Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8025294 | Surface and Coatings Technology | 2016 | 9 Pages |
Abstract
We investigate the effect of low-temperature metal pretreatments in order to improve the adhesion of CNx coatings on steel substrates, which is crucial for tribological applications. The substrate pretreatments were conducted using five different metal targets: Ti, Zr, Al, Cr, and W, operated in high power impulse magnetron sputtering mode, known to produce significant ionization of the sputtered material flux. The CNx adhesion, as assessed by Rockwell C tests, did not improve upon Ti and Zr pretreatments. This is primarily ascribed to the fact that no interlayer was formed owing to severe re-sputtering due to high fluxes of doubly-ionized metal species in the plasma. A slight improvement in adhesion was observed in the case an Al pretreatment was carried out, while the best results were obtained using Cr and W. Here, 30-s-long pretreatments were sufficient to clean the steel surface and form a metallic interlayer between substrate and coating. Transmission electron microscopy in combination with energy dispersive X-ray spectroscopy revealed that Al, Cr, and W created intermixing zones at the interlayer/substrate and the interlayer/CNx interfaces. The steel surfaces, pretreated using Cr or W, showed the highest work of adhesion with WCradh = 1.77 J/m2 and WWadh = 1.66 J/m2, respectively.
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
Konstantinos D. Bakoglidis, Susann Schmidt, Grzegorz Greczynski, Lars Hultman,