MICROSTRUCTURAL, MECHANICAL, WEAR AND CORROSION PROPERTIES OF Mg3Zn/TiB2-CNT NANOCOMPOSITES

Light magnesium nanocomposites, offering great weight savings, have a great potential to be utilized in aerospace and automotive industries. They have also been attracted much attention to be evaluated as biomaterial recently owing to their in vitro biodegradability and biocompatibility properties. In the present research, the Mg3Zn/TiB2-CNT nanocomposites were successfully manufactured using mechanical alloying, cold compaction at 600 MPa and finally sintering at 560 °C for 1 h. Their microstructural, mechanical, wear and corrosion properties were investigated extensively for comparison with the Mg3Zn alloy. It was found that the microhardness of the Mg3Zn nanocomposites increased directly with the hybrid reinforcement ratio. In parallel to the hardness, an addition of 15 vol % TiB2-CNT reinforcement to the Mg3Zn alloy allowed to the improvement of the compressive strength by of 46.3 % at a reasonable ductility level of ∼7.8 % compared to the Mg3Zn alloy. The crystallite size, decreasing with an augmentation in the reinforcement content steadily, was obtained to be smaller than 100 nm for the bulk Mg3Zn nanocomposites. Moreover, the wear loss of Mg3Zn alloy reduced by ∼45 % upon the incorporation of 15 % hybrid reinforcement due to the occurrence of a stable tribolayer between the working couple. An additional benefit of the incorporation of hybrid reinforcement into Mg3Zn alloy was also obtained in the progress of corrosion resistance significantly. The corrosion rate was recorded to be 1462.6 mpy for Mg3Zn but it decreased to 276 mpy upon the incorporation of 10 % hybrid reinforcement into the alloy.