Sliding wear behavior of epoxy containing nano-Al2O3 particles with different pretreatments

The sliding wear performance of epoxy composites filled with nano-sized Al2O3 particles was studied in the present paper. To enhance the interfacial interaction between the fillers and the matrix polymer, the nanoparticles were pretreated by either silane coupling agent or graft polymerization. The experimental results indicated that the frictional coefficient and wear rate of epoxy can be reduced at rather low concentration of nano-Al2O3, and the pretreatments of the particles further gave play to this favorable effect. The lowest specific wear rate, 1.6×10−6 mm3/Nm, is observed for the composites with 0.24 vol.% nano-Al2O3 grafted by polyacrylamide, which is decreased by 97% as compared to the value of unfilled epoxy. Although the incorporation of nano-Al2O3 particles leads to increased flexural modulus and flexural strength of epoxy, the wear performance of the composites does not correlate with these static mechanical properties. In contrast, there is a positive correlation between wear resistance and impact strength (i.e. increase in impact strength correlates with a decrease in specific wear rate).