Advanced Materials Research Vols. 217-218

Abstract: Snare space grapple device is designed for grappling large in-orbit payloads. Based on describing the grappling process, dynamic modeling of capturing a free-floating vehicle with large solar sails is performed by using Newton-Euler and hybrid coordinate methods in this paper. The models considering target vehicle as a rigid central body with flexible appendages which are discrete by using finite element method.

Abstract: The microstructures of three kinds of synthetical solid FeS, acting as a solid lubricant, which includes FeS bulk, FeS particle and FeS powder, were studied by transmission electron microscope (TEM) in this article. The TEM photographs showed that different shapes of FeS had quite dissimilar characteristics. The texture of FeS powder was the loosest among the three shapes, and it tended to forming flocculent aggregation; while FeS bulk and FeS particle were more dispersive. The electron diffraction results showed that the crystals of solid FeS were composed of many single crystals and multi-crystals, with two kinds of crystalline structure- hexagonal structure and face-centered cubic structure.

Abstract: In this paper, the structure and tribological properties of synthetic MoS2 film prepared by a novel compound technology—combining magnetron sputtering with low temperature ion sulfurizing were investigated. X-ray diffraction (XRD) pattern for the MoS2 film implies that the film mainly consists of Mo and MoS2 phases. The hardness of the synthetic MoS2 film was 7.44 GPa which was higher than that of the FeS film. The sliding tribological behavior of the MoS2 film was studied by ball-on-disc tests. The results showed that the synthetic MoS2 film possessed excellent friction-reducing and wear-resisting properties. In addition, the tribological behaviors of the MoS2 film were superior to those of the FeS film and original 1045 steel.

Abstract: It has gained some popularity that optimization methods are used for identification of material parameters, furthermore because of non-linear relationship between identified parameters and foregone information, mostly parameter identification problem must be expressed in terms of a global optimization problem. In order to solve successfully non-linear parameter identification problem, a new global optimization algorithm, which is based on the general dynamic canonical descent method, is proposed. The results in numerical experiments and engineering application both show that the proposed method will be robust one in the field of non-linear parameter identification.

Abstract: In this article, solid lubrication FeS film was prepared on the surface of AISI 1045 steel by means of low temperature ion sulfurizing process. Scanning electron microscopy (SEM) was utilized to observe the surface and cross-section morphologies of the sulfurized layer. The element distribution of the sulfurized layer surface was analyzed by X-ray energy spectrometer. The crystalline phases were determined by X-ray diffraction (XRD). X-ray stress determinator was utilized to measure the residual stress in the sulfurized layer. The nano-hardness and elastic modulus of the sulfurized layer were surveyed by a nano-indentation tester. The results showed that the surface of the FeS film was composed of many minute spherical particles with homogeneous grain size and distribution. The texture of the film was very loose with lots of micro-pores, and the crystallinity was well. There was compressive stress in the FeS film, and the stress value measured is -150 MPa. The average value of nano-hardness and elastic modulus were 4.02 GPa and 157.36 GPa respectively.

Abstract: In this paper, we adopted a novel method, namely, magnetron sputtering + low temperature ion sulfurizing composite technology to prepare synthetic MoS2/FeS multilayer film. The obtained film has a quite smooth surface with plenty of spherical particles. The friction tests were carried out on a ball-on-disc tester under dry condition. During the whole test, the friction coefficient of the MoS2/FeS multilayer film was always lower than that of the original 1045 steel and FeS film. In addition, the wear scar depth of the MoS2/FeS multilayer film was also low. It is undoubtedly that the synthetic MoS2/FeS multilayer film possesses excellent friction-reducing and wear-resisting behaviors.

Abstract: The microstructural evolution and mechanical properties of as cast AZ91 Mg alloy enduring different homogenization conditions were researched. The results show that the peak stress and plasticity obtain improvement with the increase of heat treated time and temperature until 693K. When the temperature is higher than 743K, the sample will occur the over-burned and directly lead to the decrease of mechanical properties. Otherwise, with the increase of heat treated time and temperatures, the second phase gradually precipitate from the solution, while the grain evolution is not obvious. In the compression process for the samples after heat treatment, some twins could be found in the grains.

Abstract: Based on energy saving, environmental protection and use of agricultural residues, rice straw/starch composites were manufactured using molding method. The influence of manufacturing parameters (time, pressure and temperature) on flexural strength, flexural elastic modulus and tensile strength of the composites had been studied. The microstructure of fractured surfaces was further observed. Results showed that when the manufacturing parameters are: time of 47min, pressure of 19MPa and temperature of 156°C, the composites have higher mechanical properties. The mechanical properties increase with increasing of pressure. The interface, soakage and compatibility of cassava starch and straw are better, starch content is 16%, and straw/cassava starch composites have higher mechanical properties.

Abstract: To improve damage tolerance performance, GLARE was used as bonded crack retarders in this paper. Fatigue tests were run with unbonded and bonded samples; then test results between them was compared. Thermal residual stresses had been studied. It was found that bonded crack retarders can improve damage tolerance performance and capability. Thermal residual stresses have a detrimental effect on the fatigue crack growth rates by means of increasing the effective R-ratio applied on the aluminium substrate. Finite element analysis was carried out and the result was in good agreement with the experimental data.

Abstract: At present as the improvement of the standard of peoples’ living, the consumption of the catering industry has increased continually. However, the daily operation of the traditional catering enterprises relies on the manual management. It is not only a waste of manpower, but also causes mistakes such as missing or repeating, which depress the efficiency of the management. It is exigent necessary to use the efficient computer management to improve efficiency. In this research, a systematic solution is provided. It introduces the designing and implementation for some key modules of the multimedia order system. Multimedia order system can be a very important part of restaurant management system. The application of this system will not merely bring the good economic benefits to food and beverage enterprise, and is favorable to the advanced science and technology popularization and application in national economy, bring good social benefit.