Surface Property and Braking Reliability Analyses of YSZ Thermal Barrier-Coated Brake Disc of Kilometer-Deep Well Hoist

A significant amount of heat is generated during the braking process of a kilometer-deep well hoist, which causes a large temperature rise and then thermal deformation and cracks in the brake disc. Thus, improving the surface performance of the brake disc is necessary to ensure reliable braking under high-speed and heavy-load conditions. In this paper, thermal barrier coating technology is applied to a brake disc, and the friction and wear characteristics of a yttria-stabilized zirconia (YSZ) thermal barrier-coated brake disc is studied. A coupled thermomechanical model of the hoist disc brake is established, and a temperature field simulation analysis of uncoated and coated brake discs under emergency braking conditions is carried out. Then, a surrogate model of the maximum temperature of the brake disc surface with respect to the random parameters of the brake disc is constructed based on a Latin hypercube experimental design and the Kriging method. The reliability of the brake disc under emergency braking conditions is estimated based on saddlepoint approximation (SPA), and the feasibility of applying a YSZ thermal barrier coating to a hoist disc brake is verified.