Advanced Materials Research Vol. 952

Abstract: To improve the anti-wear properties of Mg alloys, Al-13Si, Al-15Si and Al-19Si coatings were prepared by supersonic particles deposition on the surface of ZM5 magnesium alloy. Micro-structure and anti-wear properties of the coatings were examined by digital micro-hardness tester, XRD, friction and abrasion testing machine, three-dimensional microscope and SEM. The results show that the wear-resistant layer and the magnesium substrate can be well integrated as mechanical bonding and the main wear failure mechanism of the three coatings is adhesive wear. Moreover, the micro-hardness of Al-19Si coating is 141.47HV_0.05, much higher than Al-13Si coating (134.97HV_0.05) and Al-15Si coating (136.02HV_0.05). Besides, the anti-wear properties of Al-19Si coating is optimal, superior to Al-15Si coating and Al-13Si coating. All of those indicate that Al-19Si coating can provide the most excellent anti-wear protection for ZM5 magnesium alloy.

Abstract: In constant strain rate tests, the occurrence of dynamic recrystallization (DRX) is traditionally identified from the presence of stress peaks in flow curves. However, not all materials display well-defined peaks when tested under these conditions. It is shown that the onset of DRX can also be identified from the inflection point on the strain hardening rate (θ=dσ/dε)versus flow stress (σ) curve. In this paper, the hot compression curves can be described by an equation that fits the experimental θ-σ data from zero to the peak stress. An appropriate third order equation was fitted to the strain hardening data. The results show that the critical stress at initiation σc=-B/3A where A and B are coefficients of the third order equation. It is evident that this value depends on the deformation conditions. The stress–strain curve was then normalized with respect to the peak stress, leading to a normalized value of the critical stress (u_c) equal to uc=σc/σp=-B'/3A'. Here A'and B'are coefficients of the normalized third order equation. This value is constant and independent of the deformation conditions.

Abstract: Nephelium lappaceum L. peels was effectively used for the synthesis of zinc oxide nanoparticles as a natural ligation agent. The role of rambutan extrac on the formation of zinc oxide nanoparticles was confirmed employing HPLC and GC-MS studies. The XRD and TEM revealed the crystallinity and spherical morphology of the biosynthesized nanoparticles. The size of the particles was found to be 20 nm as deduced from XRD and TEM analysis.

Abstract: Nephelium lappaceum L. peels was effectively used for the synthesis of magnesium oxide nanoparticles as a natural ligation agent. The XRD and SEM revealed the crystallinity and spherical morphology of the biosynthesized nanoparticles. The size of the particles was found to be 60-70 nm as deduced from XRD and SEM analysis. The particle size of as-synthesized magnesium oxide powders measured by PSA was approximately 100 nm. The successful formation of magnesium oxide nanoparticles was confirmed employing XRD, SEM-EDX and PSA analysis.

Abstract: According to the traditional decorative materials of Guizhou Shui Nationality traditional costumes as the starting point, this paper explores the effect of traditional dress decoration materials faced by the current situation as well as new decorative materials development and application of the traditional culture, the conflict and decorations visual effect. Therefore, proposed in the new environment of market economy, it is necessary to make the development and application of dress traditional materials in order to meet the ever-changing market demand, and also to the protection and inheritance of traditional techniques and characteristics of the Shui Nationality decoration visual aesthetic of art and decoration materials contained in the folk culture. The purpose is to express its application value for the diversified development of world culture and art.

Abstract: The decorative materials in Shui national straps art, has strong modeling and regional characteristics. The materials’ visual feature provides creative inspiration to modern landscape design. This paper analyzes the characteristic of these materials, as well as the cultural connotation of Shui national straps art. The design method of indoor and outdoor landscape using decorative materials derived from straps art is proposed. Finally, some typical cases are given to demonstrate the design effectiveness.

Abstract: Traditional subsidence range prediction by stagger angle doesn’t adapt to production situation in deep mining, the angle is usually large. Analyze the lateral support force of the moving bulk solid in the subsidence pit based on maintaining sidewall rock stability of subsidence pit. While bulk solid thickness of subsidence pit is not less than critical bulk solid column, the active pressure and passive pressure of bulk solid prevent the scaling of sidewall rock together. By analyzing the measured data of subsidence range of Xishimen mine, the height of critic bulk solid column relates to stability of rock, sidewall angle of goaf, internal friction angle, and rock loose coefficient. In deep mining, that filling subsidence pit with waste rock can lower the critical depth and control surface subsidence range.

Abstract: The dynamic performance of wind turbine gearbox is very important for measuring the integrated vibration and noise of the whole drivetrain system of wind turbine. The stiffiness and modal parameters of the gearbox will influence the system vibration situation obviously. The wind turbine gearbox is a kind of complicated coupled mechanics; it means the modal analysis on gearbox should consider the coupling effects of the components and define logical damping factors. This paper presents a method to simulate wind turbine gearbox system with the multi-body drivetrain dynamic analysis software. The modal analysis of wind turbine gearbox can be carried out on the basis of the multi-body dynamic theory.

Abstract: For the volume expansive of cement-based materials subjected to sulfate attack, based on microporous mechanics, the model of representative volume element (RVE) is established to analyze the distribution of microcosmic expansive stress in RVE. By homogenization method, the macroscopic equivalent stress of RVE is analyzed. The results show: on the microcosmic scale, the stress of internal sphere in RVE in all directions is compressive, and the radial stress of spherical shell is compressive, but the hoop stress is tensile; on macroscopic scale, the radial equivalent stress is compressive, the hoop equivalent stress is tensile.

Abstract: Established the unsteady oil-film force with rub-impact fault of rotor-stator-bearing system mechanical models by using Lagrange equation, Application of numerical analysis to study it, concluded that the rotor system in frequency as the only incentive system control parameters of orbit and bifurcation diagrams; analysis of the nonlinear behavior of the response of the system and the failure mechanism, provide a theoretical basis for the safe operation of the rotor system and fault diagnosis. The results show that, when the excitation frequency as the only control parameters, the system exist periodic motion, quasi periodic motion and chaotic motion etc abundant nonlinear phenomena.