Abstract
In the present work, Zn-Cr alloy coating have been deposited on a Ti + Nb interstitial free steel by an IBAD process. Zn was deposited by a resistance-heated evaporation source, while Cr was simultaneously evaporated with an electron beam gun. Low-energy Ar ion beam bombardment was used during the process to sputter-clean the surface prior to deposition and during deposition to obtain a dense coating. Different Zn:Cr evaporation ratios ranging from 30:30 were applied to produce several Zn-Cr alloy coatings until a final coating thickness of about 7 μm was obtained. The process was carried out at room temperature and XRD, which showed a change from the hexagonal Zn structure to a b.c.c. structure as the amount of Cr in the coating increased. Salt spray corrosion tests revealed that increasing the Cr content in the coatings improved significantly the corrosion resistance up to a maximum limit of about 20% wt., beyond which no substantial benefit could be observed. Mandrel bend tests showed a good adhesion of the coating to the substrate, and no delamination or cracks were observed. A dynamic microindentation test also showed the presence of chromium significantly improved the hardness of the Zn coating up to a factor of 5, with a similar effect on the elastic recovery of the indentation.
| Original language | English |
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| Pages (from-to) | 87-92 |
| Number of pages | 6 |
| Journal | Surface and Coatings Technology |
| Volume | 103-104 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - May 1998 |
| Event | Proceedings of the 1997 10th International Conference on Surface Modification of Metals by Ion Beams, SMMIB-97 - Galtinburg, TN, USA Duration: 21 Sept 1997 → 26 Sept 1997 |