Study on the thickness of lubricating film of M50‐Ag self‐lubricating composites

Abstract

Dry tribological tests of M50 matrix composites containing 0, 2.5, 5.0, and 7.5 wt% Ag are undertaken at 0.2 m/second 15 N from 25°C to 450°C against Si3N4 ceramic balls. The results indicate that the tribological performance is strongly dependent on the content of solid lubricant Ag. M50 matrix composites containing 5.0 wt% Ag exhibits the great tribological performance with the low friction coefficients of 0.23 to 0.43 and less wear rates of 1.89 to 3.52 × 10−6 mm3 N−1 m−1 from 25°C to 450°C, which is attributed to the formation of thick lubricating film on the worn surface. Furthermore, the migration model of solid lubricant Ag in M50 matrix composites is established to predict the thickness of formed lubricating film.

Design and Characterization of Self-Lubricating Refractory High Entropy Alloy-Based Multilayered Films

“…(e) Hardness reduction ratio of Ag-containing materials reported in the literature as a function of Ag content. References of other Ag-based fcc/bcc bimetallic multilayers, − HEA-based bimetallic multilayers, ,, and Ag-containing self-lubricating films. − …”

“…Due to this special coherent strengthening at small scales, it is noticed that the peak hardness of NbMoWTa/Ag can reach a high value with only 14% reduction in H when compared with the monolithic NbMoWTa. As the addition of a lubricating phase will inevitably deteriorate the mechanical properties, the hardness reduction ratio is found to increase greatly with the Ag content in self-lubricating films, as shown in Figure e. − However, by virtue of the unique structural design, the NbMoWTa/Ag multilayer can overcome the tendency of a substantial decrease in hardness (outlined by black circles), although a large number of Ag has been added.…”