Mechanical properties of Al–Mg/Al2O3 nanocomposite powder produced by mechanical alloying

• The effect of Mg content on the microstructure of Al–xMg/Al2O3 was investigated.
• For the binary Al–Mg matrix, the predominant phase was an Al–Mg solid solution.
• With the increment of Mg to 15 wt.% the crystallite sizes diminish to 25.9 nm.
• The microhardness of the powder after 20 h milling reaches to 201 HV.

The effect of milling time on the microstructure and mechanical properties of Al and Al–10 wt.% Mg matrix nanocomposites reinforced with 10 wt.% Al2O3 during mechanical alloying was investigated. Steady-state situation was occurred in Al–10 Mg/10Al2O3 nanocomposite after 20 h, due to solution of Mg into Al matrix, while the situation was not observed in Al/10Al2O3 nanocomposite at the same time. For the binary Al–Mg matrix, after 20 h, the average crystallite size was 25 nm. Up to 20 h, the lattice strain increased to about 0.67% for Al–Mg matrix.By milling for 10 h the large increase in microhardness (190 HV) for Al–Mg matrix nanocomposite was caused by grain refinement and solid solution formation. From 10 to 20 h, slower rate of increasing in microhardness, and at 20 h micro hardness reach (201 HV).

X-ray diffraction patterns of Al–10Mg/10Al2O3 powder mixture for different milling timeFigure optionsDownload as PowerPoint slide