Figure 3
From: Understanding Tribofilm Formation Mechanisms in Ionic Liquid Lubrication

Wear debris collected from the steel–steel contact lubricated by the base oil with 1% IL. (a) BF-STEM images of the aggregations of wear debris particles, with a magnified view showing a cluster of nanoparticles. (b) EDS elemental maps of the three types of particles: (b-1) acicular, (b-2) flaky, and (b-3) fine spherical.