Effect of Secondary Structures on the Functional Properties of High-Speed Sintered Bearings for Printing Machines

Abstract

The paper examines the effect of operating parameters of new high-speed nickel-based composite bearing materials alloyed by molybdenum and tungsten and with additions of a solid lubricant, calcium fluoride CaF 2 , on the formation of dissipative secondary structures (friction films). It is shown that friction parameters substantially influence the nature of secondary structures responsible for antifriction properties. The wear mechanism of the materials is studied in different conditions of friction. Antiscoring films with smoothed microgeometry of contact surfaces are formed at 800−1000 rpm under a load of 6 MPa in air. In these friction conditions, the films ensure high wear resistance of the nickel-based bearing materials for rotary offset printing machines.

Analysis of the properties of antifriction composites based on aluminum alloy's grinding waste

“…Authors of [13][14][15]17] established that a multicomponent oxide film located on regenerated powders of the AM4.5Kd alloy consists of Al 2 O 3 and oxides of alloying elements. It protects wear-resistant material from oxidation at operation in air.…”

“…We can explain the selection of МоS 2 molybdenum disulfide solid lubricant and its amount by several rea-sons. First, we know that it is a solid-lubricant [17,18] chemically and thermally stable to 600 °C, which guarantees its unobstructed presence in a composite as in the manufacturing process, and in the process of exploitation of material. Second, molybdenum disulfide is an effective lubricant in the air under not difficult or medium-difficult conditions of operation of a part [7].…”

“…The first stage of compacting and consolidation was regeneration of output grinding waste of AM4.5Kd alloy by the developed technological modes [11,17]. First of all, there were cleaning of grinding waste from abrasive crumb by electrodynamic separation.…”

New Antifriction Composite Materials Based on Tool Steel Grinding Waste

“…Bearing materials based on iron are often used under working conditions in the air at temperatures of 500−600°C and high stresses (of up to 5 MPa), since other materials, primarily based on non-ferrous metals, show either low tribological properties or are not able to be suitably operated under such conditions. In addition, many cast materials significantly increase the cost of the friction unit and the mechanism as a whole [1], [4].…”

“…In some cases, cast materials have insufficient performance (high friction and wear coefficients) or are generally inoperable. Powder materials have a high cost due to the high price of raw materials (starting powders) [4], [5].…”