PSI - Issue 14

Vikas Verma et al. / Procedia Structural Integrity 14 (2019) 68–77 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

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Fig. 3. Wear testing machine

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Results and discussion

The density of the composites was measured by the Archimedes method and found that the highest density of 96% was obtained for Al alloy+5%Flyash+12%Al2O3 composite. The effect of stirring resulted in uniform distribution

of particles which increased densification. 3.1 Microstructural/compositional effects

The polished surfaces were subjected to microstructural characterization using a scanning electron microscope. SEM image in Figure 4(a) shows the dispersed, broken alumina oxide layer in aluminum matrix. It is observed that the oxide layer particles are irregular in shape distributed in the Al matrix. SEM image in Figure 4(b) is of Al Alloy+5%Fly ash+12%Al 2 O 3 prepared by reinforcement of Al 2 O 3 particles and flyash. It shows homogeneous grains and fine grain boundaries. Chunks of Al 2 O 3 particles and flyash are also visible in SEM image. Reinforced particles in molten matrix forms dendrite structure during casting.

Fig. 4. SEM images of (a) pure Al alloy (b) Al Alloy+5%Fly ash+12%Al 2 O 3