Surface degradation behavior of aluminium cenosphere composite foam developed by powder metallurgy route

The present study concerns understanding the effect of cenosphere content (5 vol% to 50 vol%.) on surface degradation behavior (by wear and corrosion) of aluminum cenosphere composite foam. Composite foam was developed by compaction of pre-mixed aluminum and cenosphere (varying from 5 vol % to 50 vol %) powders at a compaction pressure of 250 MPa, by two-step sintering. The density of the composite foam was found to decrease from 2.7 g/cm3 (as received aluminum) to 2.02-2.44 g/cm3 (aluminum cenosphere composite) and decreased with increase in cenosphere percentage. Detailed study of wear resistance against WC ball under fretting wear mode showed that the wear resistance of the foam increased with increase in cenosphere content up to 30 vol % following which it deceased. The mechanism of wear revealed that the mode of wear is due to the combined effect of adhesive and abrasive wear. A detailed study of corrosion resistance in a 3.56 wt % NaCl solution showed that the corrosion rate of foam increased up to 30 vol % of cenosphere following which it decreased. The EIS measurements and post corrosion microstructural observation confirmed that the interface between aluminum and cenosphere was the potential site for initiation of corrosion.

Automated summary

This study focuses on the effect of cenosphere content (5 vol% to 50 vol%.) on the surface degradation behavior (by wear and corrosion) of aluminum cenosphere composite foam. The composite foam was developed through compaction and two-step sintering. The density and wear resistance of the foam increased with the increase in cenosphere content up to 30 vol%, while the corrosion rate increased up to 30 vol% and then decreased.