TEM microanalysis of interfacial structures after dry sliding of cold sprayed Al-Al2O3

Particle-reinforced aluminum matrix composites (Al-MMCs) generally exhibit lower wear rates and more stable friction than their un-reinforced matrix materials. Cold spray is a popular consolidation route for Al-Al2O3, allowing for its application as a coating for corrosion and tribological protection. Previous work by the authors has found that 22 wt.% of angular Al2O3 particles (sample ANG22) leads to a significant decrease of the third body source flow and of the recirculation third body flow leading to a drastic decrease of the wear flow and thus of the wear rates. The greater friction stability in the case of sample ANG22 during dry sliding against sapphire compared to unreinforced pure Al cold sprayed coatings (sample CS0) is attributed to a specific thin third body to be characterized. Thus the goal of the present work is to compare the near-surface third body material for samples CS0 and ANG22 in terms of microstructure and chemistry, with transmission electron microscopy (TEM) methods, in relation to their hardness.