This study aims to analyze the influence of macrosegregation on microstructure evolution, and of microstructure length scale on the corrosion resistance of a Zn-5.0wt.%Mg alloy casting. The analyzed samples were taken along the length of castings unidirectionally solidified in unsteady state conditions of heat extraction. Microstructure characterization, microhardness, linear polarization and electrochemical impedance spectroscopy (EIS) tests were performed. A unique type of microstructure was observed, characterized essentially by a morphology typified by idiomorphic MgZn2 crystals in a “complex eutectic mixture” [coexistence of stable (Zn+Mg2Zn11) and metastable (Zn+MgZn2) eutectics]. The correlation between thermal and microstructural parameters, permitted experimental growth laws, correlating the evolution of the lamellar eutectic spacing with the cooling rate to be established. Vickers microhardness and electrochemical corrosion tests showed that more refined microstructures associated with higher experimental cooling rates, are related to a better set of higher hardness and corrosion resistance.

Rotary jet spinning (RJS) and electrospinning are techniques to obtain fibrous scaffolds. RJS is a simple method, which fabricates three-dimensional fibers by exploiting a high-speed rotating nozzle, creating a polymer jet which stretches until solidification, and does not require high voltage. In opposite, electrospinning technique needs the presence of an external electric field to create fiber from the polymeric jet solution. This article investigates both processes using two different biocompatible polymers: Poly(L-lactic acid) (PLLA) and Poly(ε-caprolactone) (PCL). Samples were characterized by scanning electron microscopy, thermogravimetric analysis, differential scanning calorimeter, and Fourier-transform infrared spectroscopy. Morphological observations showed the efficiency of both techniques in obtaining nanofibers. Thermal analyses of data indicate immiscible property of different blends and the total solvent evaporation. In vitro cytocompatibility test showed that RJS and electrospinning samples exhibited good cytocompatibility. Based on these results, it may be concluded that the fibers obtained with both technologies are non-cytotoxicity and with good biocompatibility, and might be suitable for applications as scaffold for cell growth.