Structure and Properties of a Self-Lubricating Antifriction Composite Based on Regenerated Bearing-Steel Waste for Friction Units of Stencil-Printing Machines

This study investigates the influence of manufacturing technology on the structural, mechanical, and antifriction properties of a new self-lubricating composite based on ShKh15 bearing-steel grinding waste to which a CaF2 solid lubricant was added. The developed process involves regenerating grinding waste, mixing with CaF2 powder, pressing, and sintering. This process ensures the formation of a micro-heterogeneous structure consisting of a metallic matrix with uniformly distributed CaF2 particles. The strengthening phases and their distribution determine the composite’s tribological behavior under operating conditions of 100–200 rpm and 1.0 MPa in air. Compared to conventional cast bronze, the material exhibits superior wear resistance and a lower friction coefficient. During friction, self-renewing antifriction films form on the contact surfaces due to chemical interactions between metallic elements, oxygen, and the solid lubricant, providing a continuous self-lubricating effect. The results demonstrate that adjusting the initial alloyed waste powders and the CaF2 content makes it possible to control the structure and performance of the composite. This research highlights the potential of using industrial grinding waste to produce efficient antifriction materials while reducing environmental impact.