Advanced Materials Research Vol. 510

Abstract: Slide gates are installed at the bottom of a ladle or tundish to control the flow of molten steel. It plays an important role in ladle refining process and continuous casting. Al₂O₃-ZrO₂-C refractories are widely used as slide gate materials due to its excellent corrosion and thermal shock resistance. At the start of casting, molten steel almost 1600°C passes through the bore of slide gate, the plate is rapidly heated up, the temperature difference between the bore and edge part, the slide gates are subject to large thermal gradients, so there is large thermal stress in the plate. This paper will show the results of our improved slide gates with good thermal shock resistance.

Abstract: Sinter as an intermediate product of the iron making, is a multiphase medium, and the microstructure of finished sinter directly affects the quality of sinter. But because the sinter micro structure of the extreme irregularities, it is difficult to use the traditional quantitative methods on the accurate description, the introduction of the fractal theory provides us with new ideas. According to the characteristics of sinter SEM photos, and used the VC++ computer programming language, it is researched and designed that the fractal dimension of calculation program (FWJS) based on the sinter SEM microscopic photos, through which got the fractal dimension value and describe the microscopic structure of the sample quantificationally, which has very important practical significance for the fractal research of sinter .

Abstract: In order to further enhancing the ratio of load of the current intelligent industrial robot to its weight, and making the structure and movement of the intelligent robot develop rapidly toward the modularization, flexibility and reconfigurable mode, a kind of new-type intelligent robot hand material with high strength, light mass and large damping is proposed in the paper. The new composition material and its performance are also introduced and discussed in detail. Based on it, the specific preparation method and technology of the new-type composite material are given. The experimental results show that the weight of the intelligent robot hand material proposed in the paper can reduce by about 30% under the premise of ensuring the good strength of the intelligent robot hand.

Abstract: A mathematical model of alumina content determination in limestone by chrome azurol S photometry was established to compare the uncertainty factors during measurement process, the uncertainty sources which would influence the analysis result were discussed and evaluated in details according to JJF 1059-2010. The expanded uncertainty was obtained, and the result showed the uncertainties originating from the measurement repeatability and calibration curve were much larger than that of the others, which provide the basis for selecting a better determination scheme.

Abstract: Thorium resources and foundation of using Thorium resources in china are introduced in this work, the influenced of using Thorium resources on nuclear power development is analyzed, and accordingly the programme of using Thorium resources and overall design programme of the advanced nuclear system TACR are bring forward.

Abstract: Taking ca-bentonite as the raw material, the activation effect of active floridin prepared by mixed acids of H₂SO₄, HCl and C₂H₂O₄ is studied. The research results indicate that the main factors influencing the activity and decolorization ratio of floridin include volume ratio of mixed acids, liquid-to-solid ratio, reaction temperature and reaction time. When the volume ratio of mixed acids H₂SO₄: HCl: C₂H₂O₄=5:5:1, liquid-to-solid ratio =4:1, reaction temperature 80 and reaction time 4h, it is possible to prepare high-efficient active floridin.

Abstract: The anti-cracking performance of A1₂O₃-SiC-C based castables for trough was improved by the addition of foaming AC, using silica ash or silica sol as binder. The differential thermal analysis and thermogravimetric investigations were carried out on different matrix slip to investigate cracking performance. The results revealed that the three ways were all effective in improving the anti-cracking performance of the A1₂O₃-SiC-C based castables. Nevertheless, they differed in mechanisms: foaming AC could form a gas passage; silica ash or silica sol could avoid the reaction of silica with cement to generate a calcium aluminum silicate hydrate similar to zeolitic compounds. This will prohibit the release of a large amount of water vapor in a short time. Therefore, the anti-cracking performance was improved.

Abstract: In this work, a back propagation artificial neural network (BP-ANN) model is conducted to predict the flow behaviors of high-Nb TiAl (TNB) alloys during high temperature deformation. The inputs of the neural network are deformation temperature, log strain rate and strain whereas flow stress is the output. There is a single hidden layer with 7 neutrons in the network, and the weights and bias of the network were optimized by Genetic Algorithm (GA). The comparison result suggests a very good correlation between experimental and predicted data. Besides, the non-experimental flow stress predicted by the network is shown to be in good agreement with the results calculated by three dimensional interpolation, which confirmed a good generalization capability of the proposed network.

Abstract: A constitutive model using dislocation density rate as an internal state variable has been proposed for hot working of β titanium alloy in this paper. The β phase was only taken into consideration during high temperature deformation. The solution strengthening and dislocation interaction were included in the constitutive equations. The strength coefficient was determined by equivalent vanadium content, V_eq, which was calculated according to the alloy constituent. A Kocks-Mecking model was adopted to describe the variation of dislocation density. The constitutive relationship of a β titanium alloy Ti-10V-4.5Fe-1.5Al for high temperature deformation was established using the internal-state-variable based model. Model parameters were determined by the genetic algorithm based objective optimization method. The predicted results agree fairly well with the experimental value.

Abstract: TiC reinforced Ni-based composite coating added with 10% TiC particles was prepared on the surface of Q235 steel by plasma cladding. SEM as well as EDS and XRD were used to investigate the microstructure and formation mechanism of composite coating. The results show that between composite coating and substrate is metallurgical combination, and the microstructure of composite coating is composed of basic microstructure dendrite γ-Ni, interdendritic eutectic structure (α-Fe+Cr₇C₃+Fe₃C) and dispersed TiC particle. The maximum value of micro-hardness of composite coating added with 10% TiC particle is 440 HV_0.2.