Back to Search
Start Over
Surface strengthening and self-lubrication enhancement of CoCrNi medium-entropy alloy by powder-pack boronizing.
- Source :
-
Wear . Jul2022, Vol. 500, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
-
Abstract
- The CoCrNi medium-entropy alloy (MEA) exhibits an impressive ductility, but its low hardness (∼352 HV) and poor wear resistance limit its engineering applications. In this study, a significant increase of surface hardness and enhancement of self-lubrication were achieved for the CoCrNi MEA using powder-pack boronizing. Results indicate that dual reaction layers with a total thickness of about 50 μm were formed on the surface. These two strengthened layers are mainly consisted of silicide (Ni 2 Si) and borides (CoB, Cr 5 B 3). The hardness of the affected region reaches to 11–21 GPa dependence on the cross-sectional depth, being about 6 times higher than that of untreated MEA. In the deionized water condition, the friction and wear rate reductions of the boronizing treated specimen reach to about 25% and 63%, respectively. Energy Dispersive Spectrometer (EDS) and X-ray Photoelectron Spectroscopy (XPS) analysis on the wear scars showed that a silicon/boron-containing tribofilm was formed under the water environment, which reduces the friction coefficient and enhances the wear resistance. Our study demonstrates that powder-pack boronizing is a powerful way to enhance surface hardness and self-lubrication properties of CoCrNi MEA. • Double-strengthened layers were observed on the boronized CoCrNi alloy surface. • An obvious improvement of surface hardness was obtained. • The self-lubrication performance of boronized CoCrNi MEAs in the water is excellent. • The self-lubrication enhancement was due to the formation of silicon-boron based tribofilm. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00431648
- Volume :
- 500
- Database :
- Academic Search Index
- Journal :
- Wear
- Publication Type :
- Academic Journal
- Accession number :
- 157004781
- Full Text :
- https://doi.org/10.1016/j.wear.2022.204353