Applied Mechanics and Materials Vols. 475-476

Abstract: The prospects of the use of rolled shapes made of high-strength steels in steel structural elements are considered. A comparative analysis of strength values and economic indices of steel structural elements is done for their work in compression, tension and bending.

Abstract: Use relaxor ferroelectric single crystals PMNT as piezoelectric phase, epoxy resin as a non-piezoelectric phase material, take the cutting - filling method fabricated piezoelectric composite. Its structure character is achieved 1-3 type piezoelectric composites and piezoelectric crystal substrate composite again inseries by the integration, the composite horizontal and vertical bracket to be supported by piezoelectric crystal frame, it has a good impact resistance and affected by changes in ambient temperature characteristics. This composite material both has the advantages of 1-3 type composites, and has stable mechanical and thermal properties. Based on R.E.Newnhams series-parallel theory, combined with the structural characteristics of this composite, given the formula of piezoelectric composites density, piezoelectric constant, and dielectric constant. Fabricated the PMNT / epoxy composites and piezoelectric PZT / epoxy piezoelectric composite materials samples, which have the same scale, the same structural parameters. The experimental results show that, the piezoelectric composite test parameter values match theoretical calculations. The PMNT/epoxy composite has batter function than PZT/epoxy composite.

Abstract: In this paper, red phosphorous (RP) was coated by aluminum hydroxide to prepare modified RP (MRP). MPR was blended with high density polyethylene (HDPE) to obtain MRP/HDPE composites. And the properties of MRP/HDPE composites were investigated. The effects of MRP on the flame retardancy, thermal decomposition behavior and mechanical properties of HDPE were also discussed.

Abstract: Nanocrystalline VO_x thin films were manufactured by using pulsed laser deposition. The influence of deposition time on electrical parameters of VO_x thin films were researched. It was determined that changes in deposition time lead to significant changes in properties of thin films, including resistivity in the range from 5 Ohm·cm to 70 Ohm·cm. The possibility of controlling physical properties of VO_x nanocrystalline films obtained in the experiments has been shown.

Abstract: An improved TPD-IR technique was developed recently. By which means, acid properties of Brønsted acid sites on HY zeolite and SAPO-34 zeolite were studied by an advanced TPD-IR technique with ammonia as probe molecule. Desorption activation energy (DAE) of the probe molecule adsorbed on zeolite was used as a measure of the acid strength. The result indicates the Brønsted acid sites of HY Zeolite or SAPO-34 zeolite were divided into two types with the strength of DAE of ammonia 43.4KJ/mol, 24.4KJ/mol and 33.2KJ/mol, 20.5KJ/mol. It is concluded that HY zeolite has the stronger Brønsted acid sites than that of SAPO-34 zeolite.

Abstract: LY12 aluminum alloy was welded with vacuum electron beam welding, the effect of welding speed and electron beam current on the weld microstructure and mechanical properties of welding joints were studied, the results were shown that with the increasing of welding speed or decreasing of electron beam current, the grains in weld metal were refined, so the joint strength were increased. When the electron beam current was 18mA, the welding speed was 1000mm/min, the grains of weld metal were the finest, and the tensile strength was 373.2MPa. In addition, the micro-hardness of weld metal was much lower than base metal and heat affected zone, and the heat affected zone had certain softening phenomenon. With the increasing of welding speed or decreasing of electron beam current, the micro-hardness of weld metal was increased respectively.

Abstract: Boron doped ZnO (BZO) thin films were deposited on glass substrate by ultrasonic spray pyrolysis method using zinc acetylacetonate and boric acid. The structural, morphological, optical and electrical properties of BZO thin films under various doping level of boron and substrate temperature were investigated. The results show that zinc acetylacetonate is helpful to deposit BZO thin films at low temperature. The morphology of grains at low and high substrate temperature is circular and flake-like. The preferred orientation along (101) plane is obvious at 360 °C. The doping level and substrate temperature have remarkable influence on sheet resistance, but little impact on visible transmittance. The optimal sheet resistance of 173 Ω/sq and average visible transmittance of above 80% can be achieved at doping level of 5 at% and growth temperature of 340 °C.

Abstract: The Simufact material forming finite element software is used to simulate the cartridge backward power spinning process, the material strain and materials flow pattern of the cartridge case deformation zone of spinning process are analyzed. We obtained the conclusion that the materials radial pressure is much greater than the axial and tangential stress, and the radial material flow rate is largest, followed by tangential flow rate, axial flow rate is smallest in deformation zone. The results has certain guiding significance in preventing the produce expanding, necking, uplift and other defects, optimize spinning process.

Abstract: Development of new and efficient demulsifier and decalcifying agent of crude oil has important significance for improving the processing properties of heavy crude oil and increase the yield of light oil. High salt and water contents of crude oil after electric desalting is easy to cause the rapid expansion of volume of water after vaporization, the gas load of distillation tower increases, interfering the smooth operation of distillation tower, A slight impact will influence the quality of products separation, serious implication form the accident of punching Tower caused by the "bumping" of water; increase energy consumption and corrosion of equipment, influence twice processing quality of raw material. In addition, in processing high acid and high calcium crude oil, the presence of naphthenic acid calcium is easy to make the chaos of electrical desaltinger operation. Metal calcium may reduce the activity of catalyst of catalytic cracking and hydrocracking, increases petroleum coke ash in delayed coking, reduces the ductility of oil asphalt, aggravates the corrosion of refinery equipment, influences the safety of production. This requires to optimize the distillation technology of desalting equipment, to develop the evaluation and selection of demulsifier and decalcifying agent and reduce the moisture and salt content of desalted crude oil.

Abstract: In this report the gas chromatography column was fabricated base on micro electro mechanical system (MEMS) technology. It tries to find an equilibrium point which can fast detect CWA stimulants with efficient column separation. Under deep reactive-ion etching (DRIE) process, a 1m length, 90 um thickness and 300 um height which form 3:1high-aspect-ratio, MEMS-based silicon GC column was fabricated. The GC column was coated with 95%Methyl 5% Phenyl Polysilozane (DB-5) as the stationary phase. Dimethyl methyl phosphonate (DMMP), Triethyl phosphate (TEP) and Methy salicylate were used for CWA simulations. All of these three samples can be separated less than 90s with reasonable column efficiency.