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The corrosion behavior of keyhole-free friction stir spot welded joints of dissimilar 6082 aluminum alloy and DP600 galvanized steel in 3.5% NaCl solution has been investigated by the immersion test and electrochemical analysis. The surface of the aluminum alloy produced exfoliation and pitting corrosion. The pitting occurred seriously on the interface of the 6082 aluminum alloy, but the steel had no corrosion. The corrosion galvanic couples were formed between elements of Si and Fe with a high electrode potential, and Mg and Al with a low electrode potential, around them. Mg and Al elements of Mg2Si and Si-containing solid-solution phase α (Al) preferentially became an anodic dissolution and formed exfoliation corrosion around the Si elements. Fe-rich phase θ (Al3Fe) as the cathode caused corrosion of Mg and formed pitting around Mg-rich phase β (Al3Mg2) as the anode. The sequence of the corrosion resistance of different areas of the joints (with decreasing corrosion resistance) was WNZ (Weld Nugget Zone) > TMAZ (Thermo-mechanically Affected Zone) > BM (Base Metal) > HAZ (Heat-affected Zone). The joints of keyhole-free FSSW (Fiction Stir Spot Welding) of dissimilar 6082 aluminum alloy and DP600 galvanized steel have better corrosion resistance than base metal in 3.5% NaCl solution. [ABSTRACT FROM AUTHOR]

An investigation was made on the electromagnetic shielding behaviour and other functional properties for manufactured multifunctional elastic warp-knitted fabrics. Bamboo charcoal polyester/Crisscross-section polyester (BC-PET/CSP) blended yarns were used as the back of the warp-knitted fabric while conductive composite yarns were used as the front. The variation in the far infrared emissivity and anion density of elastic-warp knitted fabrics produced with different proportions of BC-PET content were studied in detail. Moreover the electromagnetic shielding effectiveness (EMSE) of the fabrics with different elongation was measured in this study. The experimental results showed that increased elongation almost did not significantly affect the EM shielding behaviour of fabric K1 in the elongation range of 0 - 40%. Finally to increase the EMSE of the fabric, the lamination method was used in this study. EMSE measurement results showed that two layer K1 warpknitted fabrics with 90° interval displayed a better shielding effect against the EM wave compared to that with a 0° interval. [ABSTRACT FROM AUTHOR]