Advanced Materials Research Vols. 295-297

Abstract: The effect on heterogeneous nucleation of solute segregation was studied with segregating energy and segregating coefficient. The results showed that the segregating energyΔG^γ_segr of solute played a more vital role in the nucleating process, specially in the case that (1-k) is small. A critical criterion with the parameter was suggusted for estimating the nucleating abilitiy of the external particles in binary alloy, which had the vital theoretical or practical significance for choicing refiner.

Abstract: Based on approximation principle, water model experiment was carried out during teeming in a 60t steel ladle. Based on the previous research work, trapezoidal nozzlein with lager upper cross section was used to decrease the critical level of vortex in order to reduce the slag entrapment to the tundish. Different shape and height of upper part of the nozzle was investigated mainly to inhibit the vortex at the late stage of ladle teeming. When upper shape of trapezoidal nozzle is square, upper height is 20mm and 17mm, and eccentricity of nozzle is 3/4, critical height of vortex is about 34mm and 31mm. In this case, slag entrapment is controlled effectively and metal utilization is optimized more completely.

Abstract: The viscoplastic behavior of the fiber-reinforced metal matrix composites under the thermomechanical loading is discussed in this study. The theories of micro-mechanics with the concepts of average stress and strain are adopted and developed to integrate matrix, coating and fiber properties for predicting the stress-strain response. It is reduced to a set of the ordinary differential equations of one order that can be resolved by the numerical solution algorithms based on the classical fourth order Runge-Kutta method.

Abstract: Concrete member is usually stressed in structure. To test permeable behavior of concrete under load is significant in clarifying this characteristic. Currently, most of the methods measure the permeability of concrete specimen without stress. This paper describes a method that measures permeability of concrete subject to a uniaxial tension load. The main components of the test device include two parts. One is tension loading system, and the other is permeability system. The concrete member with 100×100×1000mm is designed to be the sample. A uniaxial tension load could be applied to the prism concrete specimen and the load was allowed to increase by steps until failure. Autoclam is adopted as permeability system. At each ground of the tension load the volumetric water flow through specimen is recorded with data acquisition automatically. The relationship between water permeability and increasing stress could be obtained with the suggested method.

Abstract: Using optical microscopy, electron backscatter diffraction and transmission electron microscopy, the static recrystallization (SRX) mechanisms of ZK 60 magnesium alloy was examined under twin-roll-cast and hot compression (TRC-HC, 350 °C/0.1 s-1) and subsequent annealing (1000 second at 250-400°C). The static recrystallization (SRX) mechanisms, such as grain boundary migration (GBM), grain boundary bulging (GLB) and subgrain rotation (SGR), were discussed.

Abstract: In this paper, the synthesis techniques of cationic cellulose by microwave irradiation method with bleached sulphate wood pulp and 3-chloro-2-hydroxypropyl tri-methyl ammonium chloride (CHPTMA) are investigated. The results show that the substitution degree of cationic cellulose and the Zeta-potential are the optimal under the conditions of the mass ratio of etherification agent to the cellulose 0.414, molar ratio of NaOH to ether agent 2.17, microwave time 9min, power 400W by the response surface experimental analysis.

Abstract: This paper presents an automatic test system which can output one 2Mbit / S PCM signals and one 10.2Mbit / S PCM signals for the device testing; the system wih self-test function could calibrate the output two PCM signals; when the equipment is in the state of testing, you can real-time monitor the status of the device through the PC

Abstract: By using vacuum melting, nitrogen protection and a high molten flow rate during pouring, many nano-TiN particles with the size of 20~100nm are formed during solidification of the alloy steel composed of C0.12- Si0.24 - Mo0.45 - Cr0.35 - V0.2 - Ti0.29 (wt.%). In addition, there are 0.9-1.4μm micron-sized particles separated by a space of 15~40μm. Precipitable TiN particles greatly refine the microstructure of the alloy steel. In this paper, the thermodynamic, kinetic mechanisms and related factors of TiN formation are analyzed.

Abstract: A novel kind of damping composite was prepared with polyester-type polyurethane/epoxy and functional inorganic particle, and the dynamic mechanical property, morphology and thermal stability were investigated. The results showed that the effective damping temperature region was broadened from 43.9°C to 132.6°C through the introduction of polyester-type PU into the epoxy matrix. With addition of functional inorganic particle, the maximum of damping peak increased from 0.75 to 1.44, and this was due to the special form of functional inorganic particle restricting the motion of the chains. The morphology study proved the existence of the micro-phase separation, and it was also observed that uniformly dispersed functional inorganic particle tightly implanted into the polymer matrix. Thermogravimetric analysis showed the composite filled with functional inorganic particle had better thermal stability.

Abstract: The presence of Fe and harmful effects on mechanical properties of pure aluminum and aluminum alloys are introduced. Several purification methods are reviewed, but all of them are of definite limitations. It is effective that precipitation method, filtration method and centrifugal division method are integrated.