Advanced Materials Research Vols. 415-417

Abstract: The influence of different types of compatibilizers on property improvement of the CENR/PP TPVs was investigated. The compatibilized TPVs exhibited superior tensile and dynamic-viscoelastic properties as well as better phase morphology than those of the uncompatibilized TPV. This contributed to compatibilizer reduced the interfacial tension and enhanced the interfacial adhesion between the phase boundaries. In this study, we found that the PP-g-Ph compatibilizer provided the CENR/PP TPVs with the best overall properties.

Abstract: Removed due to double publication.

Abstract: In this paper we designed several different embedding ways of making sensing fabric using CCFs compound yarns, observed the relationship of resistance and elongation through fabric tensile test, and analyzed its sensitivity, linearity and resistance change stability of the fabric according to regression model. Research shows that: in terms of conductive fabrics embedded with CCFs compound yarns, the more the number of CCFs compound yarns embedded, the lower its sensitivity is and the better its repeatability and the fabric’s stability with respect to resistance change would be. Among all conductive fabrics embedded in different ways with the same quantity of compound yarns, the samples embedded continuously have the lowest sensitivity, but it has the best resistance change stability and repeatability.

Abstract: Corrosion of tungsten in molten aluminum was investigated by static immersion tests at 700, 750 and 800°C temperature for 8-120 h. In all cases, the Al3W intermetallic compound was formed. The intermetallic layer broke up as long as it grew due to thermal stresses and dispersed in the molten aluminum. The weight-loss of tungsten varied linearly with time. The corrosion rate increased with temperature and the activation energy was nearly 87.92 kJ mol^-1.

Abstract: In-depth study of compressible material constitutive equation, using incompressible condition, the nonlinear incompressible elastic solid’s complete irreducible constitutive equation and strain energy function expressed in invariants are derived in this essay. The elastic constants of rubber material are given by fitting the experiment data that was carried out by Treloar with the equation. Then we got evelen exact value of the elastic constants.

Abstract: Two mechanisms about electrochemical modification of clay minerals are summarized: one of electroosmotic dewatering and stabilization and the other of cation substitutions, structures and properties change, forming new minerals. The analyses of physicochemical soft rock (PCSR) indicate that physicochemical property of PCSR is dominated by physicochemical property of clay minerals. Therefore, it is possible to indurate PCSR in the coal-mine soft rock roadway with the electrochemical method.

Abstract: Since it is difficult to cut off large specimens from nuclear piping, generally the standard CT specimens of 1T are used to perform fracture toughness tests. However, when compared with the test result obtained from a real pipe, the results from CT specimens are been known to be very conservative. Therefore, the U.S. Nuclear Regulatory Commission recommends the use of specimens whose thickness is greater than or equal to the thickness of a real pipe for estimating the stability of crack resistance[1]. In this study, a series of fracture toughness tests were performed using various types of specimens: the standard CT, non-standard Compact Pipe, and Curved CT. The results of the tests were compared.

Abstract: Based on the density functional theory, the plane-wave pseudo-potential method is performed to investigate the structural properties of α-Si₃N₄. The ground-state lattice parameters (i.e. lattice constants and cell volume) agree quite well with the experimental data. From the band structure calculation, we found that the stability of α-Si₃N₄ is due mainly to the interaction among the Si-s, Si-p and N-p states. The imaginary part of the dielectric function has a sharp peak at 8.2eV. For the real part of the dielectric function, the highest peak locates at 6.5eV. Our calculated results are in good agreement with the experimental data and previous theoretical values. Therefore, the calculated results may provide useful information for further investigations of α-Si₃N₄.

Abstract: A polymer drilling fluid containing high content of hydrogen sulfide was used as the corrosive medium to investigate the effects of temperature, flow velocity, pH value and partial pressure ratio of CO₂/ H₂S on the corrosion behavior of high strength drill pipe steel S135 and G105. The morphology and composition of the corrosion products were analyzed as well. It was found that the average corrosion rate of the two types of steel increased with increasing temperature of the corrosive medium, with the corrosion rate to decrease slightly within 60°C-80°C and keep almost unchanged above 120°C. At the same time, the corrosion rate of the drill pipe steels had little to do with the flow rate but increased with decreasing pH value of the corrosive medium. Moreover, the partial pressure ratio of CO₂/ H₂S had a slight effect on the corrosion behavior of the drill pipe steel. However, the two types of drill pipe steel showed a larger corrosion rate in gas phase than in liquid phase corrosive medium, which was contrary to what were observed in gas and liquid phases corrosion tests of conventional acidic drilling fluids. In addition, it was confirmed by sulfide stress corrosion test that the drill pipe steel of a higher strength had smaller critical stress, and the resistance of the drill pipe to stress attack was ranked as G105(C)＞G105(D)＞S135(B)＞S135(A). It was anticipated that the present research results could be used to guide the selection of materials for drilling pipe steels used in natural gas field of high acidity.

Abstract: Rubber shock absorbers are the key parts to isolate vibrations of the machinery and equipment. In this paper, a three dimensional finite element model of a rubber shock absorber is established; then the computation of three dimensional fatigue crack growth rates are discussed by using the nonlinear finite element method. The stress distribution which can determine the initial crack location and the possible risk surface under dynamic loads is obtained. The three dimensional crack growth is simulated by using finite element method and linear elastic fracture mechanics. A brittle fracture process of the rubber shock absorber along the dangerous surface is simulated by using the cohesive element of ABAQUS.