Advanced Materials Research Vols. 734-737

Abstract: A new method for producing titanium and titanium alloys was studied at this paper. The experiment results indicate that Na₂TiO₃ could be synthesizing by heating at 450°C using NaOH and TiO₂ powders.Metallic titanium was observed in XRD pattern of the electrolytes after experiment by means of constant-current electrolytic Na₂TiO₃ in a CaCl₂-CaF₂ melt at 850°C.Thendepending on the electrolytical residua,titanium aluminium alloy could be obtained by calcining with Al powders.

Abstract: Aluminum-based metallic material as the frame or the skin material is widely used in vehicle industrial production. The electrostatic charge accumulate on the surface of the material,because of triboelectrifiction with space particles. And the electrostatic discharge would impact the vehicle or appliance around enormously. In order to study the triboelectrifiction, principle of space particle and space charge is analyzed and theoretical calculation formula is derivate. The fact is found that the charge of material is growth in negative index with time dependence, and get steady at the end. The saturation value and saturation time will be decrease when the charge factor of space charged particle increases. To make sure the conclusion is right, a part material of one aerial vehicle is taken into the test. From the experimental results of different material, angular velocity and contact area, the conclusion gotten above is proved by test data.

Abstract: The glass-ceramics was prepared by the whole crystallization process using the sediment from the Yellow River as the main materials. The sediment using from Huayuankou in Zhengzhou was melt at 1200°C for 2 hours to get the clarifying and homogeneous glass liquid. The modeled glass liquid was annealed and fired to get glass-ceramics. The glass-ceramics with natural texture and soft colour can supply better architectural effect and the microstructure was combined the crystal and the glass phase with the help of scanning electronic microscope (SEM).

Abstract: Based on the fractal contact theory, the model about the relation between normal contact stiffness and material properties as well as fractal parameters is established. Then by making use of the relation between fractal parameters and surface roughness, a new method for estimating the normal contact stiffness is put forward. The numerical results indicate that the contact stiffness increases as surface roughness decreases or adhesion rate increases. When the adhesion rate is constant, contact stiffness changes a little while R_a≥6.3μm, but the change is relatively bigger when R_a≤6.3μm. Considering both the cost of surface machining and the influence of contact stiffness on the whole system, the surface roughness is suggested to be R_a=6.3μm. The results provide theoretical supports for vibration isolation analysis with gaskets and the process of low-noise construction.

Abstract: This paper presented a new multiscale finite element method for mechanical analysis of irregular porous materials. Realization of the proposed approach requires synergy between a hierarchical geometric model and a mechanical model for local material properties. The geometric model can represent intermediate scales and facilitates continuous bi-directional transition between macro-and micro-scales, while the mechanical model preserves the effective material properties for each scale.

Abstract: In HCl solution, the Se (IV) was reduced to SeH₂ by NaBH₄, and absorbed by solution of ethanol-AgNO₃. The Ag⁺ was reduced to nanosilver, which led to the resonance Rayleigh scattering (RRS) peak at 366 nm increased. Under the selected conditions, the RRS intensity at 366 nm was linear to the concentration of Se (IV) in the range of 0.05-2.0 μg/mL, a detection limit of 0.02 μg/mL. The proposed method was applied to detect Se (IV) in water samples, with satisfactory results.

Abstract: This paper studied the performance of self-piercing riveting (SPR) of aluminum and copper alloy sheet. The SPR process of two copper alloy sheets was analyzed by experimental tests and finite elements stimulation, and good agreements between the simulations and test results of SPR process were obtained. Two different specimen geometries were adopted in experiment: a lap-shear type specimen and a T type specimen. The influence of combination of different materials on the static strength of SPR joints were studied through the tensile-shear and peeling experiments, and the strength of the SPR joints were evaluated by the force-displacement curves of two type specimens. The failure mechanisms corresponding to the static strength were also discussed. On the other hand, the engineering stress - strain curves of two materials have also been studied roughly. These results could provide designer engineers with some application messages of SPR.

Abstract: Chose high-chromium cast iron as the material to make the mud pump shell, the composition of high-chromium alloy has been optimized and five kinds of alloy ( A, B, C, D and E) are designed. Furthermore, using the heat treatment method of air-cooled quenching of 1040°C + 260°C tempering, the relationship among material hardness, the impact toughness and the heating temperature is analyzed after heat treatment. Finally, the abrasion performance of wear-resistant materials is tested. The test result shows that all kinds of wear-resistant materials display well anti-abrasion performance, where the material E has the best relative wear resistance and 19.3% higher than the imported pump casing material. The results provide a scientific standard for selecting the practical wear-resistant materials and locating the piece casting bivalve pump of Cr26 high-chromium cast iron.

Abstract: As a new chemical material, carbon fiber is widely used in national defense and civil industries due to the strong tensile strength of carbon and the flexibility and workability of fiber. Through collecting and sorting relevant data, this paper summarized and analyzed the application of carbon fiber in apparel industry, especially in the field of electrical heating clothing, meanwhile pointed out a few issues to be solved for carbon fiber heating clothing in terms of safety, buttery durability, construction and fabric etc.

Abstract: Mesoporous MCM-41 molecular sieve was synthesized hydrothermally and selected tetraethoxysilane as silica source. Solid superacid SO₄^2- / SnO₂ was supported on MCM-41 by dipping and roasting. The samples were characterized by XRD, TEM, and FT-IR. Solid superacid evenly dispersed on MCM-41 with a good pore structure. Their catalytic activities were evaluated in the isomerization of α-pinene. The results show that samples had a good conversion rate and selectivity.