A (CrFeNi)83(AlTi)17 high-entropy alloy matrix solid-lubricating composite with exceptional tribological properties over a wide temperature range
Publication Name
Journal of Materials Science and Technology
Abstract
High-entropy alloy matrix solid-lubricating composites (HSLCs) are promising anti-wear and friction-reduced materials to meet the demands of complicated engineering applications. Here we present a strategy to develop HSLCs by using the coupled high-entropy phases of (BCC + FCC + L21) with near-equal volume fraction as the matrix material, instead of using the usual single phase-dominated high-entropy phases, which can preserve the intrinsic strength and deformability of the matrix while activating adaptive wear protection during sliding. This enables a low coefficient of frictions of 0.23–0.31 and wear rates within the order of 10–6–10–5 mm3 N m–1 for the (CrFeNi)83(AlTi)17-Ag-BaF2/CaF2 HSLC between room-temperature and 800 °C, considerably outperforming the reported HSLCs and conventional alloy matrix solid-lubricating composites. At low and moderate temperatures, the synergistic Ag-BaF2/CaF2 lubricating films eliminate the surface stress concentration upon wear, thus suppressing three-body abrasion and surface roughening during the groove multiplication process. At elevated temperatures, the high-entropy composite tribo-layers provide the friction interface with strong and deformable stress shielding, which avoids the oxidative and adhesive wear triggered by the delamination of the tribo-layer. Developing similar coupled high-entropy matrix phases may open an avenue for further optimization of the tribological properties of the HSLCs.
Open Access Status
This publication is not available as open access
Volume
153
First Page
75
Last Page
91
Funding Number
20JR5RA571
Funding Sponsor
National Natural Science Foundation of China