Tribological Effects of Nanofluids on Aluminum and Copper
Nanofluids are suspensions of solid metals, oxides, carbides or
nitrides nanoparticles, or of carbon nanotubes or nanofibers (typically up to
5%) in a continuous and saturated cooling fluid (as water, and ethylene glycol).
They are predicted to have higher thermal conductivity and heat transfer
coefficients than those of the base fluids, and they are promising as coolants
for critical-cooling systems [1]. However, many unknowns remain, particularly about
nanofluid wear and erosion of cooling system materials. The authors'
jet-impingement test rig proved appropriate to investigate early interactions
effects of nanofluid on typical cooling system materials, and roughness
measurements seems to be a suitable technique to detect early surface changes.
Comparative roughness measurements indicate that alumina nanofluids in water and
ethylene glycol can start surface changes on aluminum surfaces, but show no
effects on copper. Surface changes seem related to material removal through
abrasion.