Tribological Properties and Seasonal Freezing Damage Evolution of Rotating Spherical Hinge Self-Lubricating Coating

Abstract

The spherical hinge is an important part of rotating bridge construction, but over a long period of time, spherical hinge self-lubricating coating is easily eroded by water vapor. In this paper, the tribological properties and seasonal freezing damage evolution characteristics of a variety of rotating spherical hinge self-lubricating coating materials were studied by means of friction coefficient measurement experiments, friction and wear experiments and shear rheological experiments based on a self-developed indoor spherical hinge rotational friction coefficient tester. The results show that the self-developed indoor spherical hinge rotational friction coefficient tester can effectively and truly represent the working state and tribological properties of self-lubricating coating in practical engineering. A seasonal freezing environment has obvious influence on the tribological properties of spherical hinge self-lubricating coating, which is an irreversible process of deterioration. With the increase in the freezing–thawing cycle, the friction coefficient and viscosity of self-lubricating coating materials increase gradually, and the thixotropy and elastic recovery become worse and worse. When the content of graphene is 0.1%, the performance is the best. At room temperature and in a freeze–thaw environment, the friction coefficient of graphene grease is lower than that of PTFE 0.007 and 0.008, respectively. The diameter of the grinding plate is less than 0.075 mm and 0.001 mm, respectively. The maximum bite load without card is higher than 8.1% and 11.5%. The area of the thixotropic ring is lower than 41% and 42%. Phase transition points were higher than 42% and 64%. The apparent viscosity was higher than 6.6% and 74%. Graphene greases show the greatest bearing capacity, thixotropy and structural strength in conventional and seasonal freezing conditions and exhibit excellent tribological properties.

The Geometric Configuration of Lubricant Recesses of the Polymer Sliding Layer of the Bearing

“…In addition to polymers, the composite is filled with a large set of different materials, elements, and fibers (particularly fiberglass). Since these materials are often used as antifriction coatings, it is very important to study their tribological properties [40,41,60]. In general, the behavior of materials is influenced not only by operating temperatures and loads but also by the environment, in particular by oxygen and humidity.…”

“…Every year, there is an active production development of new antifriction materials, which can be used in various spheres of human activity, including medicine [33][34][35][36], mechanical engineering [37][38][39][40][41], bridge-building activity [42,43], etc. They are applied in different fields for approximately the same type of tasks, namely as a protective and reinforcing coating [38], such as corrosion protection [33], the use of biocompatible polymers as certain grafts [34,35], mouth guards [36], etc.…”

“…Designs 2023, 7, x FOR PEER REVIEW 3 of 18 different fields for approximately the same type of tasks, namely as a protective and reinforcing coating [38], such as corrosion protection [33], the use of biocompatible polymers as certain grafts [34,35], mouth guards [36], etc. They are used to reduce the size of multifunctional parts and structures [37,39], to reduce friction in bridge bearings [19,41], and in ball or roller bearings [40]. Polymers are used as protective antifrictional layers in bridge bearings.…”