Corrosion resistance of Zr that has been added to an Al alloy (U1070) is higher than that of a commercial Al alloy (A1070). A decreasing number and size of Al3Fe intermetallic particles (IMPs) were observed by electron microprobe analysis and transmission electron microscopy. Based on the numerical corrosion simulation, it was confirmed that decreasing the number and size of IMPs was favorable for improving the corrosion resistance of the Al alloy due to the reduction of the galvanic effect. In addition, Al3Zr was found to be insignificant in promoting galvanic corrosion within the Al matrix. Thus, Zr is an advantageous alloying element for improving the corrosion resistance of the Al alloy.

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We demonstrated that the alignment of reduced graphene oxide (rGO) particles in dimethylformamide dispersions was electrically controlled. The field-induced alignment of the rGO particles imparted an optical anisotropy of both the birefringence and dichroism, simultaneously. The optical transmittance with crossed polarizers is determined by the combination of both birefringence and dichroism, and hence, it is somewhat difficult and inaccurate to calculate the degree of the ordering of rGO particles. On the other hand, by using parallel polarizers in the measurement, the birefringence effect could be eliminated, and we measured the order parameter of the rGO. Interestingly, the order parameter of rGO particles was high and comparable to that in GO dispersion. The saturated S order parameter at high electric fields decreased, as the rGO concentration increased. The field-induced rGO ordering will be useful for various applications such as flexible electronics and energy storage devices.