Erosions- Corrosion Behavior of (Al-Y2O3) Composite Prepared by Powder Metallurgy

Aluminum has found many engineering applications due to its great formability, low density and high resistance to corrosion. Since aluminum is not very strong compared to other structural materials, it is usually strengthened by introducing second phase, reinforcing particles or fibers. The first aim of this work is to strengthen aluminum using powder technology. Yttria is selected as reinforcing particles. It is demonstrated that by adding yttria particles (3, 5,7 and 10wt% with particles size 5.54μm as reinforcing phase, aluminum can be strengthened and the microstructure of aluminum becomes finer with an increase in yttria content. The second aim of present work is to improve the erosion –corrosion behavior of aluminum metal matrix composite. An erosion-corrosion test for the prepared composite were carried out in slurry solution (1wt%SiO2 sand in 3.5wt% NaCl solution as the erodent) with impact angles (90°). Comparing with the base aluminum sample, Brinell hardness was increased by (83%) while erosion corrosion rate decreased by (91%) for the best sample which contained (10 wt.%) Y2O3 The improved properties of aluminum by the yttria addition may thus be attributed to residual yttrium in the Al matrix, and the resultant finer microstructure.