Advanced Materials Research Vols. 146-147

Abstract: The crack growth rate test of XCQ16 and XCQ16-1 axle steels were introduced using MTS material test machine. The test data of the crack propagation rate of axle steels has been analyzed by Paris formula. The results showed the crack propagation rate test of XCQ16 was faster than XCQ16-1, and the fatigue residual of XCQ16-1 life is longer. The correlated coefficient of the experimental data indicates that the result of this paper is comparatively ideal and has reference value to appraising the life span.

Abstract: A nucleation-growth control for Al85Ni10Ce5 glass has transformed to a growth control for Al83Ni10Ce5Si2 glass. That’s to say a small quantity of Si addition can successfully separate the Al phase to single precipitate from a eutectic precipitation composited of Al and other intermetallic compound to synthesize nanostructured materials, characteristic of microstructures with finely dispersed nanoccrystalline Al in an amorphous matrix. Favorably，no evident decrease of glass forming ability is observed in the transformation. We suggest that the Si atoms solve into Al lattice to sever as pre-exist nucleus for fcc-Al, in the same time; a nucleation reaction of fcc-Al is accompanied to compensate the nucleation rate.

Abstract: The shear strength characteristics of rock are very concerned in related underground construction. In this paper, in situ direct shear test for the weathered silty mudstone of the direct rock mass in a large section tunnel is carried out, the shear strength parameters are obtained, and some laws on the strength characteristics of this rock are got, such as that the displacement corresponds to the maximum shear stress under the given normal is decreased with increasing of normal loading number. This work provides a reference for the study of rock strength theory and its application.

Abstract: As a kind of flexible fabric reinforced composites, the woven membrane materials suffer from the bi-axial tensile loads in the application of the lightweight structures. Therefore, the experiments under bi-axial tensile loads are essential for the acquaintance of the mechanical characters of the membrane materials. This paper has summarized thoroughly the details of the bi-axial tensile tests, especially the in-plane cruciform tests. The aspects include the shape and configuration of the cruciform sample, the practice of the applied stresses and the testing of the strains in the two axial directions. It could be expected to be the reference for the establishment of the testing standard of the bi-axial tensile experiment for the membrane materials.

Abstract: N2 adsorption-desorption method, scanning electron microscope and transmission electron microscopy were employed to test changes of the specific surface area, average pore diameter and appearances of activated carbons treated with different concentration of sulfuric acid. It can be concluded that these performances altered with sulfuric acid concentration. Activated carbon can be oxidized when the acid concentration increase to a certain value and this process takes time that sulfuric acid molecules first insert in the pore of the carbon which represented by reduction of the specific surface area of carbon and then oxidization occurred. This study is very significant in the development of carbon which is suitable for lead acid battery.

Abstract: This paper discussed fabrication of a very low thermal resistance of thermal interface membrane (TIM). It is assumed that anodic aluminum oxide (AAO) template with silver nanowires inside can function very well as TIM. The TIM was made of well-aligned silver nanowires are expected to reduce the thermal resistance between the heat sink and the electronic device, a chip for example. This work also calculated the pore density, surface area, and porosity of AAO, and thermal conductivity values of AAO with different diameter nanowires inside.

Abstract: Microstructural evolution of a metastable 18Cr12Mn0.55N austenitic stainless steel during compression deformation was investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM observation showed the occurrence of deformation-induced phase transformation and atypical deformation twin, the deformation-induced phase cannot be identified as austenite or martensite. XRD test showed that the amount of deformation-induced phase is less than the detectable limit of XRD.

Abstract: The formability of different gauge tailor welded blanks is difference to single material blanks. As an effective and practical material property test method, tensile test were applied to study it. Base material and tailor welded blanks test specimens had been designed for tensile testing. The results of tensile test indicated that the strength difference and weld line location in the TWBs plays an important role on the formability aspect.

Abstract: Effect of different dosages of PP fibers on cement mortar were studied. PP fibers were modified by Silane Coupling Agent, and the strength of cement mortar was tested. The results show that, compared with unmodified PP fibers, the modified PP fibers can improve the strength of cement mortar more effectively. The microstructure of PP fibers reinforced cement mortar was analyzed by SEM, and the mechanism of modified PP fibers reinforced cement mortar was discussed preliminarily.