Applied Mechanics and Materials Vol. 703

Abstract: Xylan preservative is harmless to humans and animals, contaminate the environment of new wood preservatives.This paper from bagasse, rice husk, corncob, xylan extracted from birch, testing the corrosion resistance of these four preservatives and CCA compared with the results show that: white rot fungus specimen weight loss rates were: Bagasse xylan: 2.41%, rice husk xylan: 2.65%, corn cob xylan: 2.53%, birch xylan: 2.33%, CCA rate of 4.08% weight loss.

Abstract: Silica-coated carbon nanotubes compounds were synthesized through coating silica nanoparticles on the surface of carbon nanotubes, by peptization and reflux method with tetraethoxy silicone as a main material. Silica coated carbon nanotubes-alumina composite ceramics were synthesized by adding the SiO₂/CNTs compounds to the alumina ceramic. The surface of composite ceramics were observed by scanning electron microscope (SEM), the coated nanotubes exhibit better dispersion in the alumina substrate over uncoated and play a role of bridging the alumina grains.

Abstract: The synthetic imidazoline-ammonium-salt corrosion inhibitor was compounded with sodium sulfite, isopropanol and potassium pyroantimonate respectively. Potassium pyroantimonate was selected as the best compound with good synergy. And the ratio of potassium pyroantimonate and the corrosion inhibitor was 3:50. Compared to the imidazoline corrosion inhibitor separately used, the inhibition efficiency was improved about 1.2% when the amount of the potassium pyroantimonate was 0.03%. Through researching the synergistic effect with polyaspartic acid, the green and high-efficient corrosion and scale inhibitor is got which is applicable to oilfield.

Abstract: This paper introduces the design of permanent magnet that can been used to small nuclear magnetic resonance (NMR) system, and its static magnetic field simulation analysis uses Ansoft's Maxwell software. According to the theory of magnetic circuit design and the performance requirements of magnetic field, An H-style permanent magnetic actuator has been designed, and it can generate uniform magnetic field larger than 0.4 T in the interested region of this actuator. The static magnetic field simulation analysis of this permanent magnetic actuator has done by Ansoft's Maxwell 3D software, and the experimental results show that the design of permanent magnet can meet the requirements.

Abstract: The tensile experiments were carried out under the condition of different pulse current on pure aluminum to analyze the effect of pulse current on the mechanical property such as tensile strength and elongation on material. The results show that pulse current could improve the mechanical properties and with pulse current the elongation of the aluminum increased to 19.5% and its tensile strength drops to some extent with the increase of electricity. At the same time, the dislocation structure features under different current density are also different. Without pulse current, dislocation is distributed as group unevenly. But when the current density J=8×10²A/cm², dislocation morphology changed into a mass of dislocation cells and moved to the grain boundary. Part of the cell walls formed grain boundary and then small angle subgrain formed. With the increase of current density, dislocation walls are arranged neatly and parallel to each other and at last single dislocation wall will be split into two or more parallel dislocation walls and form structure of striped band.

Abstract: HPLC was applied to measure the content of hemimelitene in industry product C₉ heavy aromatics. The optimal experiment condition was filtered mainly to find out the wave-length, mobile phase, the velocity and proportion of mobile phase, chromatographic column temperature which suited for hemimelitene, to improve the chromatographic separation degree of hemimelitene. From the experiment, we can make the conclusions: when wave-length is 297nm, mobile phase are methanol and water, which mobile velocity is 0.6ml/min and proportion is 50%:50%, column temperature is 25°C, the resolution and the spectrum are the best.

Abstract: Carbide end mills are quite expensive tools. Reduction of cost of such end mills while maintaining their key performance characteristics is an important and long-running task. One way for solution of this problem is to develop a composite end mill, which tail part is made of structural material and working part of carbide. Versions for positioning and connecting tail and working parts may differ, and this will influence the performance characteristics and, accordingly, the scope of application of a particular version of end mill. This work was supported by grants No2014 / 68 (Project 254) and No9.251.2014 / K (Project Code 251), Ministry of Education of the Russian Federation.

Abstract: In the paper, a region model considering grain shape, orientation and boundary is built based on Hall-Petch Equation. The constitute relationships of materials in grain region and grain-boundary region are deduced by introducing the scale parameter. The proposed model and constitutive relationships are verified by the experimental data. Using the region model, the micro-upsetting processes are simulated. The researches in the paper can be used to guide the other micro-forming processes which are more complex.

Abstract: The evolution of charge weld during multi-hole porthole die extrusion was studied by means of finite element simulation and Taguchi’s design. Moreover, based on S/N analysis, the optimal process parameters that can reduce the charge weld length was obtained, where the billet diameter is 100 mm, extrusion speed is 2.0 mm/s, tool temperature is 430 °C and billet temperature is 465 °C. The accuracy and effectiveness of such optimal process parameters were also verified. The purpose of the present study is to provide some information about the controlling of charge weld for extrusion engineers.

Abstract: It has been found that well-defined surface textures (such as micro-dimple arrays, micro groove arrays) can reduce friction, wear and improve heat transfer, fluid motion state effectively. To produce micro-dimple arrays on the metal surface with a high efficiency and low cost, this paper proposed a modified through-mask electrochemical micromachining method with flexible porous material filled in the interelectrode gap. The feasibility of the process and the most important process factor which affects the depth of the micro-dimple were investigated by orthogonal experiments. The results showed that micro-dimple arrays can be obtained efficiently using both direct current (DC) and pulsed current and the qualities of the micro-dimples generated by pulsed power were much better than those formed by DC. Electrolyte concentration was the most important factor that affected the depth of the micro-dimple in the selected process parameters.