Advanced Materials Research Vols. 1030-1032

Abstract: A research field on semi-solid metal processing is the preparation of semi-solid slurry with non-dendritic microstructure. Nowadays, with the technological innovation of semi-solid slurry preparation, people turn to produce the non-dendritic semisolid microstructure by locally cooling of the alloy melt during solidification. Therefore, it is necessary to investigate the formation mechanism of the non-dendritic microstructure formation because the primary phase undergoes a specially controlled nucleation and growth which distinctly different from the commom solidification. In this paper, the semisolid slurry of AM60 alloy was produced by Self-Inoculation Method (SIM), and the microstructure evolution of primary α-Mg was investigated by water quenching method and metallographic analysis. The results indicate that the semisolid microstructure of AM60 alloy produced by SIM composed of small and globular α-Mg particles, and these grains undergone a coarsing process during quiescent holding. The solid substrate caused by the fusion of solid particles and the dendritic fragments caused by melt flow caused the grain multiplication, and then the grain undergone a steadily growth because of the uniform temperature distribution, resulting in the increase of grains density and a small grain size of the AM60 semisolid slurry.

Abstract: To study the influence of layer charge and modifier on wettability plays an important role on the diagnosis of oil reservoir. In this paper, two quaternary ammonium salts (QASs) with different chain-length were used singularly or in compound form to modify the reduced-charge montmorillonites (RCMs). The wettability alterations of the organo-RCMs for deionized water and cyclohexane were studied based on capillary rise method. The results showed that RCMs singularly modified by QASs show different wettability characteristics. Moreover, there is a synergistic effect on the wettability when the RCMs are compound modified by two QASs and the organo-RCMs turn to more hydrophilic. The results of this work also indicated that it is possible to regulate the wettability of the RCMs by choosing different recipe of QASs, which is helpful to provide theoretical guidance for the oil production.

Abstract: Effect of subcritical quenching temperature on microstructure and mechanical properties of 22SiMnCrNi2Mo steel was studied. Conventional quenching was performed for tested steel to compare with subcritical quenching. The results show that morphology and number of ferrite change with the increase of subcritical quenching temperature. The shape of ferrite evolved from block to thin strip, and the number decreased. Ferrite and martensite formed strips spaced parallelly at subcritical quenching temperature 800°C.Steel presented good strength and ductility, while hardness is lower than conventional quenching.

Abstract: This paper briefly summarizes the new materials and their current status; discusses the characters and key points of application; at the same time, this paper conducts a further analysis on the style, external outline, internal details, function of texture, practicability and color application; and summarizes the influencing factors during the process of sweat production and contexture based on the characters of raw materials to provide with certain theoretical reference for related designers

Abstract: Electroless plating technology was applied in order to improve the poor wettability between the copper and SiC. SiC_p/Cu composites were frbricated by hot-press sintering technique. The influences of SiC particles (Cu-coated and Cu-uncoated) and SiC_p/Cu-5vol%n-SiC on microstructures, relative density, bending strength and coefficient of thermal expansion(CTE) were researched in detail. The results show that SiC particles distributed in Cu matrix uniformly. And a certain amount of SiC, the relative density and bending strength of SiC_p/Cu(Cu-coated) composite were greater than SiC_p/Cu(Cu-uncoated) composite, and the coefficient of thermal expansion was opposite, Between SiC_p/Cu(Cu-coated) and SiC_p/Cu-5vol% nanoscale SiC(n-SiC), the relative density and bending strength of SiC_p/Cu(Cu-coated) were more than SiC_p/Cu-5vol%n-SiC, and CTE was different.

Abstract: The grain refining technology of AZ31 alloy by using self-inoculation method (SIM) has been developed. Results indicated that SIM significantly decreased the grain size of as-cast AZ31 billet from 287 to 58 μm, changed the morphologies and size of the β-Mg17Al12 phase and decreased the solute elements segregation along grain boundaries. The average grain size is sensitive to the diameter of a cast rod; the microstructures of the large diameter rod are relatively inhomogeneous. The grain refinement was mainly attributed to the grain multiplication which derives from heterogeneous nucleation induced by self-inoculants and free crystals and dendrite fragments enhanced by fluid director, combined with a high solidification rate of alloy melt in the metal mold.

Abstract: Magnetic molecularly imprinted polymers (MMIPs) based on poly [2,2’-(p-oxidiphenylene)-5,5’-bibenzimidazole] (OPBI) composites were synthesized for the selective adsorption and detection of nonylphenol (NP) from water samples. During polymerization, Fe₃O₄@C was used as supporter and magnetic substance and OPBI not only was used as crosslinking agent but also functional monomer. Morphology of Fe₃O₄@C and MMIPs were investigated by scanning electron microscopy (SEM). The kinetics of adsorption followed the pseudo-first-order model. Selectivity of MMIPs was further demonstrated through HPLC analysis of the water samples, in which bisphenol A (BPA), phenol, 4-nitrophenol (4-NP) and tetrabromobisphenol (TBBPA) were dissolved respectively. The result showed that MMIPs had more effectively recognition capability of NP than other contrasts.

Abstract: The coal gangue are produced in a coal mine heap of Pan xian, Gui zhou, by using microwave assisted acid leaching methods and under certain reaction conditions, the products of different stages of acid leaching were characterized through different characterization methods like X-ray diffraction, scanning electron microscope and energy dispersive spectroscopy. The related process mechanism of Microwave assisted technique acid leaching gangue was preliminarily studied by the characterization results from analyzing the products of different stages of acid leaching.

Abstract: Molecular conformation and binding modeling were built by Hyperchem 8.0 computational chemistry package and the optimum molecular conformation was obtained by molecular mechanics optimizer. It was found that there were two types of binding sites for norfloxacin on the molecular imprinted particles (MIPs).One was the hydrogen bonds between oxygen atom of MIPs with the carbonyl group of norfloxacin and the other one was the hydrogen bonds between oxygen atom of MIPs with the hydroxyl group of norfloxacin. Moreover, the energies change of the molecules were1.69 x10⁶ J/mol, 1.80x10⁶ J/mol and 5.37x10⁶ J/mol and 2.54 x10⁶ J/mol during the binding process of the norfloxacin (NOR), ciprofloxacin (CIP), bisphenol A (BPA) and tonalide (TON) onto the MIPs, respectively. The result indicated that the MIPs had a good selectivity for NOR and CIP than BPA and TON.

Abstract: Steel slag has potential hydraulic reactivity, it can replace raw material for making cement clinker, or directly product slag cement as admixture, but there is a problem that it has a lower activity as the admixture to produce slag cement. The reasons for lower activity of steel slag and motivation of steel slag activity were discussed in detail.