-ZrO₂ system composites were prepared with Ca-stabilized zirconia (Ca-PSZ, particle size d₅₀=29.3 μm) and AlN power (d₅₀=0.5 μm) as raw material, MoSi₂ (d₅₀=2 μm) and Si₃N₄ (d₅₀=44 μm) as additives respectively, in N₂ atmosphere by pressureless sintering at 1600 °C. The phase compositions were investigated by XRD. The sintering performance of the composites was measured by the checking of the bending strength and the apparent porosity of samples. The anti-oxidation performance of the composites was analyzed by the checking of oxidation weight increased of samples. The results showed that phase compositions of the composites consisted of ZrO₂, ZrN, CaAl₁₂O₁₉ and CaA_l2Si₂O₈when the content of AlN was 8 wt %. The additives promoted the sintering of AlN-ZrO₂ system composites. As a result, introduction of the additives increased the oxidation of the composites due to oxidation expansion of phases ZrN.

Abstract: The stress characteristics on a composite wind turbine blade are analyzed by using a finite element method. The whole stress level of the spar cap and the blade root is higher than that of the shear web and the airfoil plate, so the spar cap and the blade root are the main force-supporting parts. If the stress concentration point on the interface corner between the blade root and the shear web is neglected, the stress of the spar cap is higher than that of the blade root, and its maximum stress and mean stress are 211 MPa and 180 MPa respectively. The maximum stress of the blade is only 34.8% of the tensile stress of the glass-fiber/epoxy composites. It indicates that the laminate structural design of the blade is inclined to be safety.

Abstract: As high-grade refractories raw material，kyanite is widely used and the market demand is increasingly greater. To identify the process mineralogical properties of kyanite from Heibei so as to provide a mineralogical basis for its chemical composition, mineral constituent，ores texture and structure and so on. The results show that: the kyanite Al2O3 21.50%, SiO2 52.87%, using high intensity magnetic separation-gravity separation-flotation folwsheet. Experiments show that, the grinding fineness of -200 mush 65%, with strong intensity magnetic separation, magnetic concentrate by shaking the low intensity magnetic separation，we can get magnetite, garnet, biotite and phlogopite four concentrates, strong magnetic ore tailings consolidated by a rocking bed mud thrown first, refined through flotation, won Kyanite concentrate grading about 56.11% at a recovery of 49.90%.

Abstract: This article analyzes the introduction of advanced materials into Wushu equipment, which provides a turning point for the development of sports equipment in national traditional sports. It helps change the traditional Wushu conditions as well as offers strong support to the development of Wushu competition and Wushu standardized development. Therefore, based on the advantage of fiber reinforced composite materials application in Wushu equipment, the application of fiber reinforced composites in Wushu instruments, clothing, protective gear and target is described.

Abstract: With the development of industrial production, kyanite's position is more and more important in social production, This paper introduces the physical and chemical characteristics of kyanite, technology characteristics，and has made the quite overview to the application of kyanite and its industry standards.

Abstract: Material wear such as abrasiveness, cavitations erosion, and grinding balls with large diameter etc, exists during the usage of ball mill lining board. The effect of the chemical contents, composite casting process and heat treatment parameter on the interface microstructure, mechanical properties and wear resistance were studied by the SEM, EDAX and TEM, etc. The results show that the bimetal interface formed an effective metallurgical bonding boundary without mixing. The impact toughness of the interface is higher than the working face. The bimetal composite lining board has a very good stability. The service life of the bimetal lining board is increased 70% than the medium carbon low alloy steel under the same service conditions and the process yielding is over 95%.

Abstract: In this paper, we designed a FGM which can be used as the cover of underwater target and research its mid-low frequency acoustic characteristic just as reflection and absorption coefficient. Based on transfer matrix method, we research the FGM acoustic reflection and absorption coefficient change with the variation of constituent material property, number of hierarchy, and volume fraction. We found that its reflection and absorption coefficient are determinated by material property and volume fraction, and could be equivalent to multi-layer composite structure with specific number of layers to address acoustic problems. If elastic layer added, both acoustic characteristic and mechanics characteristic could be improved, which contributes to the research and design of structure/acoustic stealth FGM.