Advanced Materials Research Vols. 146-147

Abstract: Needle punching geotextile composites are composed of polypropylene woven fabrics and nonwovens, which has lower strength than that of the original woven fabrics because of the damaging effects by needles during the bonding process. In order to compensate for this shortage, a new geotextile composite was developed using adhesive as bonding media, temperature for controlling adhesive bonding effects. So temperature is the most important factor influencing the composites. With the purpose of researching temperature effects on the performance of polypropylene woven fabrics (single layer of the geotextile composite), a series of tests were carried out and then analyzed. The results show that with the increment of temperature, the shrinkage rate of polypropylene woven fabrics increased continuously. On the other hand, the strength firstly rise with the temperature and then decreased when temperature is over 130°C. Conclusions got in the paper are good references for the development of a new kind of water-insoluble adhesive and adhesive bonded nonwoven geotextile composite.

Abstract: The stability is a key product performance index, which can directly determine the quality of the partially stabilized zirconia (PSZ), so how to predict the stability of PSZ accurately, quickly and easily in the preparation process is very important. In this paper, a new mathematical model to predict the stability of PSZ prepared by microwave heating was proposed, based on statistical theory (SLT) and support vector machine (SVM) theory, which relates the stability of PSZ and the influence factors, such as the holding temperature, rising rate of temperature, holding time, decreasing rate of temperature and hardening temperature. Typical data collected from 58 experiments were used for the training samples and test samples. Then testing and analyzing was done. The results showed that the SVM model is reasonable and it is accurate and reliable to predict the stability of the partially stabilized zirconia prepared by microwave heating by SVM model. Besides, multiple influence factors can be comprehensively considered in the SVM model, thus a new highly effective method for predicting the stability of PSZ prepared by microwave heating is provided for future application, which is of great significance to theory and practice.

Abstract: Cu47.5Zr47.5Al5 bulk metallic glasses (BMGs) were cast from the melt temperature 1143 to 1373 K. The structure, thermal and mechanical properties of the BMGs were investigated by XRD, DSC, HRTEM, dilatometric measurements, micro-hardness tests and uniaxial compression. The results indicate that the microstructure and mechanical performance of BMGs are closely affected by the casting temperature. Proper casting temperature ensures the BMGs with large relaxed excess free volume (REFV) and nano-crystallites, which favor the plastic deformation in Cu47.5Zr47.5Al5 BMGs. Regulating the preparing parameters is an important solution to good plasticity in BMGs.

Abstract: Oil consumption of one certain diesel engine has been reduced by optimizing piston structure and piston kids clearance. The oil consumption principle inside the liner of engine was analyzed. Engine test was applied to validate the effect of the optimization. Due to the analysis, enlarge the pressure grads between piston top land and the 2nd land can push the 1st ring to the groove downside steadily. Adding or enlarging oil containing pocket above and below oil ring groove can reduce the oil pressure in these areas. Reasonable and large clearance between piston top land and cylinder liner help the gas burn completely.

Abstract: The corundum based material was prepared, with fused white corundum, commercial SiC powder and superfine Al2O3-SiC powder synthesized from clay by carbothermal reduction reaction as raw materials. The influences of SiC and Al2O3-SiC powders on the slag penetration and corrosion resistance of the material were investigated, and the slag resistance mechanisms of the additives were also discussed. It was found that the slag resistance of the corundum material by adding Al2O3-SiC and SiC powders could be improved obviously. For improving the slag resistance of the corundum material, adding Al2O3-SiC was much better than adding commercial SiC. When the Al2O3-SiC powder contacted with the molten slag, Al2O3 in the additive could be dissolved into the molten slag immediately, while SiC remained, which caused the viscosity of molten slag to be increased. So, the slag penetration and slag corrosion into the corundum material could be effectively inhibited.

Abstract: Apply fuzzy evaluation method to research on running state recognition of mechanical equipment and fault diagnosis, define concept of classification weight of index, give out calculation method. On the basis of analysis of fault datasheet that records expert knowledge, build mathematical model of recognition and evaluation on running condition of mechanical equipment based on uncertainty measurement. Calculation examples show the effectiveness of this method and the reliability of calculation results.

Abstract: The effects of the hydrocarbon chains and spacer groups of a series of sulfate anion Gemini surfactants(Cm-s-m.2Na+) on the rheological behavior are investigated in this paper. Results show that either length of carbon chain increases or length of linking group decreases, solution viscosity increases, C12-2-12.2Na+ has the best viscosifying ability. Then variation of viscosity of C12-2-12.2Na+ solution with concentration, pH, shear rate, temperature, and hydrolyzed polyacrylamide (HPAM) are observed. Results indicate that viscosity increases as concentration increases; single-chain cationic surfactants make viscosity increases first then decreases; concentration of multivalent ion increases or temperature raises or shear rate increases, corresponding viscosity decreases; while pH increases, corresponding viscosity rises first and decreases later; HPAM can enhance the viscosity of C12-2-12. 2Na+ solution, showing that gemini surfactant has a good synergism with HPAM.

Abstract: On the investigations on the flexural properties,color stability and melting properties,the effects of treating ramie fiber with silane coupling agent on the anti-thermo-oxidative aging properties of high density polyethylene(HDPE)/ ramie fiber composites were studied.The results show that,treating the fiber with 3% coupling agent can improve the flexural strength and modulus of the composites before the aging test by 15.9% and 21.7% respectively,and also it can improve the flexural properties of the composites after the aging test;the modified composites will be more color stable,less color difference,and less disminish of the color during the aging test;the peak melting temperatures of the modified composites when aged for 0,500,1000,1500 and 3000h will be increased by 0.6，0.2， 0.5,2.3 and 3.8 oC from those of the unmodified composites;the flexural properties,color stability and melting properties of HDPE / ramie fiber composites during thermo-oxidative aging tests all indicate that treating ramie fiber with coupling agent can improve the anti-thermo-oxidative properties of the composites.

Abstract: The synthetic leather base is a composite, with the top and lower layers are nonwovens and the middle is woven fabrics. Firstly, the single rip tearing strength and drawing out resistances of the leather base were tested and tearing failure mechanics were analyzed. Then on the above basis, the single rip tearing strength calculation model of the synthetic leather base was built successfully. From theoretical model, main influencing factors are the weft and warp yarn breaking strength and the density of warp and weft yarns in the woven fabric, and also drawing out resistance of the leather base. Finally, experimental verification was made for the established model, which shows that theoretical values conform to the measured values well.

Abstract: Aniline was polymerized on the surface of LiFePO4 particles by in-situ polymerization technique, forming LiFePO4/polyaniline composites. The composites were characterized by Thermo gravimetric analysis, specific surface area tests, high resolution transmission electron microscopy observation. The specific capacity, rate capability and cycling stability of composites were studied by charge-discharge tests. The experimental results show that the LiFePO4/polyaniline composite containing 6.75% polyaniline possesses the best electrochemical properties. Its initial capacity reaches 151.97 mAh.g-1 at C/10 rate, its cycling stability is excellent, its specific capacity is 124.89 mAh.g-1 at 1 C rate, its capacity loss is only 17.82% when rate increased from C/10 to 1 C.