Papers by Keyword: Structural Application

Abstract: The potential of recycled wood flour (r-WF) addition to the thermoplastics polypropylene (PP) matrix for the composites in structural application is evaluated. The effects of different r-WF loading to the tensile and impact mechanical structural properties are analyzed. Two types of polypropylene resin which are the virgin and the recycled resin and recycled wood flour as reinforcement materials are utilized as raw materials in the composites fabrication. Various mechanical testing was conducted in accordance to ASTM standard, to study the behavior of the composites mechanical properties to the applied load. The best compounding formulation of enviro-recycled composite was found at 60wt% of PP matrix and 40wt% of the wood flour addition for both of virgin and recycle matrix. Overall experimental results showed that, the increasing of r-WF loading had significantly increased the mechanical properties of produced composite which is suitable to be applied in the application of structural engineering, through the advantage of mechanical properties performance in tensile and impact behavior. Conclusively, this finding is hoped to lead for contribution in the development of newly advanced material that is environmental friendly for the use of structural application.

Abstract: There is a fast moving trend towards using lightweight materials in automotive, aerospace, building and construction, body armour and protection, sports and leisure goods. The dynamic industrial development puts higher demands for lighter and yet stronger materials. Magnesium alloys potentially met the present demands for lighter and reliable construction. With comparable specific stiffness, higher specific strength and energy absorption magnesium alloys have the potential to replace steel and aluminum alloys. Magnesium alloys are very useful for applications where materials are subjected to variable or dynamic loads such as crash events in vehicles and planes, buildings and structures against projectiles penetration etc. To know the materials’ response to impacts and their resistance to blast and shock, it is necessary to understand their behaviour under static as well as dynamic conditions. In current study, magnesium alloys AZ91D and AM50 have been studied at dynamic loading conditions and compared with aluminum alloy AA6061-T6. With significant mass saving, higher specific properties and higher energy absorption under dynamic loadings, magnesium alloys are promising candidates to replace conventional materials not only aluminum but steel as well in structural applications.

Abstract: The continuous improvement of the applications of duplex stainless steels (DSS) is justified mainly by their excellent corrosion resistance in very aggressive environments and by their mechanical strength, often twice than that of conventional austenitic grades. Therefore more extensive applications have been suggested, like constructions, structural components, automotive applications, etc. However for such not advanced but quantitatively important applications the base cost of the alloy is one of the more constraining features. A way to obtain leaner alloys is to reduce the Ni content and to compensate with manganese and nitrogen additions. In the present paper the structural and mechanical properties of two low Ni duplex grades are analyzed in order to investigate the structural stability of the austenite against its possible transformation to martensite and the secondary phase’s precipitation. The detailed characterization has been performed with SEM-EDS on as received and heat treated (600-850 °C) alloys. A limited precipitation of chromium carbides and nitrides at the grain boundaries has been detected in both grades. The martensite formation has been revealed only in the 2101 grade. With regard to the impact toughness the behaviour of 2101 grade is quite similar to that of the common DSS, while in the 2304 the drastic drop of toughness is avoided. The corrosion behaviour of both grades in aggressive chloride environments is quite similar to that of austenitic AISI 304 grade.

Abstract: Galvanic corrosion is a particularly important form of corrosion for Mg alloys used in automobiles. Our research work focuses on corrosion protection using cost-effective Cr-free coatings. The top-tanking coatings are found to be effective in preventing general corrosion; some of these coatings are also good for reducing galvanic corrosion and stress corrosion. A practical approach for mitigating galvanic corrosion is to increase the electrolytic resistance between the coated steel and the Mg surfaces. This has been demonstrated in the case of a conversion coating plus a powder coat applied on the surface of a magnesium alloy and in the case of a thin Mylar isolation layer installed between the Mg and the steel surfaces.