Applied Mechanics and Materials Vols. 365-366

Abstract: Geotextiles have been commonly used globally, making the control of material selection to influence geotextiles properties an important research topic. This study aims to explore the effects of the ratio of high-strength polyethylene terephthalate (HPET) fiber to Kevlar fiber on hybrid geotextiles. At the first stage, HPET and polyethylene terephthalate (PET) fiber are combined to make HPET/PET hybrid geotextile and then tested for porosity and water permeability, determining the optimum HPET/PET ratio. At the second stage, with a content of 60 % PET fibers, HPET fibers and Kevlar fibers are mixed with various ratios to form Kevlar/HPET/PET hybrid geotextiles. The experimental results show that with an increase in the content of HPET fibers, the porosity and water permeability of the Kevlar/HPET/PET hybrid geotextile decrease.

Abstract: This study aims to fabricate strong mechanical properties and electrical conduction woven fabric, which provides flexible and strength for application. Polyethylene Terephthalate fiber (PET fiber) having fine mechanical properties are widely used in industry, as well as metal fiber are often used on electromagnetic shielding and static electricity protection. This study took both advantages of PET fiber and metal fiber for water sensitive functional textile. The result showed that warp yarns has a tensile strength of 1363.3N/mm and weft yarns has a tensile strength of 1483.3N/mm. In addition, both textiles with 20 wt% water absorption can be electrical conduction. Various metal yarns have different electrical resistivity and conductivity with various water absorption percentage.

Abstract: Due to the prominent mechanical and physical properties, CFRPs have a broad application prospects in many domains. Aiming to the problems faced by available machining processes of CFRPs, this work proposed an integrated manufacturing process of CFRP parts by combining RFI process with cutting process, which replaced machining processes of the difficult-to-machine CFRPs with cutting of the flexible carbon fiber fabrics infiltrated by melted resin matrix. And it carried out molding, cutting and curing in a press stroke by a multi-functional die whose structure is given in this paper. Furthermore, by comparing the cross-section quality of CFRP parts obtained from the proposed integrated manufacturing process with that of drilling, mechanical machining and laser cutting, the integrated manufacturing process is verified to be feasible, cost-effective and capable of avoiding subsequent machining processes of difficult-to-machine CFRPs.

Abstract: This paper focuses on the influence of temperature and holding time on synthesizing MgAlON-SiAlON powders applying CRN method. The results were analyzed by chemical and XRD analysis technology. The experimental results revealed that β-SiAlON, as an intermediate phase, appeared in the synthesized products at 1200°C. With the increase of synthesis temperature, β-SiAlON was translated into Mg-SiAlON polytypoid (Mg_1.25Si_1.25Al_2.5O₃N₃) and reached the maximum at 1450°C. Increasing synthesis temperature was beneficial to generate MgAlON, and the optimal condition of temperature for powders synthesis was 1500°C. β-SiAlON disappeared with the increase of holding time. MgAlON and Mg-SiAlON polytypoid became the main crystalline phases with a holding time of 4h. Whats more, the phase compositions had no evident change with longer holding time. Flaky MgAlON grains and elongated Mg-SiAlON grains were observed in synthesized powders.

Abstract: Electrophoretic deposition is proposed to fabricate super-hydrophobic film on copper surface with reduced graphene sheets (RGSs). The resulted film was characterized with contact angle meter, scanning electron microscopy and so on. It is found that the film presents super-hydrophobic property with water contact angle of 150.4°. Air can be trapped in the island-like structure and intensify the wettability of film. Electrochemical measurements prove that super-hydrophobic film can inhibit corrosion process of underlying copper by inducing both anodic and cathodic current density. This method for super-hydrophobic film fabrication is facial and time-saving, and it will expand the application of RGSs in mechanical engineering.

Abstract: ETFE is the abbreviation of Ethylen Tetra Fluoro Etylene, a sort of colorless and transparent granules. The advantage ETFE film has daylight transmission and chemical resistance, the aging resistance and lightweight. The thickness of ETFE film is used to from 50μm to 300μm and tensile strength of ETFE film changes from 40MPa to 60MPa and the tensile strain at break can get to about 300-400%. In this paper, ETFE film carried out the tensile proprieties, such as the tensile strain at break, the tensile strength are examined.

Abstract: Ceramic coating was fabricated on AZ91 biomedical magnesium alloy by plasma electrolytic oxidation. The coating was then subjected to surface laser treating, and the influence of laser treating on the morphologies and corrosion resistance of the coating were investigated. The results showed that PEO coating without laser treating showed coarse and porous surface and the pores on coating surface were big. When subjected to laser treating, the pores on coating surface became little and few. The corrosion tests in SBF indicated that corrosion resistance of PEO coating on magnesium alloy sample could improve the corrosion resistance of the substrate, and surface laser treating could further increase the corrosion resistance.

Abstract: Al₂O₃ ceramic coating was fabricated on AZ91 biomedical magnesium alloy by plasma electrolytic oxidation. The microstructure of the coatings was characterized. The corrosion behavior of the coated magnesium alloy in simulated body fluids (SBF) was evaluated. The results showed that the as prepared coating was composed of crystal Al₂O₃, including much α-Al₂O₃ and some γ-Al₂O₃. The Al₂O_3. coating showed porous surface and the biggest diameters of the holes were about 6-7 um, and the smallest were about 1 um. The corrosion tests in SBF indicated that corrosion resistance of Al₂O₃ coated sample was significantly improved compared to the uncoated sample.

Abstract: This research used 20 kilograms crucible furnace to be experiment furnace. The furnace used NGV. to be fuel for aluminum melting while melting process melting time, melting temperature, pouring time and fuel consumption were recorded. The fuel consumption comparison between NGV. With LPG are one kilogram of aluminum used 0.35 kilogram of NGV or 3.92 Thai bath/kilogram (NGV .price 11 bath/kilogram) and one kilogram of aluminum used 0.25 kilogram of LPG or 4.53 Thai bath/kilograms (LPG.price 17.93Thai baht/kilogram)

Abstract: Achieving the monodispersion of Multi-walled carbon nanotubes (MWCNTs) is a challenging work for CNTs application. Centrifugation as a standard procedure was employed to remove remaining large bundles and leaving primarily individual nanotubes and small bundles in the supernatant. The optimum centrifugation time and force were 30min and 12×10³g, respectively , which were determined by UV-vis absorbance, transmission electron microscopy (TEM), Zeta potential and the residual MWCNTs concentration after centrifugation. Through centrifugation treatments, the uniform and stable MWCNTs monodispersion can be obtained and the Zeta potential was as high as-53.8mv after one month. The film formed from optimized MWCNTs monodispersed solution is smooth and flexible.