Advanced Materials Research Vols. 160-162

Abstract: Ceramics composites of B4C matrix with 5 wt% Al and various amount of ZrO2 additives were pressureless sintered under vacuum at 2250 °C for 60 min. Density, hardness, flexural strength and microstructure of the specimens were measured and characterized. Densities above 97% theoretical density (TD) were determined in the samples prepared with the addition of 8 wt% ZrO2 and 5 wt% Al, compared to 86% TD for single-phase B4C. X-ray diffraction analysis showed that B2O3 (impurity in B4C) was eliminated and new phases (ZrB2 and B4C1-x) were formed in the sintered samples, suggesting that in situ reactions between B4C/B2O3 and Al/ZrO2 happened during sintering process. It was showed that the elimination of B2O3 and the forming of boron rich solution of B4C1-x significantly improved the sinterability of B4C matrix ceramics, and consequently enhanced the densification rate greatly. The flexural strength and Vickers hardness of the sintered samples with addition of 8 wt% ZrO2 and 5 wt% Aluminum reached the value of 560 MPa and 30.2 GPa respectively, much higher than those of single-phase B4C ceramics.

Abstract: In aerospace field and submarine field, structure vibration is ubiquity and the work environments is very bad which is oily and work temperature is high. Damping material is a kind of high molecular polymer which has elastic solid property and viscous fluid property at the same time and can attenuate bending vibration of structures and reduce radiated noise. So using damping material to control the structures vibration is an effective method. By experimentations and performance testing of 200 formulas, a new kind of excellent damping material has been successfully developed which is oil resistance and high temperature resistance. At the same time, the paper has established the formula database of damping materials which is a good base for many different engineering applications of damping material with oil resistance and high temperature resistance.

Abstract: High carbon content and addition of other elements, such as Mn in steel, causes some difficulties in the weldability of these materials. In this study, pre and post heating processes were applied for the multipass welded specimens. Tensile test, notch impact test and hardness measurements were carried out, and microstructural features were examined. The weldability of these steels can be improved with the pre and post heat treatments. Maximum hardness values were obtained for the non-heat treated specimens due to large grain structure and high volume percentage of the pearlite content. Although applied heat treatments caused decrease in hardness values, an increase in tensile properties and toughness values at all temperatures occurred. Changes in these properties were explained in the light of the microstructure of the AISI 4042 steel specimens.

Abstract: Amorphous InAsSb films and hydrogenated InAsSb films are deposited on substrates of quartz glass and silicon by rf magnetron sputtering technique in different gas ambient. The effect of H addition on structure, optical properties and electrical properties of a-InAsSb is studied. It is found that the bonded hydrogen content increases with increasing H2 to Ar flow rate radio(R). When R is 0.1, Hydrogen addition shifts the optical absorption edge to higher energy, decreases the dark conductivity and improves the photo-sensitivity. However, hydrogen addition produces the crystallization of the film at R>0.1. Moreover the optical gap, dark conductivity and photo-sensitivity of the films have a reverse change compared with that in R=0. These results demonstrate that hydrogen has obvious passivation effects on rf sputtered amorphous InAsSb thin films only at R=0.1.

Abstract: According to the influence of sintering time, sintering temperature, different amount of flux and different molar ratio of Fe / Sr to the magnetic properties of prepared SrFe12O19 magnetic particles, the optimum SrFe12O19 conditions were concluded. They are: sintering time: 3 hours; sintering temperature: 1073.15 k; flux NaCl amount: 15% wt of the reaction raw materials; Fe / Sr molar ratio: 11.4; the sample magnetic properties: Ms = 63.39emu / g; Mr = 33.44emu / g; Hc = 5798Oe, Mr / Ms = 1 : 1.90 ≈ 1:2. The prepared SrFe12O19 should be single crystal particles and in the shape of flake, and the particle size should be generally about 80-90nm with uniform distribution.

Abstract: A contact-mechanics-based finite model for Cu/ low-k chemical mechanical polishing is presented. 2D axisymmetric quasi-static model for chemical mechanical polishing which includes four-layer structure: Si, low-k, Copper and polishing pad is established. The mechanical response at the interface between the silicon, low-k, copper, and pad is simulated under the loading of the chemical mechanical polishing. The effect of slurry is simplified as the friction force reacted onto both the copper and the polishing pad in the finite element model. Down pressure, status of slurry and the elastic modulus of polishing pad are treated as the parameter in the simulation. Using the model, the effects of applied down pressure, pad properties, status of slurry on the non-uniformity of the wafer surface can be readily evaluated. Simulation results show that the distribution of the Von Mises stresses across a wafer’s surface correlates with experimental removal rate profiles.

Abstract: ZTZL60000/25/45 Automatic End-Advanced Hydraulic Support is developed to meet the needs of the fully mechanized coal face with deep dip angle and large mining height, mechanizing the advanced support of the end and drift, while greatly reducing the construction personnel's labor intensity. Not only the end support strength is enhanced, which improves the safety and reliability of advanced support and generates methods to solve problems related to reserving triangle coal on the face that enhances the support efficiency and reduces support costs, but also more recovered coal resources become available since the height of roadway increases, spawning a certain amount of economic benefits.

Abstract: To combine capillary electrophoresis (CE) and ion mobility spectrometry (IMS) to setup CE-IMS coupling technique, an effective sheathless electrospray interface was developed in the paper. The capillary was rotated on a fixed connector and tapered by manual gridding on the emery paper to obtain tapered capillary tip with the polyimided layer, geometric symmetry. And then the tapered tip was coated with nickel by a simple electrode-less plating procedure to be electrically conductively, so as to generate the electrospray on the tip. Finanlly, three different ways were evaluated for coupling CE with IMS, and get the relatively more effective interface to combine CE and IMS.

Abstract: We report the development and calibration of a built optical magnetic twisting cytometry (OMTC) system. The development includes hardware assembly and software integration. The system has been calibrated in terms of its noise characteristics. The results demonstrated that in current experimental condition the system performed satisfactorily with negligible noise level. The ASM cell also exhibited stiffening in response to mechanical stimulation due to continuous twisting of beads on the cell surface, providing a useful technique for studying the role of ASM cell mechanics in pathogenesis of respiratory disease such as asthma.

Abstract: The ZnO films were deposited on quartz glass substrate by RF magnetron sputtering. The influences of the deposition power, the Ar/O2 ratio and the total press on the crystallinity of ZnO films were analyzed by X-ray diffraction. The results show that the films deposited at Ar/O2 ratio of 2:3 have better crystalline quality under our experimental conditions. The optimum power is about 120-160 W. The crystal structure was significantly influenced by the total pressure in the chamber. The total press should below 1 Pa in order to get high quality ZnO films.