Advanced Materials Research Vols. 150-151

Abstract: CuFe10 and CuFe15 (mass fraction) alloys were prepared by vacuum induction melting and were cold rolled heavily at room temperature. Microstructure, microhardness and electrical conductivity of these alloys were measured at various cold rolled strain levels. The experimental results showed that the microhardness increased rapidly and the electrical conductivity decreases gradually with the increase of rolling strain at first. The microhardness increased slowly while the strain η greater than 2.3. The Fe-rich phases are deformed to ribbons filaments. However, the electrical conductivity increases again after deforming to a certain degree. The final electrical conductivities of heavily cold rolled CuFe10 and CuFe15 alloys were slight lower than vacuum inducing melted master alloys, however, the microhardness had increased about 44% and 47%, respectively.

Abstract: Copper-carried zirconium phosphates (CuZrPs) were prepared by introducing copper ions into sodium zirconium phosphate (ZrP) through an ion-exchange method, and characterized by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The antibacterial activity and water resistance of CuZrPs were also investigated. The research results indicated that CuZrP-3 containing 10.86 mass% of copper exhibited excellent antibacterial activity and water resistance.

Abstract: Recycled PET is an important resource of waste, which reused with polar or crystallization polymers, such as PC, PA and PE, by melting blend method have been well studied. But the study of rPET blend with nonpolar and amorphous polymer is still inadequate. In the present work, nano-SiO2 particles were introduced to recycled PET/ABS/AES (55/40/5) blends by extrusion processing. It has been investigated how nano-SiO2 particles influences the morphology and mechanical properties of rPET/ABS blends by the use of AES as compatibilizer. It showed a uniform dispersion of the nano-SiO2 components, and the two-continuous phase of rPET/ABS was more evenly when the content of nano-SiO2 particles at a low level. The tensile strength and beam impact strength of rPET/ABS/AES blends were increased at the same time by adding nano-SiO2 particles..

Abstract: According to a series of experimental studies such as the content of the f-CaO, the relative grindability index of the gas quenching steel slag, the properties of gas quenching steel slag cement and a detailed analysis of the potential economic benefits of steel slag cement. It was found that it has a huge economic benefits in preparing the cement with gas quenching steel slag.The results showed that the content of f-CaO in slag particles less than 2mm were no more than 2.7% and there exists a well proportional relation between it and the grain size; the grindability of gas quenching steel slag is much better than heat-stew steel slag; what's more,because of the high hydration activity of gas quenching steel slag, it can be produced the perfect steel slag cement with excellent hydration, stability and strength.

Abstract: Al-4.5 wt. % Cu matrix composites reinforced with in situ SiC particles were synthesized using direct reaction synthesis (DRS). The microstructure and tensile properties of the in situ composites were examined by optical microscopy (OM) and transmission electron microscopy (TEM). The results showed that the in situ SiC particles could be obtained through the appropriate control of the fabrication parameters. The heat released by the formation of TiC effectively promoted the formation of SiC. The size of the in situ SiC particles in the matrix was about 0.2 μm.

Abstract: The steady thermal stress distributions and effect factors in a ZrO2/FGM/Ti-6Al-4V composite ECBC plate with temperature-dependent material properties under convective heat transfer boundary were investigated by the NFEM and the Sinpson method. From numerical calculation, when , T0=300K, Ta=350K and Tb=1 750K, the thermal stress distributions in the composite FGM plate were obtained. The results are as follows. With the increase of the FGM gradient layer thickness and when M=1, the temperature distributions in the composite plate are more reasonable. With the increase of the FGM gradient layer M, the thermal stresses on the ceramic surface tend toward reduction, and compared with the thermal stress of M=0.2, the thermal stress of M =5 reduces by 17.8%. When we take into account the effect of temperature-dependent material properties, compared with the results of constant material properties, the maximum compressive stress on the surface of metal reduces by 74.2%, and the maximum compressive stress on the surface of ceramics reduces by 45.3%. With the increase of FGM layer porosity P, the change of stress at the bonding interface of the three-layered plate increases, and the stress curves appear peak values. Compared with A=0, when A=3.99, the compressive thermal stress on the metal surface reduces by 42.0%, and the compressive thermal stress on the ceramic surface increases by 154.7%. Compared with the nongraded two-layered ceramic/metal composite plate, the thermal stress of the ZrO2/FGM/ Ti-6Al-4V composite plate is very gentle. Compared with , when , the maximum compressive stress on the surface of metal reduces by 49.98%, and the maximum compressive stress on the surface of ceramics increases by 182.3%. The results provide the foundations of theoretical calculation for the design and application of the composite plate.

Abstract: Boron-containing bisphenol-A formaldehyde resin (BBAFR) with different amounts of boron was synthesized from bisphenol-A, formaldehyde solution and boric acid. The fiber-glass reinforced laminates were prepared. The thermal, electric and mechanical properties were determined. The results show that the BBAFR has a better thermal stablitity. The residual rate of BBAFR is 18% at 900 oC, which is higher 300 oC than ordinary phenolic resin. The tensile strength of BBAFR fiber-glass laminates is higher 19.07MPa than ordinary phenolic resin fiber-glass laminates. The volume resistivity and surface resistance of BBAFR laminates increased, but the dielectric loss tanδ and dielectric constant ε decreased.

Abstract: The Fe-based amorphous coatings were prepared by Air plasma thermal spraying. X-ray diffraction results show that the coating fabricated at current of 300A has an amorphous structure. The amorphous nanocrystalline composite coatings were obtained at current more than 300A. The friction and wear properties of the coatings were investigated in Ml-10 friction and wear tester at dry friction condition. The results show that the amorphous content is the main influencing factors to wear resistance of coating. The density of coating is another reason to affect the wear resistance of amorphous nanocrystalline composite coating.

Abstract: The disposal of circulating fluidized bed (CFB) fly ash has been a serious environmental problem in the development of our society. In this work, the feasibility of recycling CFB fly ash as a blended material incorporating blast furnace slag (BFS), clinker and gypsum for the preparation of Eco-cement has been investigated. The mechanical properties of CFB fly ash based Eco-cements, including CFB fly ash–clinker system, CFB fly ash–ground BFS system, and CFB fly ash–ground BFS–clinker system, were evaluated in this paper. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used to analyze the microstructural changes and the hydration products of the CFB fly ash based Eco-cement pastes. The results indicated that it is feasible to use CFB fly ash along with BFS and clinker to produce Eco-cement. The hydration products of CFB fly ash based Eco-cement are mostly ettringite and amorphous C-S-H gel, which are principally responsible for the strength and structure development of CFB fly ash based Eco-cement in the hydration process.

Abstract: In solvent extraction system of perrhenate with the extractant of N235 at high concentration, the equilibrium molalities of ReO4- were measured at ionic strengths from 0.2 to 2.0 mol.kg-1 in the aqueous phase containing Na2SO4 as the supporting electrolyte from 278.15K to 303.15K. The standard extraction constants K0 at various temperatures were obtained. Thermodynamic quantities for the extraction process were also calculated.