Modes of wear of babbitt-based composite materials produced by hot pressing

Abstract

The effect of additives of Ti2NbAl intermetallic compound on the friction of B83 babbitt samples obtained by hot pressing was studied using optical, electron microscopy and EDS analysis. The structure, friction surface and wear products were studied. Tribological tests were carried out on a universal test system under conditions of dry sliding friction according to the scheme of axial loading: a steel bush against a disk of the material under study. The temperature values near the friction zone were recorded. The limits of application of the material depend on the mode and mechanism of wear occurring in the tribocontact. Changes in the mode and mechanism of wear were assessed by differences in the behavior of the friction coefficient, temperature, difference in the state of friction surfaces, wear intensity and wear products. The results obtained indicate the prospects of using the method of hot pressing of powder from the B83 alloy and discrete particles of the high-strength Ti2NbAl intermetallic phase to get composite materials with improved tribological properties compared to a babbitt alloy. The introduction of reinforcing high-modulus particles of intermetallic compounds changed the structure of the material and affected the friction processes in babbitt, pushing aside the onset of change in the mode of wear towards more severe friction conditions. A significant decrease in the wear intensity of babbitt-based composite materials compared to the original alloy makes it possible to predict an increase in the service life of tribo-units. The data obtained enable us to determine and recommend modes that improve the performance of tribo-nodes in the manufacture of both volumetric inserts and plain bearings made of B83 alloy and, moreover, to create new functionally organized layered compositions with enhanced tribotechnical properties with a base of structural steels and working surface layers not only using B83 babbitt, but also of composite materials based on B83 babbitt.