Authors: Qing Jun Chen, Lin Li Hu, Xian Liang Zhou, Xiao Zhen Hua, Ying Jun Yang
Abstract: The purpose of this study is to investigate the electrochemical properties of Fe44Cr16Mo16C18B6 amorphous alloy coating fabricated using high velocity oxygen fuel (HVOF) technology in 2.0M HCl and NaOH solution at room temperature(25°C). Based on the potentiodynamic polarization curves and Electrochemical Impedance Spectroscopy(EIS) testing results of coating in aqueous solutions of HCl and NaOH, the corrosion resistance of Fe44Cr16Mo16C18B6 amorphous alloy coating in HCl solution was superior to that in NaOH solution. The icorr was 1.487×10-5A·cm-2 in HClsolution and 1.107×10-4A·cm-2 in NaOH solution, while the Rt reach to 5.789×104Ω·cm2 and 9780Ω·cm2, respectively. On the other hand, these corrosion phenomenon could be better interpreted by R(Q(R(RQW)))(RL) and R(RL)(Q(R(CW))) equivalent circuit model, which were different from that of other Fe-based amorphous alloys in HCl and NaOH solution, respectively.
Authors: Qing Guo Hao, Jiu Ba Wen, Jun Guang He, Jing Ling Ma
Abstract: The open circuit potential, working potential and current efficiency of Al-5Zn-0.5Bi and Al-5Zn-0.5Bi-0.015Ga alloys in artificial seawater were tested by constant current method. The corrosion characteristics of the anode alloys in 3.5% NaCl solution were studied by polarization curves and electrochemical impedance spectra. The surface corrosion morphology and microstructures of the alloys were observed and investigated by metallographic microscopy, scanning electron microscopy and X-ray energy dispersive analysis. The results show that the open circuit potential shifts towards negative, working potential becomes stable and the current efficiency becomes high through the addition of gallium in the alloy. Gallium can be uniformly dissolved in aluminum alloy and effectively reduce the segregation of Bi. The cations can deposit back to the anode surface forming into the Ga-Al amalgam, which promotes its homogeneous dissolution and improve comprehensive electrochemical performance.
Authors: Zheng Xiao Liu, Jian Fei Xia, Zong Hua Wang, Yan Zhi Xia, Fei Fei Zhang, Lin Hua Xia
Abstract: A novel composite was firstly synthesized by compositing graphenes (G) and carbon nanotubes (CNTs) and then a new composite modified electrode (G/CNTs/GCE) was prepared by coating the resulting composite on the surface of the glassy carbon electrode (GCE). The composite modified electrode G/CNTs/GCE showed great electrochemical activities which were studied by sensitive determining the electrochemistry behaviors of uric acid (UA). It revealed when the concentration range of UA changed from 1×10-7 mol/L to 1×10-3 mol/L, the peak currents had linear relationship with the concentration of UA in the phosphate buffer solution (PBS) which the value of pH is 7.0. And the linear equation is ip (μA) = 21.55C+28.94 (C: mmol/L), with the related coefficient 0.9964.