Advanced Materials Research Vols. 602-604

Abstract: Inconel 713C alloy was tried to manufacture by using MIM(Metal Injection Molding) process. The high-temperature mechanical properties of MIMed Inconel 713C were also investigated. Processing defects such as pores and binders could be observed near the surface. Tensile tests were conducted from room temperature to 900°C. The result of tensile tests showed that this alloy had similar or somewhat higher strengths (YS: 734 MPa, UTS: 968 MPa, elongation: 7.16 % at room temperature) from RT to 700°C than those of conventional Inconel 713C alloys. Above 800°C, however, ultimate tensile strength decreased rapidly with increasing temperature (lower than casted Inconel 713C). Based on the observation of fractography, initial crack was found to have started near the surface defects and propagated rapidly. The superior mechanical properties of MIMed Inconel 713C could be obtained by optimizing the MIM process parameters.

Abstract: The phase-field model coupling with the concentration field and flow field is used to simulate the dendrite growth during isothermal solidification of Fe-C alloy in a forced flow. The effects of noise amplitude and interface thickness on the dendrite growth are studied. The results indicate that with noise amplitude increasing, the secondary dendrite arm average space(SDAAS) on the the upstream of the lateral principal branch decreases, but the dendrite tip velocity remained about the same. With an increase in the interface thickness, the principal and secondary branch of dendrite degenerated, the equilibrium morphology of the crystal changes from developed dendrite to compact dendrite, the dendrite tip solute concentration decreases first, then increases slowly.

Abstract: More than a hundred models of clusters Ni4-xFexP (x=0~4) have been designed and computed in duplicate and fourfold state on density function theory (DFT) to simulate amorphous alloys Ni80-xFexP20 that were the most familiar proportions in Ni-Fe-P amorphous system. The geometry, energy, electronic and catalytic properties have been discussed. The results disclosed that clusters could reflect some characteristic properties of binary amorphous alloys. And the clusters could predict the geometry and electron properties of corresponding ternary amorphous alloys. The addition of third element could enhance the system stability of Ni-P amorphous alloys. The metal atoms are the electrons gainers and metalloid atoms are the electrons offers in the clusters, and the ability of gaining electrons of atoms Ni is better than the one of atoms Fe. The trend of cluster Ni2Fe2P forming may be the keenest in clusters. It also would offer more excellent catalytic activity basing on Fermi level and density of state.

Abstract: A series of waterborne cationic perfluorinated polyacrylate (WCFPA) were prepared by the reaction of styrene (St), methacrylatoethyl trimethyl ammonium chloride (DMC), butyl acrylate (BA), octadecyl acrylate (ODA) and 2-(perfluorooctyl)ethyl acrylate (FEA) by soap-free emulsion copolymerization and then the films of the WCFPA were prepared. Their structure and water/oil repellency properties, such as surface property, water and chemical resistance of their membrane were characterized by fourier transform infared spectrometer (FT-IR), interfacial tension instrument (IT), contact angle (CA) and spot test. The results reveal that WCFPA was endowed with low surface energy of its film. It was also found that the fluorinated polyacrylate had outstanding water and chemical resistance. Increasing the FEA amount in the emulsion was as sociated with larger contact angle and better water and oil repellency.

Abstract: The impact of HPD722 macroporous resin on the dynamic adsorption and desorption of flavonoids in Thlaspi arvense Linn extract is studied. Obtained optimal conditions：the mass concentration of the sample solution is selected to be 4 mg•mL-1; while the flow rate of sampling is 1.30mL min-1; pH value is 4；50mL ethanol at a volume ratio of 70% is adopted as the desorption agent；the desorption flow rate reaches 3.47 mL•min-1. Under these conditions, the content of flavonoids increases from 5.09% to 21.91% upon purification by HPD722 macroporous resin.

Abstract: The effects of ethylene vinyl acetate grafting maleic anhydride (EVA-g-MAH )as a compatilizer on the mechanical properties, compatibility and morphological structure of thermoplastic Polyurethane and poly(vinyl chloride) blends were studied. The blends were prepared and characterized by mechanics properties test, scanning electron microscopy(SEM,)dynamic mechanical properties (DMA) and thermogravimetry(TG) . Mechanical properties indicate that the hardness, tensile strength, breaking elongation of the blends are greatly improved by EVA-g-MAH, when the critical EVA-g-MAH content at about 4 wt%.SEM micrographs reveal that EVA-g-MAH could bring down the diameter of dispersed , change brittle fracture into ductile fracture, and promote adhesion of phase interface. The glass transition temperature change by DMA proves that the addition of the EVA-g-MAH improved the compatibilization of blends. And the results of TG experiment show that EVA-g-MAH greatly improve the thermal stability of the blends.

Abstract: A kind of UV-curable cyclohexanone-formaldehyde resins (UVCF) was prepared by the reaction of cyclohexanone-formaldehyde resin (CFR), isophorone diisocyanate (IPDI) and 2-hydroxyethyl acrylate (HEA). The UVCF_IPID-HEA obtained was characterized by fourier transform infrared spectrum (FTIR), nuclear magnetic resonance (NMR). The FTIR and ¹H-NMR results show that the terminal acrylate acyloxy was introduced into the structure of the prepolymer. The results of solvent resistance tests show that the solvent resistance property of UVCF_IPID-HEA is excellent.

Abstract: The paper states the type and structure of large-scale LNG tank, discusses polyurethane foam performances and its application in a large-scale LNG insulation structure and makes a preliminary exploration to LNG tank low temperature insulation technology of our country. The paper has some reference values for large-scale LNG tank design and research.

Abstract: The formation of water tree in XLPE insulation material was inhibited by adding EAA(Ethylene Acrylic Acid),DBS(dibenzylidene sorbitol) into cross-linked polyethylene-based materials. The mixture was crosslinked through mixing and tabletting the blend at 160 degrees. The effect of additive content on the length of the water tree was investigated. The water tree cultivation experiment showed that the length of water tree decreased with increasing of the content of EAA and DBS in the modified compound.Its full property experiments results showed that the property of the insulation material fully meet the related requirements for the use of anti-watertreeing XLPE cable.

Abstract: The influences of ZnEt2 on ethylene chain transfer polymerization were investigated in detail and the polymerization mechanism was thoroughly analyzed. The results indicated that ZnEt2 contributed greatly to increase the activity of α-diimine nickel complex/ZnEt2/MAO(MAO: methylaluminoxane). It was striking that α-diimine nickel complex/ZnEt2 catalyst system (1/100 mol/mol) exhibited 8.0 ×104g/mol∙h activity, it was possible the formation of the ion pairs of Nickel and Zinc was convenient for ethylene chain propagation, however, the ion pairs were unstable in ethylene polymerization.