The current research of nuclear control rod drive mechanism (CRDM) movable latch only makes a simple measurement of wear mass. The wear volume and difference in various claw surfaces are ignored and the degradation mechanism of each claw surface is not clear. In this paper, a detailed degradation analysis was carried out on each claw surface of movable latch combined with wear result and worn morphology. Results indicate that the boundary of carbide is preferred for corrosion because carbide presents a nobler Volta potential compared to the metal matrix or boundary region. Due to the oscillation of drive shaft between the claw surfaces of movable latch, the dominant wear mechanism on the upper surface of claw (USC) and lower surface of claw (LSC) is plastic deformation caused by impact wear. Mechanical impact wear will cause the fragmentation of carbides because of the high hardness and low ductility of carbides. Corrosion promotes the broken carbides to fall off from the metal matrix. The generated fine carbides (abrasive particles) cause extra abrasive wear on USC when the movable brings the drive shaft upward or downward. As a result, USC has a higher wear volume than LSC. This research proposes a method to evaluate the wear on the whole movable latches using a 3D full-size scanner.

Contact lenses have a special effect on the treatment of some eye diseases. The tribological behaviour of soft contact lenses considerably influences their clinical performance. Improper wearing of contact lenses can lead to mechanical damage of the contact interface, which can lead to pathological changes in the eyeball. In this study, the sliding friction of two kinds of typical contact lens materials (hilaficon-B and lotrafilcon-B) in three lubricants (distilled water, care solution, and eye drop) and tribological parameters are studied, using PMMA as a control. Hydrogels have high water content but the dehydration rate is high. Silicone hydrogels have low initial water content but low dehydration rates. The friction test in distilled water gives the highest coefficient of friction value. The care solution and eye drop significantly reduce the friction coefficient of the lens due to the formation of tribofilm.