Advanced Materials Research Vols. 152-153

Abstract: This paper applies the sol-gel method (Sol-Gel) ，uses Poly Vinyl pyrrolidone (PVP) as dispersant，oleic acid as modifier to prepare and modify micro/nano-MgO particles. The characterization results of micro/nano-MgO particles by using XRD and SEM verified that micro/nano-MgO particles prepared above are FCC and the average particles size is 50nm. In the process of friction and wear experiment, the results show that at the significant effect of anti-friction and anti-wear is obtained after adding micro/nano-MgO particles in the 4012 marine lubricant. Especially under higher loads, the friction-reducing effect is more prominent.

Abstract: The interation between aniline and shenfu-coal(SFC) was studied by the changes about acidic functional groups and the absence of coal macromolecules. The results showed that the acid content in coal is increased by HNO3, the conductivity of OCPANI, HNO3-OCEX-PANI, as well as SFCEX-PANI is lower than SFC-PANI. The macromolecular structure of the SFC play an important role,the macromolecular acid in coal only play the weak doping role.

Abstract: The development of adding optical functionality to a silicon microelectronic chip is still a great challenge in material research area. Silicon and its oxide are not luminescent for they do not possess direct electronic band transition. Here we demonstrate that room-temperature photoluminescence (PL) has been observed from silicon/silicon dioxide laser sintered body with its strongest PL intensity peak being at 387 nm (3.20 eV) and another peaked near 788 nm (1.60 eV). The effects of silicon/silicon oxide particle diameters and silicon contents on room-temperature PL of their laser co-sintering samples were studied. It was found that the PL peak intensity changes with the increasing silicon content.

Abstract: Phenolic resin was used as the raw material, formed a mold for complex-shaped component by rapid-prototyping. It was composed of SiC, C and Si. The sample hardness was analyzed through statistical comparison. The phase composition of C/SiC composite was investigated by XRD and microstructures of C/SiC ceramic components were observed with scaning electron microscope. The ceramic components obtained at 1500 by reactive infiltration of Si into porous C-template. The porous structure formed by photecurable resin and starch powders pyrolysis could effectively prevent the C-template from cracking and reduce the stress. It also facilitate penetrating Si to the C-template to form SiC.

Abstract: By means of a tensile instrument and SEM, the mechanical property parameters of HTPB propellant test samples with different formulas were tested, and their microscopic fracture cross section patterns were observed. Take advantage of these testing results, the relationship between microscopic structure and mechanical properties of HTPB propellant was studied. The results show that the mechanical properties of a propellant are closely related to its microscpic structure state. The structural integrity of propellant is mainly influenced by the bond effect of the interface between binder and solid particles, solid particle’s shape, size and its distribution, the content of binder matrix, etc. These factors have important effects on the mechanical properties of propellant.

Abstract: 3D braided group theory is dissertated. The analysis procedure is described from the existing braided geometry structure to the braided space group; 3D braided geometrical structures are finally described by means of group theory. Some of novel 3D braided structures are deduced from the braided space groups. By describing the 3D braided materials with braided space point and braided space groups, the braided space groups are not always the same as symmetry groups of crystallographic because novel lattices can be produced and the reflection operation cannot exist in braided space point groups. Braided point and space groups are theoretical basis for deriving the novel braided geometry structure.

Abstract: The electrochemical compatibility between natural graphite and garnet-like Li6BaLa2Ta2O12 or organic electrolytes was investigated. The formation of solid electrolyte interface (SEI) films in the initial cycle was investigated by galvanostatic charge and discharge, cyclic voltammetry experiments. The experimental results show that electrochemical compatibility between natural graphite and Li6BaLa2Ta2O12 is the most excellent, while electrochemical compatibility between natural graphite and PC-based electrolytes are the poorest. In the initial cycle, the discharge capacity and charge-discharge efficiency are both the highest in Li6BaLa2Ta2O12 electrolyte, and they are 337.1 mAhg-1 and 99.5 %, respectively.

Abstract: Based on nonlinear finite element method, the character of expressway widened engineering reinforced with geotextile is studied. It is found that the main vertical settlement, lateral displacement and failure surface of embankment occurred in the widened part of embankment. The lateral displacement decreased, the total incremental of displacement reduced and the stability of embankment enhanced when expressway widened engineering reinforced with geotextile. It also can be found that the axial force of geotextile get its maximal value at the intersection of old and new part of embankment, which is controlled by the differential settlement and normal stress mainly. In order to reinforce the embankment effectively, it is advised that the geotextile should be paved on high-stress zone.

Abstract: Basing on the performances analysis of the expandable tube material, the paper introduces the FMA multiphase alloy steel, the new type of expandable material. The conclusions were presented at the detailed analysis of material microstructure, chemical composition, heat treatment, mechanical properties and other aspects. This paper will promote the application of this new material.

Abstract: To improve the application of the new proto-machine-made sand in structural engineering, tests are carried out to study the drying shrinkage of concrete affected by stone powder in proto- machine-made sand. The target cubic compressive strength of concrete is 55 MPa, the main factor varied in mix proportion of concrete is the contents of stone powder by mass of proto-machine-made sand from 3 % to 16 %. The drying shrinkage strains of concrete are measured by the standard method at the ages of 1 d, 3 d, 7 d, 14 d, 28 d, 60 d, 90 d, 120 d, 150 d and 180 d. Based on test results, the drying shrinkage of concrete affected by the contents of stone powder in proto-machine-made sand is analyzed and compared with that of similar test of concrete with traditional machine-made sand, which shows that there is the optimum content of stone powder resulting in the lower drying shrinkage of concrete. The formula for predicting drying shrinkage strain of concrete is proposed.