Advanced Materials Research Vols. 1061-1062

Abstract: In order to solve the problem of the magnetic property deterioration of the amorphous cores annealed under high absolute water content condition, the deterioration mechanism was studied by using the SEM and X-ray diffraction equipment. The experimental results indicate that the magnetic properties deterioration of the amorphous cores is mainly related with the oxidation of the amorphous cores. It has been found that the oxidation occurred on the surface of the annealed amorphous materials. What’s more, the oxidation formed at the defects of the amorphous materials in priority. Thus the surface quality has a major impact on the oxidation and the magnetic properties deterioration. By analysis of the possibility of the chemical reaction, it is believed that the oxidation is caused by the Fe or B reaction with H₂O. With the holding time increased, the oxides size and quantity increased. To reduce the influence of the H₂O in the air on the magnetic properties deterioration of the amorphous materials during heat treatment, the experiment by aerating the N₂ to the heat treatment furnace was performed. The experiment result proves that the magnetic properties of the amorphous cores were improved during annealing in N₂, which almost reaches the same level of the amorphous cores annealed under low absolute water content condition.

Abstract: The contact of a rigid rough surface and an elastic layered half-space which consists of coating with thickness δ₁ and the substrate. To determine the dependence of the relative contact area on dimensionless the force elastic geometrical parameter , the discrete roughness model presented by microasperities in the form of equal spherical segments with the height distribution corresponding to the bearing profile curve of the real surface is used. By using the stiffness model of layered half-space, the elastic characteristics for every each contacting asperity are determined. The system of transcendental equations which allow to determine the dependence of the relative contact areaη₁ in case of contact through coating layer on the roughness parameters, material properties, coating thickness and applied load is given. The mutual influence of the microasperities is taken into account.

Abstract: Rubber sealing components are significant proportion in evaluation of the storage length for production using it. It is necessary to determine and prolong the storage life of production that evaluated the storage length of rubber sealing components accurately. Based on artificial accelerated thermal ageing tests at five levels of temperature, conclude that the storage length of silicon rubber 3S-60 sealing components would be 11.6 years at 25°C and the confidence level of 95%. Validated this conclusion with nature weathering tests results at Jiangjin exposure field in two years, artificial accelerated thermal ageing tests presented here were available. It was illuminated that the storage length evaluation of rubber sealing components should be testified by nature weathering tests results effectually.

Abstract: Consequences of the wear processes at screws and barrels of injection machines and extruders for processing of plastics reinforced with short glass fibers, arise after a longer time (10,000 cycles). Because of this they are working that through appropriate modeling attempts on the profits to be obtained in a short time as much information relating to both the mechanisms of wear and its size, so that the effect can be easily confuted in practice. Starting from the idea that the greatest pressure and velocity of composite melted is in the die nozzle, was an experimental nozzle with wear samples of sizes and weights which can be measured with precision as good. For a larger accuracy of measurements, we used a method for radiometric measuring, extremely accurate. Different nitriding steels have been studied as nitriding treatments, as well as some special steels and alloyed steels. Besides these, there have been preliminary attempts made to describe and checking corrosive action of termoplastelor on metals. This was another way of checking the wear testing of the samples semi-cylindrical wear samples, which served to simulate the wear of the top layer of the barrel and screw. The first results showed that wear increases depending on the increased pressure. One of the findings is that in similar conditions of injection, with the same content of glass fiber, polyamide 6.6 produces a wear greater than polycarbonate. It was also found that increasing the concentration of glass fibres increase the surfaces wear of barrels and screws.

Abstract: Based on traditional shell-and-tubeheat exchanger, a new heat exchanger which applies to phase change thermal storage was proposed. The thermal storage process of new heat exchanger and shell-and-tube heat exchanger which use paraffin as phase change material and use water as heat-transfer fluid can be simulated by CFD software, respectively. The changes of liquid fraction and heat flux density along with time have been got by computer stimulation. It can be found that maximum heat flux of the new heat exchanger heating wall is 2.5 times than shell-and-tube heat exchanger, melting time of the new heat exchanger is 5 times than shell-and-tube heat exchanger. From the two aspects, the heat storage effect of new heat exchanger is better than conventional concentric tube heat exchanger.

Abstract: The steel fiber reinforced ceramic matrix friction material is prepared by nitrogen protection sintering method. The specimens of the three different friction materials containing different content of alumina, clay and potash feldspar are formulated. The friction and wear characteristics are determined by using the XD-MSM constant speed friction tester. The testing results show that the increase of potash feldspar and the decrease of clay content make friction coefficient become more stable and diminish the sensitivity of friction coefficient to the temperature changes. This study also identify that among the three friction materials investigated, the main wear mechanism converts from grain pull-out and fracture wear to adhesion wear and abrasive wear.

Abstract: Spherical plain bearing is a sliding bearing have a spherical contact surface,it can bear larger load and automatically adjusted to the self-alignin. TiAl-based composite material is a material that be used to lightweight spherical plain bearing. The Simulation used the finite element software Ansys for the bearing’s static analysis.The material of outer ring using normal bearing steel, one group used the TiAl-based composite materials as the material of the inner ring, Another group the inner ring material is bearing steel 9Cr18. The law of the stress and strain produced by the two groups is consistent,the deformation of the composite materials is bigger under the same load, its elasticity modulus and density is smaller compared to the ordinary bearing steel,the composite material has the advantages of high specific strength especially in the occasions have strict requirements of the bearing weight.

Abstract: The deformation of marine water-lubricated stern bearing which the lining materials are polymer materials is much bigger than the bearing built with metal materials. So, in order to improve the calculate accuracy of elastic hydrodynamic, it is necessary to consider the deformation of the lining. Both pressure and thickness distributions of water film which contrasts with the hydrodynamic lubrication are presented by the Reynolds equation, and combining with the elastic deformation of the stern bearing solved by using the finite element method theory. The result shows that the stern bearing water film pressure of elastic hydrodynamic lubrication is lower than that of hydrodynamic lubrication, while the water film thickness is larger.

Abstract: The general characteristic of current plate heat exchangers is first summarized in this paper. A new plate exchanger of multi-stream under high pressure is proposed, which is composed of the plates with opening the gyroidal flow-trough along the radius and the shell, it has some advantages, such as simple structure, high efficiency and available under high pressure. We introduce the structure of the plate, the shell and the slotting types. In addition, the process calculation method of heat-transfer is given and the strength calculation method for the key components of the novel exchanger is also presented. According to the stress analysis to the plate wall with ANSYS software, we have proved the reliability of the calculation method.

Abstract: The temperature and vibration have great influence on the properties and materials of LED luminaires. Therefore, the bi-stress accelerate life testing method under temperature and vibration stress was designed and demonstrated. Based on the large amounts of experimentally obtained data and Arrhenius function, life models of LED luminaires were built rapidly by using mathematical reasoning (least square method and unary linear regression method). The results showed that the method we mentioned can sharply reduce the test life test and the life curve of LED luminaires obey to exponential model.