Advanced Materials Research Vols. 295-297

Abstract: Three Dimensional Molded Interconnect Devices (3D-MID) has enormous potential for rationalization in both manufacturing process and the freedom to design of mechatronic products. Two shot molding is one of the most important and commonly used methods among the various MID manufacturing processes. Currently, there is a lack of effective design and simulation tools that can be used for MID with two shot molding. In this paper, an integrated product model using feature technology, some MID-specific design functions, and one special interface based on the API of Moldflow Plastics Insight (MPI) and the COM-Technology are presented. These developed product model, functions and interface increase the efficiency of the MID design process, and the design and simulation integrated environment also towards the rational and optimal design of MID products with two shot molding.

Abstract: The metal forming software Simufact is used to simulate tube spinning process. Different process parametes are received as result of simulation analysis, such as the maximum stress, maximum temperature, the amount of uplift and aperture expansion, and the method has been proposed to eliminate the defects.

Abstract: The float glass was polished by acid solution (HF/H₂SO₄) under ultrasonic wave. The surface morphologies before and after acid etching were observed by metallographic microscope. The thickness of acid etching was measured by thickness tester, and the strength before and after acid etching was investigated via material surface and interface performance tester. The experimental conditions, such as the amount of HF and H₂SO₄, the temperature of acid etching and the time of acid etching were optimized under ultrasonic wave ( f =40 KHz, P=125 W) by orthogonal design test. The suitable conditions were 10% for HF, 15 min for acid etching time, 30% for H₂SO₄ and 25 °C for acid etching temperature, and thus the strength of float glass increased from 89.68 Mpa to 302.25 Mpa. The optimum thickness for acid etching was about 40 μm. The microscopic pictures showed that the surface defects of the glass surface such as scratch and pit weakened obviously or disappeared.

Abstract: The Co-based alloy coatings were successfully fabricated on H13 steel by Nd:YAG and CO₂ laser. The microstructure and properties of the laser cladded coatings were compared and analyzed by SEM, EDS, XRD and microhardness tester. The results show that the excellent metallurgical bonding has formed at the interface between substrate and laser cladded coatings. Cellular crystal at the bonding zone, cellular dendrite at the central zone and reticular equiaxed crystal near top surface were observed in Nd:YAG laser cladded coating, while the typically hypoeutectic character was found in CO₂ laser cladded coating. Phase constituents of both coatings are mainly composed of Cr₂₃C₆, Co₃Mo₂Si, MoC, FeCr and γ-Co. The microhardness of H13 steel is greatly improved by laser cladding, however the microhardness of the CO₂ laser cladded coating is even higher than the Nd:YAG laser cladded coating.

Abstract: The morphology of inhibition layer and adhesion of Zn coating about a 600MPa grade high Al dual phase steel were studied by grow discharge spectrometry (GDS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the inhibition layer is mainly composed of Fe₂Al_5-xZn_x particles with a size of 0.5~1μm, and the adhesion is directly related to the density of the inhibition layer, the denser the inhibition layer, the better the adhesion. It is found: for the samples with good adhesion that besides the Fe₂Al_5-xZnx particles, there are also some small spherical Al-Mn oxides particles in sizes from 30 to 100nm uniformly distributed in the inhibition layer; for the samples with bad adhesion, the steel substrate is not fully covered by Fe₂Al_5-xZn_x particles and large amount manganese oxides are detected at the non-covered positions.

Abstract: Amphiphobic vaterite with a size of about 50 nm, was prepared via crystallization of CaCO₃ with perfluorooctane surfapropyl betaine（DF-921）in methanol by mimicking the process of biomineralization. The products were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and contact angle analysis. The results indicate that the CaCO₃ powder samples had both hydrophobic and oleophobic properties. The DF-921 used in this research not only controlled the crystal type of the CaCO₃ particles but also changed the surface properties of the final products.

Abstract: A layer of sword-like super-hydrophobic film was fabricated on wood surface through an alkaline hydrothermal method. The super-hydrophobic property of the wood surface was measured by contact angle measurements (CA). The microstructure and chemical composition of the super-hydrophobic film was analyzed by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). Analytical characterization revealed that the micro-scale roughness sword-like particles uniformly erect on the wood surface and create the rough surface. Also, a monolayer of stearic acid was adsorbed on the rough surface which contributes to reduce the surface energy. With the combination of roughness and low surface energy of wood surface, the wood has turned its wetting property from hydrophilic into super-hydrophobic with a water contact angle 151^o, and the sliding angle is about 5^o.

Abstract: A ZrO₂-Y₂O₃-containing composite ceramic coating was firstly in situ prepared on AZ91D magnesium alloy by plasma electrolytic oxidation (PEO) technique in an alkaline silicate-containing electrolyte. The morphology, chemical composition and corrosion resistance of the PEO coating were investigated by environmental scanning electron microscopy (ESEM), X-ray diffractometer (XRD), energy dispersive X-ray (EDX) spectrometer, dropping corrosion and electrochemical corrosion test. The results showed that the ceramic coating consisted of two distinct structural layers: an outer loose layer and an inner dense layer; it was composed of t-ZrO₂, Y₂O₃, SiO₂ and some magnesium compounds, such as MgO, MgF₂ and Mg₂SiO₄. In addition, the ceramic coating also showed excellent dropping and electrochemical corrosion resistance, which was mainly attributed to its special phase composition and microstructure.

Abstract: Under certain conditions, a test about the crackle-simulated coating technology of rice-straw board after sanding its surface, which aims to determinate several indexes include the glossiness of the coating surface, the hardness and adhesion of the film, the ability to resist of denaturing, and the feel of the surface, etc. The result shows that: the technology of rice-straw board crackle-simulated coating is available to the medium density fiberboard furniture. Though the indexes of the hardness and adhesion of the film are slightly low, they are all up to the standard of the nation and the enterprise. Moreover, we have also analyzed the decorating effect of the crackle-simulated coating of the surface, the economic cost, the environmental friendliness and other elements, in order to provide a reference frame to the special coating which is conducted on the furniture surfaces.

Abstract: The formability of the magnesium alloy sheets is poor at room temperature even though the magnesium alloy sheets are attractive because of their excellent characteristics. Hydro-forming technology, especially the pulsating hydro-forming, may be a way to improve the formability. Finite element simulations have been conducted to investigate the formability of AZ31B magnesium alloy sheet in hydro-bugling by pulsating hydraulic pressure. The influence of linear pressure, pulsating pressure and pulsating frequency on the maximum bulging height and minimum wall thickness of the formed parts have been analyzed. The research results show that the formability of AZ31B magnesium alloy sheet can be improved dramatically by pulsating hydro-forming. And enough bugling height can be obtained by lesser forming hydraulic pressure. The AZ31B sheet has an excellent performance in formability when the pulsating frequency is properly selected.