Articles written in Bulletin of Materials Science
Volume 36 Issue 1 February 2013 pp 99-105
To improve the wear and corrosion resistance of AZ91D magnesium alloy, Zr-based coating made of Zr powder was fabricated on AZ91D magnesium alloy by laser cladding. The microstructure of the coating was characterized by XRD, SEM and TEM techniques. The wear resistance of the coating was evaluated under dry sliding wear test condition at room temperature. The corrosion resistance of the coating was tested in simulated body fluid. The results show that the coating mainly consists of Zr, zirconium oxides and Zr aluminides. The coating exhibits excellent wear resistance due to the high microhardness of the coating. The main wear mechanism of the coating and the AZ91D sample are different, the former is abrasive wear and the latter is adhesive wear. The coating compared to AZ91D magnesium alloy exhibits good corrosion resistance because of the good corrosion resistance of Zr, zirconium oxides and Zr aluminides in the coating.
Volume 36 Issue 4 August 2013 pp 505-511
Parallel-aligned zinc oxide (ZnO) nanofibrous films fabricated by using electrospinning technique were used in gas sensors for the detection of ethanol and formaldehyde. The morphologies and crystal structures of the films were characterized by field-emission scanning electron microscopy (FE–SEM) and X-ray diffraction (XRD), respectively. FE–SEM results showed that ZnO nanofibres had an approximate diameter of 100–300 nm and consisted of hexagonal wurtzite structure ZnO nanocrystals with a primary particle diameter of 20–50 nm. The results of resistance–temperature characteristics and responses to ethanol and formaldehyde indicated that the parallelaligned ZnO nanofibrous film had a low activation energy (0.246 eV), a low optimum operating temperature and a high response. The response and recovery had a high rate in the initial stage and a low rate in the later stage. The parallel-aligned ZnO nanofibrous film had excellent potential application for formaldehyde sensor.
Volume 42 | Issue 5
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