Advanced Materials Research Vol. 968

Abstract: The constitutive equations may properly describe the flow behavior of the materials. In the present study, the constitutive equation of Mg-13Al-3Ca-3Zn-1Nd-0.2Mn alloy were investigated using hot compression tests at the temperatures range of 200, 250, 300, 350 and 400°Cwith the constant strain rates of 0.001, 0.01, 0.1, 1 and 10s^-1.The hot working constitutive base analysis has been conducted on the experimental alloy. The related material constants n, α and β, as well as the activation energy Q for each temperature regime have been determined. At last, the constitutive equations is given.

Abstract: The high strain rate deformation behavior of as-annealed and as-cold rolled pure titanium was inspected by Split Hopkinson Pressure Bar (SHPB). The effect of deformation structure on adiabatic shear behavior in pure titanium was analyzed from the aspect of dynamic mechanical response and microstructural evolution. It was found that the strong {0001} basal texture was formed in as-cold rolled pure titanium. There were Geometrically Necessary Boundaries (GNBs) with spacing of 0.6μm and Incidental Dislocation Boundaries (IDBs) with size of 80nm in one grain. The enhancement of adiabatic shear sensitivity in as-cold rolled titanium was attributed to the deformation induced dislocation boundaries. The core of adiabatic shear band (ASB) was full of fine equiaxed grains with average size of 0.4μm, which was induced by dynamic recrystallization.

Abstract: The study aimed at development of mechanical properties to make a comparison between Sn-50wt%Zn and Sn-50wt%Bi were investigated by properly design experiments, respectively, different mold temperature affecting the particle size of Sn-50wt%Zn, mechanical properties and microstructure were developed by GISS process, hardness test were used to compare both alloys. The results show that mold temperature has an effect on the grain sizes and grain characteristics. Gas Induce Semi-Solid (GISS) caused granular grains to affect the good mechanical properties.

Abstract: Pyrocarbons were obtained by heat-treatment of Ketjenblack at different temperature from 1000°C to 2400°C, and fluorinated in NF₃ atmosphere at 520°C to give CF_x samples with high fluorine content. The results indicate that the structure of both pyrocarbons and their derivative fluorides mainly depend on the heat-treatment temperature of raw carbon. The correlation between the electrochemical performance and the structure of pyrocarbon fluoride was discussed in detail. At an optimum condition, the yield of fluorination can come up to 90%, and the pyrocarbon fluoride, as cathode active material of lithium primary cell, gives an energy density up to 2200 Wh kg^-1.

Abstract: The nanocomposites between silicon-containing polyimide (SPI) and electrically conductive carbon black (CB) of low structure (Conductex K Ultra) were prepared. The contents of the conductive nanofillers were varied from 0 to 40 phr. The thermal properties of the nanocomposites were determined via Differential Scanning Calorimeter (DSC) and Thermo-gravimetric Analyzer (TGA). DSC thermograms revealed that the glass transition temperature (T_g) and degradation temperature (T_d) of the nanocomposites increased with increasing the amount of fillers. The T_g and T_d values of the composites filled with high structure were higher than those of the ones filled with low structure.

Abstract: The PVDF/PVC blending membrane has a certain application in the field of sewage treatment. In this paper, the simulation study for the blending ratio of the PVDF/PVC membrane has been carried on, which has an influence on the membrane’s ability of sewage treatment. Firstly, the membrane models were constructed via Amorphous Cell module of MS (material studios) 6.0. Secondly, the optimization processes were achieved via Minimizer and MD (Molecular Dynamics) method of the Discover module. Lastly, the diffusion coefficients D was calculated indirectly through the Mean square displacement (MSD) getting from Forcite module and the solubility coefficients S was calculated indirectly through the adsorption isotherm getting from Sorption module. It was found that the membrane had a best ability of sewage treatment when the content of PVC was 5% (mass fraction). And the calculated result was well consistent with experiment result.

Abstract: The effect of slag treatment with Copper addition in silicon purification by metallurgical methods was examined in this paper. The microstructures and contents of Si-Cu alloy after slag refining were investigated by XRD and ICP, respectively. The majority phases in the Si-Cu alloy were Cu₃Si and Si. The partition ratio of boron (L_B) between slag and silicon was studied with and without Cu addition. Experimental results show that slag treatment with Cu addition can improve the L_B in CaO-SiO₂-CaF₂ slag system, where a maximum boron removal ratio of 85% could be achieved.

Abstract: Rutile TiO₂ white pigment was prepared by self-seeded thermal hydrolysis route via short sulfate process from low concentration TiOSO₄ solution. Hydrolysis time had significantly influenced the structure and pigment properties of rutile TiO₂. The samples were characterized by XRD, particle size distribution and pigment properties test. The hydrolysis time had great influences on the hydrolysis rate, particle size distribution, crystal growth and particle aggregation of TiO₂, eventually determined the pigment structure and properties. The optimized hydrolysis time after second boiling point was of 2.5h. And the prepared rutile TiO₂ white pigment was with narrow particle size distribution and nice pigment properties.

Abstract: Short sulfate process was developed to produce rutile TiO₂ white pigment by using low concentration industrial TiOSO₄ solution as raw material via self-generated seeded thermal hydrolysis route. The concentration of TiOSO₄ solution had significantly influenced the structure and pigment properties of rutile TiO₂ white pigment. The samples were characterized by XRD, particle size distribution and pigment properties test. Appropriate concentration of TiOSO₄ was beneficial to promoting hydrolysis process in a proper way and obtaining favorable structure and high quality white pigment. The optimized concentration of TiOSO₄ solution was of 191.20 g/L.