Applied Mechanics and Materials Vols. 457-458

Abstract: In this paper, the physical and chemical properties of LaB₆ Ceramics are introduced, the influence of fabrication techniques on the microstructure and properties of LaB₆ Ceramics are discussed. The combustion synthesis process was considered as the proper method for fabrication of LaB₆ Ceramic powder with high purity. The results showed that the control additive has a great influence on the synthesis processand the nanoLaB₆ Ceramic powder with high purity can be produced made when the content of the control additive is 30%.

Abstract: A series of novel acidic ionic liquid: 1-ethyl-2-alkyl-benzimidazolium tetra-fluoroborate (alkyl= Et, Pr-n, Bu-n) were prepared by simple acid-based neutralization of 1-ethyl-2-alkyl-benzimidazole and tetrafluoroboric acid. The compounds were characterized by FTIR spectra, elemental analysis, ¹HNMR spectra and thermogravimetric analysis. These novel tetra-fluoroborate salts show good catalytic activity to esterification of benzyl alcohol and acetic acid. Furthermore, a crystal of ([H-ebBiBF₄) was prepared with the crystal structure and determined by X-ray diffraction analysis. The molecular is of lamellar structure as mainly π electron ring is stacked interleaving between two layers. The results of cation and anion arranged orderly in pair indicate that the coulombic attraction is more dominant. Simultaneously, the weak local hydrogen bonds C-H···F exist in the molecules.

Abstract: T-peel behavior of welded thermoplastic polyurethane elastomers (TPU) coated fabrics were investigated in this study, in consideration of the inhomogeneity of the strain distribution. The samples were welded by high frequency dielectric heating and then subjected to the T-peel test. The influence of the welding parameters on the welding strength was studied firstly. Then the T-peel process was analyzed using digital image correlation (DIC). The results showed the strain distribution along the direction of loading can be fitted by Gaussian function and the load grew exponentially as the increasing of the strain of the welded zone.

Abstract: A series of poly (N-isopropylacrylamide-co-glycyrrhetinic acid) (P(NIPAAm-co-GA)) microgels were prepared by dispersion copolymerization. The morphologies of the microgels were observed by field scanning electron microscopy (FE-SEM) and transmission electron microscope (TEM). The temperature sensitivity of microgels was examined by measuring the optical transmittance of the microgel aqueous solution. Cytotoxicity of the microgels was investigated by MTT assay. The results indicated that microgel particles had a regular spherical shape of about 500 nm with narrow size distributions. Moreover, P(NIPAAm-co-GA) microgels exhibited good temperature sensitivity and low toxicity. This novel microgel could be expected as good candidate for controlled growth factor release.Intorduction

Abstract: The sintering behavior and the resulting of cermet are influenced not only by the characteristics and impurities of the raw materials but also are found to be dependent on the thermal history during the fabrication process. Our work is concerned with the effect of sintering temperature on the mechanical properties of 17Ni/(10NiO-NiFe₂O₄) cermet. The nickel ferrite based cermet were prepared by hot-press sintering technology at 16MPa and sintered at temperatures ranging from 900 to 1200°C. The microstructure, phase compositions and mechanical properties were studied by SEM, XRD and three point bending strength tests respectively. It has been found that, the relative density, hardness and bending strength of NiFe₂O₄ based cermet have a great influence upon the sintering temperature, and an optimal sintering temperature, e.g. 1100°C is chosen through our experiments. The highest bending strength of 125.89Mpa could be obtained under the sintering temperature of 1100°C. Meanwhile, the thermal shock resistance increases as the sintering temperature increases.

Abstract: This paper describes a 3D-deform simulation of porthole die extrusion process for producing harmonica-shaped tubes used for a cooling system of automobiles. Designing the related structure of the porthole die and observing the simulation results, the study was designed to evaluate the welding effect when the length of bearing exit take different values.The mean pressure and exit velocity at the welding plane are analyzed at the same time. The welding effect is determined by the mean pressure at the welding plane .The behavior of metal flow in the container is analyzed in this paper. Through the above analysis, the best structure and size can be obtained in the process of deformation so as to obtain the better machanical properties.

Abstract: Milling of Al₂O₃ ceramic is affected by various factors. Combination of laser milling parameters was optimized based on orthogonal experiment in this study. The affect degree of the parameters on the milling depth was obtained by range analysis ,based on which process parameters were optimized and laser milling experiment was taken on circular cavity using optimized parameters. The results indicated that the sequence of the factors affecting on the milling depth was laser power,scanning speed, overlap amount,defocused quantity successively. By using optimized parameters,milling depth of 0.4mm was obtained for single layer experiment,and milling result was satisfactory. The roughness was increased because the molten on the specimen surface failed to be removed,thus the pressure of the assist huff gas should be increased to improve the surface quality.

Abstract: This test used countercurrent bubble contact flotation column in reverse flotation to improve the grade of magnetic concentrate. By the tests of operating conditions and reagent system experiment, when the ore grade of concentrate after magnetic separation is 42.15%, after one roughing ,we can obtain the grade is 65.82% and recovery rate is 62.79% of the concentrate.

Abstract: In this work, a porcelain enamel coating material for high temperature resistant on 1Cr18Ni9Ti stainless steel is designed and processed. The structure and properties of the material are analyzed by SEM, EDAX, XRD and FTIR. The results show that the surface of the enamel glaze and the enamel coating are smooth and bright, there is no obvious crystallization characteristics in porcelain enamel. There is litter oxidation and inter-diffusion in the interface between 1Cr18Ni9Ti stainless steel and porcelain enamel coating material after coating enamel.

Abstract: This paper via investigate the process of 9SiCr alloy steel in high efficiency deep grinding to find the rule between grinding wheel speed v_s depth of cut a_p and speed of table v_w with the grinding force and the surface quality. Intend to develop a suitable method of the grinding process of 9SiCr alloy steel in high efficiency deep grinding, to obtain high removal rate and good surface quality.