Search

Nitrile butadiene rubber (NBR) is a water-lubricated bearing material that demonstrates excellent vibrational absorption and impact resistance; however, rapid wear under abnormal conditions is still a serious problem. Graphene (Gra) and carbon nanotubes (CNTs) are two types of carbon nanomaterials with different dimensions and excellent mechanical and friction properties. In this work, Gra and CNTs were used to fill the NBR, and a multifunctional friction and wear testing machine was used to study their impacts on the friction between NBR and ZCuSn10Zn2 under water lubrication conditions. The results indicate that both Gra and CNTs can effectively reduce the adhesion and the friction coefficient of NBR during the friction process. The two-dimensional lamellar structure of Gra is more likely to precipitate from the NBR matrix to generate a surface lubrication film, which can effectively reduce the friction coefficient. Both Gra and CNTs can prevent crack initiation and propagation in NBR during the wear process, thereby effectively reducing the wear of NBR. Compared with the two-dimensional structure of Gra, the one-dimensional linear structure of carbon nanotubes can "trap" the NBR molecular chains more effectively during the friction process, thus reducing the initiation and propagation of wear cracks and further improving the wear performance of NBR. • Effect of different dimensions of carbon nanomaterials on friction behavior of NBR. • Effect mechanism of two-dimensional graphene and one-dimensional carbon nanotubes on friction behavior of NBR. • NBR wear mechanism enhanced by two-dimensional graphene and one-dimensional carbon nanotubes. [ABSTRACT FROM AUTHOR]

Unacceptable vibrations induced by the friction in the water-lubricated bearing-shaft system can seriously undermine the reliability and concealment performance of the ship. The mechanism of frictional vibration and the coupling process with torsional vibration are not yet entirely understood. In this study, a glass shaft is used to form a friction pair with a rubber block. To explore the frictional vibration mechanism and process of coupling with torsional vibration, a high-speed camera records the responses of the rubber, fixer and shaft simultaneously. The frictional vibration in stern shaft system is visually revealed by joint analysis of vibration, noise, friction, and images. Most importantly, the coupling process of frictional and torsional vibrations in the stern shaft system is intuitively displayed. • A transparent glass shaft was used to form a friction pair with a rubber test block. • With the help of a high-speed camera, the dynamic responses of the friction pair were recorded and analyzed. • The mechanism of frictional vibration was explained by joint analysis of vibration, noise, friction and image data. • The coupling process of frictional vibration and torsional vibration was explored visually. [ABSTRACT FROM AUTHOR]