Effect of Al2O3 particle size on compressive behavior of al composites

Abstract

Compressive behavior of 7xxx series Al metal matrix composite (MMC) powders with different ceramic contents and different particle size were investigated. As a starting powder of the experiments, ceramic contents of each starting powder were 5 and 10 wt.% and ceramic particle size of starting powder were 20 and 100 mu m, respectively. And 7xxx Al blended powder was used for comparison. The powders were uniaxially cold-compacted using cylindrical die with a compacting pressure 250 MPa and sintered at 620 degrees C in a dry N-2 atmosphere for 60 min with heating rate of 20 degrees C/min. In case of heat treatment condition, sintered parts were solution treated at 475 degrees C and aged at 175 degrees C. To reveal the effect of Al2O3 particle content and particle size on the mechanical properties of composites, compression test were conducted with constant strain rate of 1 x 10(-3)/s using sub-size cylindrical samples of 9 mm diameter. Compression test was performed 5 times and its average value was used. Then fractography analysis was conducted using scanning electron microscope.