Advanced Materials Research Vols. 217-218

Abstract: The precipitation behaviors of hot rolling and cold rolled annealing steel plates strengthened complexly by titanium and molybdenum were studied in the paper. The microstructures and precipitate phases were analyzed using optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) with energy disperse spectroscopy (EDS). The results showed that the coarsening square TiN phase and the fine roundness (Ti,Mo)C phase were precipitated mostly in the hot rolled steel plate. As the finishing temperature decreased and coiling holding time increased, the quantity of fine precipitates increased. And also the fine round precipitates increased, dispersion expanded and shape of the phase being uniformed as the annealing temperature increased. Therefore, the strengthen effects can be improved effectively by a reasonable control toward titanium and molybdenum precipitation behaviors.

Abstract: the paper puts forward the CDIO-based engineering education mode under college-industry linkage on the basis of the experiences of many Chinese technical schools in this regard. It also elaborates on the syllabus, teaching, laboratory and evaluation of the mode. At last, through case study of college-industry linkage of China’s plastic machinery industry, it proves that the mode is effective to cultivate engineering talents that are most needed in China in a time when the engineering resources are less than needed. The mode can serve as a reference for many developing countries that are sandwiched between the tough choices of cultivating specialists of certain filed or generalists with applicability abroad.

Abstract: This topic takes the miniature Pt resistance strain pressure sensor made by Institute of Electronics, Chinese Academy of Sciences, as the core sensing element, and designs corresponding high-precision, low cost, low power amplifying circuit so as to realize accurate detection of atmospheric pressure in time. In this topic, a new design of amplifying circuit is taken, which first connects the digital potentiometer to the bridge circuit to adjust its balance, and then amplifies the output signal of the bridge circuit once to ideal value. This design not only meets the requirement of measurement, but also is feasible and reduces the cost. At the same time, in order to improve the precision of the potentiometer adjusting the bridge balancing, paralleled resistances are creatively used beside the digital potentiometer and its influence to the bridge balance adjustment and the accuracy of the bridge measurement is analyzed in detail.

Abstract: The speed of chloride penetration caused by cracking at the concrete surface is determined by the crack width. In this study, the impact of the cracks that can occur on the concrete surface (occurring from the contraction during concrete curing) on the chloride penetration speed was revealed through modeling. The accuracy of the established model was also verified through laboratory testing. The definition of the minimum crack width that affects the chloride penetration speed was established, based on testing and consideration of literature. The comparison of crack widths (20, 85, 125μm) based on the chloride profile and model prediction showed that there is virtually no chloride penetration at 20 μm, while the chloride penetration speed increased sharply at crack widths of 85 μm and 125 μm.

Abstract: Based on GA-improved wavelet neural network, this paper explored the Optical Fiber through the establishment of static property 3-dimension compensation model of the optical fiber sensor system. This paper has combined the advantages of both wavelet neural network and genetic algorithm and is thus capable of searching for global optimal solution in the solution space which has very promising application prospect in the areas such as intelligent sensor modeling and compensation.

Abstract: In the course of inspecting and classifying small castings used coal mine, currently the equipment being used has severe limitation that inspection accuracy and classification efficiency is low. With the aid of machine vision recognition technology, the automatic inspection and classification system for small castings developed by author resolved above problems successfully, inspection and classification operation realized automation entirely, inspection accuracy and classification efficiency improved evidently.

Abstract: The modified desulfurized ash is prepared through autoclave curing the desulfurized ash for 6 h at 175.4 oC in the presence of 2.0 wt% Fe2O3 and 0.75 wt% H2O2. In this process, 47.64 % of the calcium sulfite in the desulfurized ash is converted into calcium sulfate. The autoclaved brick is made by 36 wt% modified desulfurized ash, 24 wt% fly ash, 32 wt% sand and 8 wt% stones. The water-solid ratio is 0.10. The compressive strength of the brick is up to 15.7 MPa. For this method, the calcium oxide and calcium sulfate in the modification desulfurized ash are used to replace the lime, gypsum and other materials. The solid wastes are reused and natural resources are saved.

Abstract: In order to overcome the uneven distribution of coir fiber density in the materials and the poor forming of the outer surface, a new type of coir fiber hybrid laminated composites has been developed. The non-woven needle felts of coir fiber are added as the core material, wood veneers are as the surface material, and E-type glass fiber felts are as the reinforcement material, the preparation of hybrid laminated composites has been carried out. Through the performance testing and scanning electron microscopy (SEM) analysis, a new type of biomass composite with excellent performance has been successfully developed. The application of coir fiber to obtain good impact toughness of composites has been effectively verified.

Abstract: Using the flexural vibration method of Fast Fourier Transform (FFT) non-destructive testing, the dynamic MOE of glass fiber reinforced soybean straw particleboard has been determined. The regression analysis among the dynamic MOE, the static MOE and MOR has been done, the significant correlation exists among the three values. And the prediction model has been built, the dynamic MOE can be used to realize the quality assessment by using the model. Using glass fiber to reinforce the soybean straw particleboard, the structure forms and positions of glass fiber have different effects on particleboard performance.

Abstract: Many efforts have been directed to the micro structure and performance evaluation of Electroplated Diamond Film. The indentation method has become extensively utilized in the evaluation of materials’ mechanical. Nano indentation devices, such as MTS-XP, are very useful, but on the other hand, are not affordable for many research institutions. This paper presents an effective and economic method for testing and evaluating micro-cracking performance of Electroplated Diamond Film on Instron 5848 MicroTester by considering the relative hardness values, and the need to evaluate the maximum strength for brittle materials in practical applications. The design of the test system, the evaluation methods, the test results, and the discussions are presented.