Researchers have discovered a swirling, fluidlike behavior
in a solid piece of metal sliding over another, providing new insights into the
mechanisms of wear and generation of machined surfaces that could help improve
the durability of metal parts.
Studies using a microscope and high-speed camera revealed
the formation of bumps, folds, vortexlike features and cracks on the metal
surface. The findings were surprising because the experiment was conducted at
room temperature and the sliding conditions did not generate enough heat to
soften the metal.