Microstructure and Near-Surface Tribological Property Correlations in Al-Cu Alloy Reinforced with Al2O3 Nanoparticles

Strength and wear properties of metal matrix composites are important because of their numerous applications in automotive and aerospace industries. In the present study, Al-Cu alloy-based nanocomposites reinforced with different volume percentages of Al 2 O 3 particles were developed by reactive stir mixing of nanocrystalline CuO powder in molten Al. X-ray diffraction (XRD) patterns of the resulting nanocomposites revealed the presence of Al 2 O 3 reinforcements and CuAl 2 intermetallic particles. Microstructural characteristics of the samples were investigated and analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM analysis revealed the presence of geometrically necessary dislocations and microcracks inside the sample. Average dislocation density was determined by the modified Warren–Averbach method from XRD patterns. The near-surface wear behavior of the composites was studied by nanoscratch tests. The results were correlated with the microstructural features and dislocation density.