Advanced Materials Research Vols. 602-604

Abstract: In the early stage of commissioning, in order to solve the problem of bad metallurgical effect and serious lining erosion during steelmaking, oxygen supply strength is improved and lance position is adjusted as well. In addition, technology of “remaining slag and charging dolomitic lime” is applied to reduce the erosion velocity of lining. Results show that metallurgical effect of BOF is better after oxygen supply strength is improved, and which ensure the high efficiency production and smooth operation of BOF.

Abstract: The high strength high plasticity high beneficial textile cold-rolling steel with 540MPa tensile strength 27% elongation 1.67 (111) textile index is developed in industry. The experimental results show that the ferrite fine grain around 5μm supports the properties of both high strength and plasticity, while the ferrite with percentage more than 90% leads to high elongation, and the large number second precipitation phase NbC with uniform fine size around 10nm is helpful to fine ferrite grain and form strong（111）textile fiber.

Abstract: Polycrystalline Pb(Mn_0.5W_0.5)O₃, PMW, a ferroelectric oxide was prepared by high temperature solid state reaction route. In order to reduce the measurement error caused by edge capacitance, laboratory-made three-terminal ring electrode (including a guard terminal) was constructed. A guard ring electrode eliminated parallel resistance paths that could cause errors in materials resistance measurements. Guard ring electrodes were useful devices which enable accurate dielectric measurements to be made on small sample of insulating material. The dielectric constant (ε′) and loss tangent (tan δ) of PMW ceramics were measured as a function of frequency ( 1 kHz- 100 kHz ). The volume resistivity and surface resistivity of PMW ceramics were also investigated. The smallest value of volume and surface resistivity were found to be 1.6 × 10-4 MΩ and 0.1281 MΩ, respectively.

Abstract: Fused quartz powder (d₅₀=19μm) was used as raw material, and nano-Nd₂O₃ was used as additive with dosages of 1% (in mass, similarly hereinafter), 2% and 3%. The effects of nano-Nd₂O₃ on crystallization and sintering behavior of the materials at various temperatures (1300 °C/1h, 1350 °C /1h and 1400°C /1h) were studied by measurements of apparent porosity, bending strength and thermal expansion ratios (RT~1200°C), and analyses of XRD and SEM. The results of XRD and thermal expansion ratios analysis showed that 3% nano-Nd₂O₃ additive had excellent effect on inhibiting crystallization of the samples sintered at 1350 °C and 1400°C. The results showed that the samples sintered at various temperatures with 3% nano-Nd2O3 had the lowest apparent porosity and more compact microstructure. This indicated that 3% nano-Nd₂O₃ had better effect on facilitating sintering of fused quartz materials.

Abstract: The processing of boron carbide by pressureless sintering with nano-sized rare-earth compounds additives to obtain dense pellets for use as neutron absorber in fast breeder reactors is investigated. The effect of dysprosium aluminum garnet (DAG) and dysprosium titanate nanopowders on density and mechanical properties was studied. The addition of DAG and dysprosium titanate nanopowders was found to be beneficial in the densification of B₄C powders. B₄C with 5 wt. % of DAG or dysprosium titanate nanopowders, exhibiting bulk density of 2.14g/cm³ and 2.35 g/cm³, could be prepared by pressureless heating at 2120°C and 2160°C.

Abstract: Synthesis process of ZrAl₃O₃N was investigated by non-pressure sintering at 1600 °C in N₂ atmosphere according to five drafted equations. The influences of the atmosphere and material combination on the synthetic effect of ZrAl₃O₃N were preliminarily discussed by XRD. The results showed that atmosphere was a key factor that determined whether ZrAl₃O₃N could be synthesized, i.e. ZrAl₃O₃N could only be synthesized in high purity N₂ atmosphere, and that ZrAl₃O₃N was only synthesized on condition that the raw material composition included both AlN powder and nano-ZrO₂ powder. However, with increasing of AlN content, the XRD peaks of ZrAl₃O₃N and ZrN phase gradually reduced, and pure ZrAl₃O₃N was hardly obtained by in-situ reaction between AlN and ZrO₂ because of generation of ZrN as well.

Abstract: The development status of self-lubricating tool materials was reviewed in the present study, as well as the five basic types of self-lubricating tool and the current situation of nanometer materials in ceramic cutting tool. Based on these, the design idea of the functional gradient materials and nano-micro composite materials was introduced into the self-lubricating ceramic cutting tool materials, in order to develop new self-lubricating ceramic cutting tool materials with both good mechanical and frictional properties.

Abstract: The industrial solid wastes mainly include mining tailings and industrial slags. Their typical applications in glass-ceramics are reviewed. The compositional design of the glass-ceramics based on the compositional features of wastes and the routes to increase the percentage of wastes in the glass batches are emphasized. To increase the addition of industrial solid wastes in the glass preparation is one of the key factors influencing the utilization of the wastes. One way to achieve this is to apply different wastes with compositional complementarity in glass batches. A few successful examples are summarized in this paper to provide good references for the further related research.

Abstract: 0.997(KNN-LS-BF)-0.003V₂O₅ piezoelectric ceramics were prepared by the traditional sintering method. The effects of sintering time on structure and properties of 0.997(KNN-LS-BF)-0.003V₂O₅ ceramics were studied. With the increase of sintering time from 2h to 6h, the crystal phase changes from orthorhombic symmetry phase to tetragonal phase, and the properties in the piezoelectric constant d₃₃, planar coupling coefficient k_p, dielectric constant ε_r and dielectric loss tanδ all have been remarkably improved when the sintering time increase to 4h, then the properties of the samples would be deteriorated when the sintering time is over 4h. However, the mechanical quality factor Q_m would be deteriorated all along with the increase of sintering time.

Abstract: Biomorphic TiO2 was prepared by high temperature pyrolysis and a modified sol-gel route. The morphology and microstructure of TiO2 samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the biomorphic TiO2 mainly consists of rutile TiO2, and replicates the shape and part microstructure of the carbon template.