A challenge in producing a sacrificial anode through conventional casting method is that the alloying elements in casting segregate during solidification, which further causes non-uniform anode corrosion reducing anode performance. In this paper, we investigated the performance of Al-5Zn-0.02In anode produced by conventional casting compared with by semi-solid casting technique. The performance of produced anodes were measured in terms of anode potential, current capacity, consumption rate and anode efficiency in 3.5% NaCl solution for 14 days. We found that the microstructure of the conventional cast anode had dendrites and coarse grains and the corrosion caused pitting corrosion. In contrast, the semi-solid cast anode had fine grains without any dendrites. The corrosion attacked mainly the grain boundaries and less on the matrix. Surprisingly, the conventional cast anode has about 10% higher efficiency than that of semi-solid cast anode.

Nanostructured porous silicon layer were successfully formed by an anodization method in viscous electrolyte containing glycerol and NH4F solution. P-type (100) silicon wafers were anodized with various anodizing times (1-8 h), NH4F concentrations (0.5-3 M) and applied voltages (10-30 V). The current density characteristic during anodizing and the morphology of porous silicon were measured using data acquisition loggers and field emission electron microscope (FE-SEM), respectively. The anodized surface produced high surface roughness and showed two types of porous structures consisting of macropores (macro-PSi) and mesopores (meso-PSi). The meso-Psi located in the macro-PSi structures. The size of macro-PSi increased with the increase of anodization time, the decrease of NH4F concentration and the decrease of applied voltage. The average diameter and depth of macro-PSi varied from 0.34 to 1.40 μm and 54 to 446 nm, respectively. For the meso-PSi, this method can produce an average diameter and thickness of mesopores in the range of 19-33 nm and 52-157 nm, respectively.