Applied Mechanics and Materials Vols. 496-500

Abstract: IR-spectroscopy is an essential tool for the study of the structural features of the material, regardless of its state (amorphous or crystalline). It allows accurately explain the type and character of structural bonds, the presence of certain molecular groups in the material. For the construction material science, this analytic method helps to study raw materials and composite materials, binders, etc.

Abstract: Under the background that solid wastes have been produced and increased continuously, how to change waste into treasure has become an important research topic to achieve sustainable development. Based on a cooperating project with an enterprise, the production technology and key equipments for ceramsite produced from coal fly ash and clay have been studied which is of great significance not only to carry out the industrial solid waste disposal and make best use of resource but also to guide the running of the production line.

Abstract: Carbon blacks are used universally as fillers in polymer matrix for mechanical, electronical and thermal properties improvement. Plenty of studies show that the structure and surface properties affect the function of carbon blacks in polymer matrix intensively. However, the reinforcing mechanism is still controversial. In this study, we studied the structure of three carbon blacks by Dibutyl phthalate (DBP) absorption and atomic force microscopy (AFM) and analyzed the absorption/desorption forces of the three carbon blacks surface by force-distance curves. The results show that the carbon black with relatively high structure possesses more branches and bigger aggregation morphologies and shows the highest surface absorption/desorption forces, which may increase the reaction between carbon black and polymer matrix.

Abstract: The7A05 aluminum alloy of the 10mm thickness was welded by the friction stir welding. The microstructure and mechanical Properties of the welded joint was researched by the optical microscope, etc. The results showed: the microstructure of the weld nugget zone and the thermal mechanically affected zone were refined as the welding speed increasing when the rotate speed is constant. As the welding speed increasing the strength of extension of the welded joint is increasing at first and then stable basically. but the yield strength had no obvious change.

Abstract: Silk floss was deoiled with leaching Method using 6# light gasoline in order to improve wearability of silk floss. The effect of temperature, time and bath ratio on the oil removal efficiency was studied by single factor analysis method. The results showed that the optimum degreasing technologies of silk floss with 6# light gasoline are: bath ratio 1:30, treatment time 40 min, and treatment temperature 50 °C. Under the optimum degreasing technologies of silk floss, the residual oil ratio of silk floss is 0.01% which is far below national standard.

Abstract: The Microstructure Evolution of Mg-14Li-Al and Mg-14Li-Al-0.3%La (wt.%) is Investigated. The Results Show that, the Precipitation of Al2la is Specially Dissolved in Mg-14Li-Al-0.3%La Alloy which Soft Texture and Decrease the Tensile Strength through SEM (Scanning Electron Microscope) Images. Through the Stress-Strain Testing, the Fracture Morphology is Observed. It is Suggested that the the Direction between Texture and Dislocation Movement is the Dominant Factor Influencing Ultimate Tensile Strength and Yield Strength for Mg-14Li-Al-0.3%La Alloy. In Conclusion, adding Miner La Element in Magnesium Leads to Excellent Metal Forming.

Abstract: PVP/[Sr (NO₃)₂+Mg (NO₃)₂+TEOS+Eu (NO₃)₂+Dy (NO₃)₂] composite nanofibers were prepared via electrospinning, the effect of different electrospinning parameters on the composite nanofibers morphology were investigated. The results revealed that diameter of the composite nanofibers increased at first and then decreased with the increasing of voltage, and the properties of the spinning solution (viscosity and surface tension) increased gradually, but the conductivity decreased at first and then increased with the increasing of PVP content. SEM analysis indicated that its easy to get a good morphological and uniform composite nanofibers when the voltage was 13 ~ 15 kv, inorganic salt content was 5% ~ 6%, and concentration of PVP was 15%.

Abstract: Laser peen forming, is a purely mechanical forming method achieved through the use of laser energy to form metal plate with small curvatures. Experiments were performed to investigate the effect of pre-bending on the plate bending deformation induced by laser peen forming. The pre-bending of plate was accomplished by a fixture with the cambered top surface. The pre-bending curvature radius is calculated and is used to design cambered surface. The LPF experiments are performed with Nd: YAG laser with overlapping laser spots. It is found that the convex deformation can be induced after laser shocks. And its curvature radius in the elastically elongated direction can be greatly increased by applying pre-bending, while in the perpendicular direction, the curvature radius is decreased.

Abstract: Powdery emulsion explosive (PEE) invented by Ouqi Ni at the end of 1980s is a new kind of W/O industrial explosives. It has brought industrial explosives technology into a new era. Through years of development, Model I powdery emulsion explosive has been put into large scale production in more than 70 explosive manufacturers and is widely praised by its users. Through continuous research and improvements, Model II powdery emulsion explosive with better performance, longer shelf life and considerably lower cost has been successful invented. Given that safety is one of the most important factor in production, transportation and usage of industrial explosive, this paper is to evaluate the safeness of Model II PEE in terms of mechanical sensitivity, heat sensitivity, static electricity safety, and dust explosion risks. The testing results showed Model II PEE has achieved excellent safety level.

Abstract: The propagation rate of low cycle fatigue and life expectancy for stiffened plates are analyzed by using local average strain amplitude at crack tip as the basic parameter. The crack propagation is considered as the result of local material separation in the plastic zone of crack tip, which is not a continuous process but an intermittent alternating process of strain accumulation. From the point of view, the analysis is performed and the results are well compared with those from Finite element method.