Advanced Materials Research Vols. 335-336

Abstract: Fused quartz granules (d₅₀=19 μm) were used as raw material, and Si₃N₄-Nd₂O3 (1:1, in mass) was used as additive with dosages of 1% (in mass, similarly hereinafter), 2% and 3%. Fused quartz ceramic materials were fabricated in reduction atmosphere at 1300 °C, 1350 °C and 1400 °C for 1 h. The apparent porosity, bending strength and thermal expansion ratios of the samples were studied and the samples were further analysed by means of XRD and SEM. The results showed that the sample sintered at each temperature with 3% Si₃N₄-Nd₂O₃ had the lowest apparent porosity, the highest bending strength and more compact microstructure. This indicated that 3% Si₃N₄-Nd₂O₃ was useful to the sintering of fused quartz ceramic materials. The results of XRD and thermal expansion ratio analysis showed that 3% Si₃N₄-Nd₂O₃ compound additive had better effect on inhibiting crystallization of the samples sintered at 1300 °C, 1350 °C and 1400 °C.

Abstract: In order to enhance the thermal efficiency of heating and dring facilities, the energy-saving high infrared radiation materials were synthesized by the solid state method for 2h at 950, 1050 and 1150 °C, respectively, and rapid cooling in the air, from transitional metal oxides Fe₂O₃, Cr₂O₃, MnO₂ andCuO. The strcture and emission property of the samples were characterized through X-ray diffractomete, scanning electron microscop and infrared radiation meter. The results show that the main phases of resultants are spinel ferrites, and with increasing temperature, crystals become better and multiple spinel and like-spinel structures are formed. The infrared radiance represents a nonlinear variation with calcining temperature. The coatings on the stainless steel surface prepared with the materials with self-made binders have good infrared radiation, up to a maximum of 0.90, and have perfect resistance to thermal shock and may arrive at 25 times (RT←→800 °C), exhibiting fairly high binding strength. So the materials which are apply to on the internal wall of heating and drying facilities are believed to result in an long-term energy conservation.

Abstract: The Al₂O_3(nm)/SiC_（μm）/Al₂O_3（μm）ceramic tool materials were fabricated by the hot-pressing technique. Effect of the compositions on microstructure and mechanical properties is investigated. With nano-particles content decreasing, the flexural strength increased and fine grains can be obtained. When the nano-alumina content is 60wt%, the grain of this sample is fine, the Vickers hardness and flexural strength are 16.24 GPa and 678 MPa, respectively.

Abstract: In the construction of high-rise buildings, large span structures and tall structures, the combinatorial design structure of high strength concrete, steel fiber concrete, prestressed tendon and ordinary steel bar is a main measure to bring the advantages of high strength concrete into full play. This paper studies the nonlinear constitutive relations of high strength concrete, steel fiber concrete and steel bar. By using finite element method, this paper carries out a numerical simulation of the whole monotonic loading process of box prestressed continuous beam of high strength concrete - steel fiber concrete and gets comparatively detailedc calculating results, which provide a theoretical reference for the reasonable combinatorial design of high strength concrete,steel fiber concrete, prestressed tendon and ordinary steel bar.

Abstract: Polarization curves, corrosion potential, scanning electron microscopy (SEM) were adopted to investigate the corrosion behaviors of QSn4-3 under two kinds of marine advantage bacteria (anaerobic SRB and facultative anaerobic Vibrio natriegens) environment. The results show that the microbial film has some effects on inhibiting corrosion of QSn4-3 at the early stage of corrosion; the existence of marine microorganisms accelerates the corrosion process of QSn4-3; the combined action of SRB and V.natriegens accelerates the corrosion obviously and QSn4-3 coupon is more prone to pitting corrosion.

Abstract: This paper utilizes a product certified by Green Building Material Label (TGBML) in Taiwan on comparing the benchmarks of emission, test methods and compounds with other green building material labels, especially focusing the analyte on HCHO and VOCs. On a statistical basis, we get the test values of 288 low-emission products certified by TGBML. The average emission rates of HCHO and VOCs are as follows: HCHO=0.0028 mg/m²*hr, and TVOC=0.0683 mg/m²*hr. (Benchmarks of low-emission product of TGBML are as follows: HCHO=0.08 mg/m2*hr, and TVOC=0.19 mg/m²*hr) This paper reveals that the product certified by Taiwan Green Building Material Label (TGBML) can pass the benchmarks of other 3 building material labels. In order to promote a healthy IEQ environment in Taiwan, these results may provide stricter low-emission benchmarks and suggestions of other compounds which can be added to the prerequisites of tests in Taiwan.

Abstract: The objective of this work was to study the production of new biodegradable thin films. As a result of increasing problems with regard to the disposal of domestic waste, particularly plastics, a new class of polymers especially designed to be biodegradable has been undergoing development. However these biodegradable plastics still have a limitation, i.e. high cost. This research studied methods of lowering the cost of biodegradable plastic and of improving its properties by using epoxidized natural rubber as a another polymer for polymer blends. Thus, ternary blends of epoxidized natural rubber (ENR), poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) were studied and prepared using a twin-screw extruder, followed by use of a chill roll cast film extruder or a blown film extruder, to produce biodegradable film. The concentration of ENR in the ternary blends was fixed at 10 wt%, with the remainder being PLA and PBAT. In some proportions of the film blends, Irganox and Uvinul were introduced to increase the thermal stabilization and UV stabilization, respectively. The mechanical and thermal properties were evaluated, including the thickness, color, and water vapor permeability (WVP) of the biodegradable films.

Abstract: Studying the microstructures of ZL116 alloy slurry prepared by nearby liquidus electromagnetic casting (NLEMC), electromagnetic casting (EMC), and nearby liquidus casting (NLC) by means of electron microscope and image analysis apparatus. At the same time, determining the their hardness by using hardness instrument. The results show that the NLEMC can obtain the fine and uniform equiaxed grains structure, its average-area-circle grain diameter is 28.5μm, and its rheoforming parts, hardness is 129Hv. All of these also show that the slurry microstructure and rheoforming properties of ZL116 prepared by NLEMC are the best in the three kinds of ways. At the same time, discussing the mechanism of NLEMC structure fine.

Abstract: The article presents the results of optical microscopy, scanning electron microscopy (SEM), Transmission Electron Microscope (TEM) conducted on a Ti–46.5Al–2.5V-1.0Cr–0.3Ni alloy before and after different heat treatments. Heat treatment of the alloy at 1340°C followed by cooling leads to the formation of the fully lamellar microstructure which consists of γ lamellae mostly and of small amount of α2 lamellae. The cooling rate of 50°C/min in alloy tcx1-G produced an optimal microstructure. This cooling rate generated finest lamellae with the smallest individual lamella spacing among the alloys.

Abstract: Corrosion behaviour of hot-dip galvanized steel in 5% NaCl aqueous solution was studied by electrochemical impedance spectrum (EIS) technique. The results revealed that corrosion behaviour of hot-dip galvanized steel has a great relationship with immersion time. With the increase of immersion time, corrosion products are constantly changing, and the impedance of corrosion products are different. Parameters fitted by equivalent circuit show that the impedance of corrosion products increased at first, then decreased.