Advanced Materials Research Vols. 156-157

Abstract: The quasi-static contact finite element analysis of meshing gear of gear-box is computed by using MSC.Marc software, then transmission error and surface contact stress of meshing gear are computed in different tooth profile modification methods. Due to the large load fluctuation of tracklayer, the target of tooth profile modification is suggested, which is to minimize the peak value of tooth contact stress to the full, and not to increase the transmission error fluctuation of gear system.

Abstract: The high temperature deformation behaviors of Ti-47Al-2Cr-2Nb-0.2W alloy were investigated by isothermal compressive tests, performed at temperatures between 1000 and 1150 , strain rates between 0.001s-1 and 1s-1. The stress-strain curves of IM alloy exhibited an obvious work hardening peak followed by a broad flow softening at high strain rates(≥0.1s-1) while work hardening could hardly be seen from the stress-strain curves at low strain rates(≤0.01s-1). Also, the constitutive equation of the alloy had been established to describe the flow behavior. The apparent activation energy of hot deformation was calculated to be 351.61kJ/mol. The size of the recrystallized grain increased with increasing temperature and with decreasing strain rate, namely with decreasing the Zener-Hollomon parameter Z. It is necessary to select proper Z, that is, to strictly control the deformation parameters in order to obtain a homogeneous and fine microstructure.

Abstract: In this paper the multiprocessor task scheduling problem with variable job profile is addressed. Such problem originates from many practical resource assignment contexts. Based on discretized parameters, the problem is formulated as an integer programming model. Due to the complexity of the problem, a Lagrangian relaxation is applied to solve the problem. The numerical experiment demonstrates the effectiveness of our algorithm procedure.

Abstract: Robust tolerance design is an effective way to reduce the production risk. Traditionally, manufacturing cost and product quality are considered to be the optimization objectives. Designers often adopt the single-objective optimization or establish a comprehensive evaluating function combining several optimization objectives with different weights. It may not be desirable as it is difficult to identify the weights and balance the conflicting demands reasonably. This paper presents a kind of game approach to solve the robust tolerance design problem for automotive body products. Instead of designing specific objective functions, some measuring data in the manufacturing process are collected, and a robust game model considering the cost and the quality demand is established by transforming the part and the product information into relevant game components. The Nash bargaining method (NBM) of game theory is adopted to attain a balanced solution. It calls on two players in a game to start negotiation from a reference vector and achieve a trade-off vector as far as possible from the worse situation. Finally, an example of vehicle fender demonstrates the application and the performance of this method.

Abstract: The semiconducting behavior of passive film formed on 316L stainless steel in borate buffer solution containing sulfide was studied by capacitance measurements. The results indicate p-type semiconducting behavior related to chromium oxide of the passive film at -1.12 ~ -0.78V and n-type semiconducting behavior to iron oxide at -0.47 ~ +0.35V, with an acceptor density 11.21020 cm-3 and a donor density 7.501020 cm-3 respectively. The existence of sulfide in the solution obviously increases the acceptor densities which reaches to 215.61020 cm-3 with the sulfide concentration of 12 mgL1, and therefore have a more conductive behavior.

Abstract: A new unsymmetrical photochromic diarylethene namly 1-(2,4-dimethyl-5- thiazolyl)-2- [(2-methyl-5-(2-pyridyl)-3-thienyl)]perfluorocyclopentene was synthesized, and its photochromic and fluorescent properties were also investigated. The compound exhibited good photochromism both in solution and in PMMA film. In PMMA film, The open-ring isomer of the diarylethene 1 exhibited relatively strong fluorescence at 427 nm when excited at 320 nm. The fluorescence intensity declined along with the photochromism upon irradiation with 297 nm light. Using this dithienylethene 1b as optical storage was performed successfully.

Abstract: A novel photochromic diarylethene, 1-(2-ethyl-benzothiophen-3-yl)-2-(2-methyl-5-(2-cyanophenyl)thien-3-yl)perfluorocyclopentene(1o) was synthesized, and its photochromic and fluorescent properties were investigated. This compound exhibited reversible photochromism, changing from colorless to purle after irradiation with UV light both in solution and in poly-methyl methacrylate (PMMA) amorphous film. Also, it exhibited remarkable fluorescence switching in the solid state. When we used diarylethene 1c/PMMA film as recording medium, rewritable holographic optical storage was performed successfully. The results demonstrated that the diarylethene compound had attractive properties for polarization holographic optical recording, such as high photosensitivity, high spatial resolution, excellent fatigue-resistance.

Abstract: A new workflow technology, which is developed for product design process management (PDPM), is studied in this paper. Firstly, a new product tree structure, which associates workflow with components and solves process-data management problem, is put forward. Secondly, an improved flow structure consisting of workflow and dataflow and being driven by design-parameters is developed. Lastly, Dataflow structure for parameter integration is designed. A PDPM prototype system is developed and applied in engineering.

Abstract: A new unsymmetrical photochromic diarylethene 1-[2,5-dimethyl-3-thienyl]-2-[3,5-difluorophenyl]perfluoroyclopentene (1a) was synthesized, its photochromic, fluorescent and optical strorage properties were examined, the result indicated that the diarylethene 1a changed the color from colorless to purple upon irradiation with 313 nm UV light, in which absorption maxima were observed at 542nm and 556nm in hexane and PMMA film, respectively. This new photochromic system exhibited remarkable fluorescence intensity and clear fluorescent switches by photoirradiation in PMMA film. The results showed that the cyclization/cycloreversion process of the compound was determined to be the zeroth/first order reaction. This new photochromic system also exhibited remarkable optical storage character.

Abstract: This study reports on the Grey relational system, with a statistical experiment to enhance the quality characteristics of yttria stabilized zirconia (ZrO2/8%Y2O3)coatings made by a plasma-sprayed process. The eight control factors were designed in an L18 factorial orthogonal array experiment, and the effects of the control parameters on the surface properties were critically evaluated in the experiments. The characteristic terms- surface roughness, porosity, hardness, and wear volume in the sprayed ZrO2/8%Y2O3 coatings through the optimization- were studied comparatively. A grey relational system, based on the Taguchi orthogonal experiment for optimizing multi-responses in the modified properties, was reported. In addition, the influence of control factors on the grey relational system for spraying processes was investigated by analysis of variance. In addition, a confirmation experiment was conducted. Experimental results have shown that the hardness increased by 31.19%, while the surface roughness decreased by 40.67%, the porosity was reduced by 53.53%, and the wear rate improved by 24.21%. It is clear that the quality characteristics for plasma sprayed coatings are greatly improved through grey relational analysis, and that these findings achieved the desired values in regard to the modified properties.