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7072Al is widely used as cladding layer for heat-transfer components. In this paper, the microstructure, mechanical properties and electrochemical properties of simulated-brazing 7072Al alloy with Zn addition were investigated. Transmission electron microscopy (TEM) observations revealed that, in the simulated-brazing state, Zn-addition could promote the precipitation in the 7072Al alloy. Tensile testing results indicated that, in comparison with 7072Al alloy, the mechanical properties were improved after Zn-addition. Electrochemical testing results revealed that the simulated-brazing alloy showed a negative shift of the corrosion potential with the addition of Zn element.

Effects of Zr addition on the microstructure, mechanical and electrochemical properties of Al–Mn–Si–Zn alloy were investigated. Transmission electron microscopy (TEM) observations reveal that, in as-annealled state, the precipitates in the Zr-containing alloy are finer and more dispersive than those in the Zr-free alloy. Whereas, in simulated brazing state, a weaker precipitation is found in the Zr-containing alloy. Tensile testing results indicate that, with Zr additon, comprehensive mechanical properties of the as-annealed alloys could be significantly improved but weakened for the simulated brazing alloy. Electrochemical testing results reveal that, with Zr addition, the corrosion resistance of the as-annealed alloy decreases. However, after the simulated brazing treatment, such a negative effect of Zr element on the corrosion behavior of the alloy could be negligible.

The effect of ion implantation on the electrical conducting behavior of neutral polyaniline (EB) has been studied and this is compared with the result of chemical doping (ES). The damage caused by ion implantation was analyzed with 4He+ Rutherfold backscattering spectroscopy. The experimental results indicate that the value of the resistivity in the carbon-rich layer of EB resulted from the bombardment of 150 keV Ar+ or F+ ions is the same as that of ES, which drops drastically from the value for EB by about 12 orders of magnitude. Within the temperature range of 130–310 K, the electrical conductivity of bombarded layers can be interpreted by Mott's VRH model. However, the transport process in ES may be limited by interchain hopping and the conductivity behaves as a thermally activated temperature characteristic. However, conductivity in the H+ implanted layer of EB with injection energy of 15 and 25 keV cannot be detected under our experimental conditions.