An investigation on SiC volume fraction and temperature on static and dynamic behavior of Mg-SiC nanocomposite fabricated by powder metallurgy

In this study, quasi-static compaction is employed to produce Mg-SiC nanocomposite samples. Different volume fractions of SiC nano reinforcement and micron-size magnesium (Mg) powder as the matrix are used to fabricate nanocomposite specimens. The powder mixture for each percent of SiC are mechanically milled. The mixed powder is then placed into a mold and is consolidated at different temperatures using Instron machine. MoS2 is utilized as a lubricant to decrease the friction between the fabricated specimen and the mold. It is found that with the increase of temperature the sintering requirements is met and higher quality samples are fabricated. The density, hardness, compressive strength in high and low strain rate of the compacted specimens are compared for different volume faction of SiC at 25, 250 and 450 oC. It was found that by increasing the content of nano reinforcement, the relative density of the compacted samples decreases, whereas, the micro-hardness and the strength of the samples enhance. Furthermore, higher densification temperatures lead to density increase and hardness reduction. Additionally, it is shown that the compressive strength at high strain rate compared to low strain rate is significantly improved by increasing the SiC nano reinforcement so that dynamic strength for the same level of SiC was 55% higher than the quasi-static strength.