Influence mechanism of grinding surface quality of 20CrMnTi steel on contact failure.

To reveal the influence mechanism of the grinding surface quality of 20CrMnTi steel components on the tribological characteristics and contact fatigue performance, accelerated tests for sliding friction wear and fatigue damage were carried out. Tribological characteristics and contact fatigue performance get worse with increasing surface roughness while getting better with increasing surface microhardness. Residual compressive stress is conducive to inhibiting the initiation and propagation of cracks and promoting contact fatigue performance.

A Novel Method for Early Fatigue Damage Diagnosis in 316L Stainless Steel Formed by Selective Laser Melting Technology.

Early fatigue damage is an important factor affecting the service safety of 316L stainless steel parts formed by selective laser melting (SLM) technology. Nonlinear ultrasonic testing for early fatigue damage in SLM 316L stainless steel specimens was carried out. A new method for evaluation of early fatigue damage based on nonlinear ultrasonic testing was proposed.

Phase Transition Effect on Ferroelectric Domain Surface Charge Dynamics in BaTiO Single Crystal.

The ferroelectric domain surface charge dynamics after a cubic-to-tetragonal phase transition on the BaTiO single crystal (001) surface was directly measured through scanning probe microscopy. The captured surface potential distribution shows significant changes: the domain structures formed rapidly, but the surface potential on polarized domain was unstable and reversed its sign after lengthy lapse; the high broad potential barrier burst at the corrugated domain wall and continued to dissipate thereafter. The generation of polarization charges and the migration of surface screening charges in the surrounding environment take the main responsibility in the experiment.