Impact and wear resistance of Al-7072 MMCs reinforced with SiC and Al2 O3

In the present investigation, an effort has made to evaluate the impact and wear resistance properties of Al-7072 metal matrix composites (MMC) reinforced with different weight percentage (0, 2, 4 and 6) of Al2 O3 & constant weight of 2% SiC particulates. Stir casting was used here for the production of Al-7072 MMC with different filler content. The impact strength of ASTM standard sample was assessed by charpy testing machine and wear properties were studied by using a dry pin-on-disc wear testing machine under dry condition with varying load, speed and time. By comparing the test results, it was observed that Al-7072 MMC containing 4% weight of Al2 O3 and 2% of SiC shows better impact and wear resistance properties. Consequently it could be a potential combination in designand manufacturing of automobile parts to get custom fitted properties

Microstructural characterization and indentation creep behavior of friction stir modified Al surface with iron powder

Iron powder mixed with methanol is spread on Al base plate and Friction Stir Processing (FSP) is carried out with a constant load of 8kN, imposing a feed rate of 0.3mm/s at different tool rotational speed. Processed materials are characterized for revealing the microstructural features. Further, indentation creep behavior was assessed both on the base metal and processed zone using tungsten carbide indentor at the temperature of 30 and 100°C. Creep curves are generated and steady state creep rate (SSCR) values at two different temperatures are determined which in turn enables to find out activation energy for creep process. The results of x-ray diffraction reveal the formation of solid solution and an intermetallic phase (Al13Fe4) accompanied with the process of grain refinement. The results of impression creep test indicate that SSCR for processed zone is more than that for base metal. Further, if tool rotation speed is increased, the activation energy for creep decreases