Advanced Materials Research Vols. 482-484

Abstract: In order to find out the feasibility to obtain dynamics peculiarity in high frequency domain, the dynamic peculiarity on detecting method with strain gages is researched. By modeling and analyzing qualitatively, the characteristics of low frequency are indicated for strain gages sensor system. Comparing with the test signal difference between vibration acceleration sensor and strain gages sensor system at the three domain which are time, amplitude and frequency, the characteristics of low frequency are proved for the one. Therefore while detecting the high frequency dynamic signal with strain gages sensor system, the high frequency information is attenuated, the mostly spectrum information is lost.

Abstract: This research compares the difference in determining the austenite amount in SKD 11 tool steel using the micrographic method as opposed to the X-ray diffraction method. Calculating the amount of retained austenite in tool steel using X-ray diffraction analysis requires first taking off the primary carbide content. By etching the SKD11 specimen using Beraha’s CdS reagent, the retained austenite, martensite and carbide are shown as white, red and blue regions in the microstructure, respectively. With quantitative metallography, the retained austenite can be distinguished as separate micro-constituents and properly counted. However, the calculated values are lower than those acquired from the X-ray diffraction. It is more accurate to evaluate the amount of retained austenite with carbide by X-ray diffraction analysis.

Abstract: Based on the fracture mechanics theory and fracture surface topography analysis (FRASTA) method, the interior fracture property of a bearing steel in very high cycle regime was studied by means of rotary bending fatigue test. As a result, this bearing steel represents the duplex S-N curves characteristic, where the interior inclusion-induced fracture is the predominant fracture mode in very high cycle regime. The rough granular bright facet (GBF) area corresponding to smaller inclusion is usually formed in the lifetime larger than 106 cycles, whose formation progress can be interpreted as the slow crack nucleation based on decohesion of spherical carbide from the matrix. The fatigue property in the fish-eye region outside of GBF can be interpreted as the stable crack propagation progress and that outside of fish-eye is instable crack propagation progress. The stress intensity factor ranges of GBF and fish-eye, ΔKGBF and ΔKfish-eye, can be regarded as the threshold values of controlling stable propagation and instable propagation of interior crack, respectively.

Abstract: The effects of voids on the longitude tensile strength of T300/914 laminates that exposed to room temperature, hygrothermal and drying environment was discussed in this paper. The experimental results reveal that the saturated moisture content and the rate of water uptake increase with porosity increasing from 0.33% to 1.50%, which proves that voids facilitate moisture absorption. The tensile strength of non-aged specimens decreased 2.36% with the porosity increasing from 0.33% to 1.50%. Compared to non-aged specimens, the tensile strength of aged specimens decreased 5.15%, 5.34% and 7.59% with porosity of 0.33%, 0.71% and 1.50%, respectively. The tensile strength of dried specimens is higher than that of the aged specimens and is lower than that of non-aged specimens in the case of similar porosity.

Abstract: A new and easy-to-prepare, surfactant-based polymer-free fluid, CTAB-SA, consists of etradecyl trimethyl ammonium bromide, cetyl trimethyl ammonium bromide and octadecyl trimethyl ammonium bromide with salicylic acid is described. The properties as a fracturing fluid were evaluated with regard to viscoelasticity and proppant carrying capability. The results showed that these water gels have strong proppant-carrying capacity and high viscoelasticity, and the best performance was obtained from the gels derived from octadecyl trimethyl ammonium bromide with salicylic acid. The viscoelasticity of these gels were increase with the quality ratio of ammonium bromide to acid.

Abstract: The error compensation is an essential issue for improving the accuracy of the machining process. To solve the error compensation for parallel grinding of the noncoaxial aspheric lens, a kinematics model of six-axis ultra-precision machining system has been developed in the present study. Based on the theory of multi-body system, a kinematics errors analysis is presented. The interpolation errors of the parallel grinding method are discussed according to the kinematics errors analysis. Simulation results show that the rotation errors of the grinding system are crucial factors affecting the accuracy of the machining process.

Abstract: The theoretical and experimental work is executed for study the impact of anneal on the grain size, electromigration (EM) reliability of copper (Cu) interconnect system, and subsequently find the optimized anneal condition. EM accelerated failure tests are carried on the Cu interconnect samples with 0.2μm line width, which are produced at different anneal conditions. It is shown that anneal can lead the grains to grow to become larger, and lessen the EM diffuse path. As a result, the EM diffuse active energy (Ea) of Cu interconnect is enhanced, and the ability against the EM of Cu interconnect is improved. By comparing the EM character of Cu interconnects produced at different anneal conditions, results can be obtained as below: the anneal time should be maintained 40 minutes at least in order to achieve fully anneal and excellent ability against the EM; the anneal temperature should be set about 350°C approximately, because high temperature (beyond 400°C) anneal can induce the other reliability issues, which will have a strong negative impact on the EM reliability. The results in this paper are significance for Cu interconnect technology optimize and are beneficial to improve the EM reliability of the Cu interconnect system.

Abstract: Silane treatment is a new method of coating pretreatment, its mechanism, process, traits and problems in the applications were studied. Compared with the traditional phosphating treatment, silane treatment has the characteristics of non-pollution, simple operation, energy saving and environmental protection, and can substitute for the phosphating treatment and has a great development potential.

Abstract: The cam pumps are especially suitable for the transmission of the liquids with different impurities or pure solid materials. A new design method for the rotor profile curve of the cam pump was put forward to improve the wear-proof of the addendum of the rotors. A rotor with a simple profile curve was designed and then the profile curve of another rotor would be generated by a tool whose cutting profile curve was the same as the designed rotor profile curve. This method was stated and a mathematic model was built based on gear meshing theory by choosing an ellipse as the designed rotor profile curve. The influence of the design parameters on the generated rotor profile curve, the area utilization coefficient of the pump and the relative normal curvature of the two profile curves at the contact points were analyzed. The results demonstrated as: the designed profile curve can be some kind of simple continuous curve and the generated profile curve is continuous curve as well; the area utilization coefficient, C, increases by increasing the major semi-axis of the ellipse, a, or decreasing the minor semi-axis, b, if the designed profile surface is an elliptic one; the maximum of the area utilization coefficient, Cmax, will decrease when the blade number of the rotor 2, z2, increases because of the undercutting; the maximum of the area utilization coefficient is 0.48 when z2 is 2; the blade number of the rotor 2 is no more than 4.

Abstract: Hydroxyiron-vermiculite complexes (Fe-Vermiculite) were prepared and identified using X-ray diffraction (XRD). The surface properties and selenate adsorption characteristics of Fe-Vermiculite were investigated. The specific surface area, surface fractal dimension D value and the pH value of the point of zero charge (pHPZC) of vermiculite were 287.19 m2/g, 2.14, and 2.87, respectively, and those of Fe-Vermiculite were 312.48 m2/g, 2.59, and 5.74, respectively. At pH 5.5, the maximum adsorption capacities (qmax) for selenate of vermiculite and Fe-Vermiculite were 4.36 and 9.12 mg/g, respectively. Langmuir isotherm was very suitable for describing the selenate adsorption of vermiculite (R2 =0.993), and Freundlich isotherm could fit the adsorption data for selenate by Fe-Vermiculite (R2 =0.981).