Abstract: Gd-doped AlN film was deposited on Si (222) substrate by Radio frequency reactive sputtering. XRD patterns show that the Gd-doped film maintains the hexagonal wurtzite structure with the (002) preferred c-axis orientation. The deposition film possesses similar smooth surface and homogenous grain size. A broad emission band centered at 444nm is observed and the band could be ascribed to the defects. The results show that Gd is a potential dopant for preparing magneto-electrical devices operating at room temperature.
Abstract: The variation rules of strength with the microstructure and precipitates of container steel were studied by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the microstructures of four kinds of test steels are all bainite and M/A island, but the number and size of islands of M/A and precipitates exist obvious difference: two kinds of test steels have fewer precipitates and more M/A islands, however, the other two kinds of steels are on the contrary. As for the former two kinds steels, the number of M/A islands is larger, and the size is smaller, the strength of steel is higher; For the later two kinds steels, the number of precipitates less than 30nm is larger, and distribution is more uniform dispersion, the strength is higher, precipitation strengthening effect is better. Getting lots of small and uniform M/A islands or precipitates is an effective way of improving the performance of steel.
Abstract: Developing steady state models to conduct and control repeatable processes of low-pressure nitriding is not possible in practice as the nitrogen content in a nitrided layer depends not only on the nitriding parameters, but also on the content of alloying elements in steel and the nucleation stage which is difficult to control. Therefore, a new concept of conducting such processes has been proposed. It has been shown that application of an appropriate method of activation of steel parts surface makes the nucleation stage uniform and reduces its duration. A system based on artificial intelligence methods has also been proposed, which enables modelling and control of non-equilibrium processes of low-pressure nitriding of tool steels. This model is based on the “boost-diffusion” schedule of the process.
Abstract: The kinetics parameters in the leaching of polyphenol from Arctium lappal root was studyed in this paper. According to second Fick’s law of diffusion, the kinetic equation for polyphenol leaching process was established with ball model. The results can provide the valuable theory basis for the technical design and further research of polyphenol from Arctium lappal root leaching process.
Abstract: When diagnosing sudden mechanical failure, in order to make the result of classification more accurate, in this article we describe an affinity propagation clustering algorithm for feature selection of sudden machinery failure diagnosis. General methods of feature selection select features by reducing dimension of the features, at the same time changing the data in the feature space, which would result in incorrect answer to the diagnosis. While affinity propagation method is based on measuring similarity between features whereby redundancy therein is removed, and selecting the exemplar subset of features, while doesn't change the data in the feature space. After testing on clustering and taking the result of PCA and affinity propagation clustering as input of a same SVM classifier, we get the conclusion that the latter has lower error than the former.
Abstract: The influence of residual stress and sensitizing on the electrochemical and corrosion behavior of type SUS304 stainless steels weldment has been studied in the Freeze-Thaw condition. After immersion test at Freeze-Thaw cyclic condition the severe corrosion damage was detected in the vicinity of weld boundary more than isothermal condition. The corrosion damaged zone corresponds to the location in which there are high residual stress and sensitization. The influence of residual stress and sensitization was distinguished and its magnitude was evaluated by voltammetry method.
Abstract: The machining accuracy is greatly affected by the precision of mechanical transmission of the NC machine. Through analyzing the nonlinear factors of mechanical transmission components of the NC machine, the reasons for affecting the positioning accuracy and the contour- following accuracy are obtained. Therefore the methods of improving the positioning accuracy and the contour- following accuracy are put forward.
Abstract: The article focuses at technology development of the vertical asymmetric rolling and combined process of vertical asymmetric rolling and plastic bending. It has been shown that vertical asymmetric rolling peculiarity relates to the presence of a mixed zone, in which friction forces on contact roll surfaces are directed are differently. Experimental research showed serious drawbacks in the rolling technology caused by the growth of dynamic loads arising at the moment of plate contact with the bending roller. For solving the problem it was proposed to make the roller position motile to allow its movement along the required trajectory. The application of the motile roller helps to reduce dangerous torque differentiation at working rolls by the value of 1,5-2,5 compared with the rigidly fixed roller. The most effective bending roller trajectory is a second-order curve that is convex parabola.
Abstract: Laser processing ceramic materials is a new application of laser technique. This paper presents the study of laser processing parameters of glaze cladding. It found out that the parameters of laser processing affected the morphology of glaze cladding significantly. Within the experimental conditions, rise of output power or drop of processing speed can increase the depth of melted zone and the width of glaze cladding, vice versa.
Abstract: To assure the safety of the power bogies for train, it is important to perform the durability analysis of reduction gear considering a variation of velocity and traction motor capability. In this study, two types of applied load histories were constructed from driving histories considering the tractive effort and the train running curves by using dynamic analysis software (MSC.ADAMS). Moreover, this study was performed by evaluating fatigue damage of the reduction gears for rolling stock using durability analysis software (MSC.FATIGUE). The finite element model for evaluating the carburizing effect on the gear surface was used for predicting the fatigue life of the gears. The results showed that the fatigue life of the reduction gear would decrease with an increasing numbers of stops at station.