Advanced Materials Research Vol. 904

Abstract: Based on the experimental and calculation results between the reinforcing particles content and thermal physical parameters, low pressure die casting of wheels was taken as an example to study the casting property of the 7075 alloy and TiB₂/7075 composites. The influences of die temperature, pouring pressure, pouring temperature and TiB₂ content on the filling of 7075 alloy and TiB₂/7075 composites wheels are studied by numerical simulation. Shrinkage porosity appears both in the spoke and rim of the wheel. The shrinkage porosity of the 7075 alloy decreases from 2.089% to 1.622% with mold temperature increasing from 100°C to 400°C. The shrinkage porosity of wheel decreases from 1.630% to 1.598% and 1.583% in the composite with 3 and 6wt.% TiB₂ particles. Besides, shrinkage porosities decrease with increasing pouring temperature.

Abstract: Pyrite composition characteristics can reflect its physical and geochemical formation backgrounds, also are the important parameters to further discuss the genesis of minerals and ore deposit. In this paper, major and trace elements of 13 pyrite samples from Dabaoshan polymetallic ore deposit were analyzed using EPMA, the results suggest that S/Fe atomic ratio of pyrite in dacitic porphyries were similar with reference standard value, however that ratio in granodioritic porphyries is 2.051, which is slightly higher than the reference standard value; trace elements Cu, Zn and Pb show the characteristic of high oxygen fugacity settings, the Co content in pyrite was significantly lower than that of Ni, and Co/Ni is far less than 1, all the evidences show the characteristics of sedimentation-reformation ore deposit.

Abstract: Nanocrystalline Fe-1.77at.%C and Fe-3.27at.%C alloys prepared by ball milling iron powders and graphite powders are annealed below 573K where the precipitation of Fe₃C does not occur. Upon annealing, a significant grain coarsening is observed in Fe-1.77at.%C alloy, whereas the grain coarsening is inhibited in Fe-3.27at.%C alloy. Within the framework of thermodynamic theories, the inhibition of grain coarsening in nanocrystalline Fe-C alloys is discussed. It is demonstrated that the inhibition of grain coarsening in the nanocrystalline Fe-C alloys can be ascribed to a vanished driving force for grain growth which is caused by the interaction between carbon and the grain boundaries of nanograins.

Abstract: The development of edible packaging material was introduced in this paper. The concept, types and the characteristics of edible packaging material were expounded separately. The history and main representational technologies in the development of edible packaging material in China were recommended. And the developing direction in the world was also explained in detail. The future development of this kind material was discussed. And the prospect of edible packaging materials was brought forward.

Abstract: The harmful ingredients in packaging materials and containers usually migrate to food during the machining and printing period. The permeability of packaging materials is very important for the food packaging safety. Several commonly used packaging materials were researched in this paper. Their permeability was characterized including the gas permeability, light-transmitting property, and the water vapor permeability. Some technologies which could improve the barrier property were brought forward. And the factors that impact the permeability were discussed in this research. Research on the permeability of packaging material is significant for food industry.

Abstract: N-Hexyl-4-(thiophen-2-yl)-1,8-naphthalimide (HTNI) is one of the 1,8-naphthalimide derivatives with excellent fluorescence property. A scheme of time-dependent density functional theory (TDDFT) and configuration interaction singles (CIS) approach in conjunction with polarizable continuum models (PCMs) are employed to make a detailed investigation of the emitting energy. The transition energies of absorption and emission are computed using five exchange-correlation (XC) functionals, B3LYP, PBE0, M06, CAM-B3LYP, and wB97XD as well as 6-31G* and 6-31+G* basis sets. The results show that the predicted emitting energies as well as the absorption ones are dominated mainly by XC functional to be used. By comparing the calculated electron transition energies to experimental observations, it is found that PBE0 functional in combination with 6-31G* basis set is the best method to reproduce the experimental spectra of HTNI.

Abstract: In this paper, we use residue of ten different Chinese herbal medicine as raw material and ZnCl2, KOH,K2CO3 as activator, using chemical activation method to prepare activated carbon, and we do performance testing on the activated carbon. The experimental process includes the preparation and properties testing of activated carbon, as well as testing the content of leading components of lignin in these Chinese herbal medicine raw materials and their calorific values. We've studied the relationship between leading components of these raw materials and out put and properties of the activated carbon. As a result, we got that using KOH and K2CO3 as activator to prepare activated carbon is a good choose for residue of Chinese herbal medicine belonging to rootstock which contains high content of lignin.And ZnCl2 for residue of Chinese herbal medicine belonging to cane.

Abstract: Zinc oxide (ZnO) thin films were deposited by radio frequency (RF) magnetron sputtering technique on glass substrates in pure argon gas. The optical transmission stectra of the films were measured by ultraviolet-visible spectrophotometer. The effects of argon gas pressure on optical properties of the deposited films were investigated. The optical band-gap of the films was evaluated in terms of the Taucs law. The results show that the argon gas pressure has slightly affected the optical band-gap of the deposited films. Furthermore, the refractive index and extinction coefficient of the films were determined by means of the optical characterization methods. Meanwhile, the dispersion behavior of the refractive index was studied by the single-oscillator model of Wemple and DiDomenico, and the physical parameters of the average oscillator strength, average oscillator wavelength, oscillator energy, the refractive index dispersion parameter and the dispersion energy were obtained.

Abstract: This paper studies the copper/aluminum/stainless steel (Cu/Al/STS) three-ply clad sheet rolling process. Cu/Al/STS clad sheet rolling process and mechanical properties were investigated , the results shows that with the increase of rolling reduction rate, the tensile strength of the clad sheet increasing and the cupping value decreasing, when the reduction rate is 33.3% ,clad elongation can be up to 72.2% and tensile strength up to 336MPa.The cupping test of the clad sheet is larger when the ply of STS is in the inner side of the cup than the ply of Cu in it. The best rolling process for Cu/Al/STS three-ply clad sheet is six-ply symmetric combination, heating temperature 350 ° C, heating time 5 ~ 10mins and rolling reduction rate is 33.3%.

Abstract: This research was to study the effect of hard milling on the surface finish of medium carbon steel. The sample specimen was selected to AISI 1050. The vertical milling process was chosen to experiment, which used insert PVD carbide tool. The experiment was applied on factors: cutting speed, depth of cut and feed rate and they were consisted of three levels. The factorial design on 3³ experiments was applied. The surface roughness average (Ra) was indicated for surface finish. The experiment results were analyzed by ANOVA. The main factors and factors interaction that affected to surface finish were investigated. Effect of cutting speed, feed rate and depth of cut on surface finish of harden medium carbon steel was discussed.