3.3 Tribological properties of Cr-B-C-N coatings in artificial seawater
Fig.10 shows the friction behaviors and the mean-steady friction coefficients of Cr-B-C-N coatings sliding against SiC balls in artificial seawater. As seen in Fig.10a, it is clear that the CrCN coatings showed higher friction coefficient than other coatings during the tribo-test in artificial seawater. The initial friction coefficient of CrCN coatings was 0.17, while that of CrBCN coatings ranged between 0.14 and 0.15. For the CrCN/SiC tribopairs, the corresponding friction coefficient increased continuously from 0.17 to 0.23 within 281 m, and then fluctuated around 0.22 with further sliding to 500 m. As for CrBCN-1 coatings, the friction coefficient decreased from 0.15 to 0.13 at the first 108 m, and then increased slightly to 0.16 during …show more content…
As seen in Figs.12 and 13, the CrCN coatings showed a wide and deep wear track, and grooves could be observed on the wear track. For the CrBCN-1 coatings, the width of wear track decreased sharply to the minimum value of 54.4 μm, and the depth was also dramatically decreased. As for the CrBCN-2 coatings, the wear track width increased to 184.6 μm, and the corresponding depth also increased dramatically due to the slight delamination which could be observed on the edge of wear track, thus, the specific wear rate of CrBCN-2 coatings was higher. For the CrBCN-3 coatings, the wear track became narrower and shallower, and no obvious grooves could be observed. For the CrBCN-4 coatings, the wear track was coarse and wide, and many obvious grooves could be observed. It is necessary to point out that the depth of wear track for all coatings was less than the corresponding coating thickness, in other words, all Cr-B-C-N coatings did not fail of work and showed relatively good tribological properties during sliding against SiC ball in
Fig.10 shows the friction behaviors and the mean-steady friction coefficients of Cr-B-C-N coatings sliding against SiC balls in artificial seawater. As seen in Fig.10a, it is clear that the CrCN coatings showed higher friction coefficient than other coatings during the tribo-test in artificial seawater. The initial friction coefficient of CrCN coatings was 0.17, while that of CrBCN coatings ranged between 0.14 and 0.15. For the CrCN/SiC tribopairs, the corresponding friction coefficient increased continuously from 0.17 to 0.23 within 281 m, and then fluctuated around 0.22 with further sliding to 500 m. As for CrBCN-1 coatings, the friction coefficient decreased from 0.15 to 0.13 at the first 108 m, and then increased slightly to 0.16 during …show more content…
As seen in Figs.12 and 13, the CrCN coatings showed a wide and deep wear track, and grooves could be observed on the wear track. For the CrBCN-1 coatings, the width of wear track decreased sharply to the minimum value of 54.4 μm, and the depth was also dramatically decreased. As for the CrBCN-2 coatings, the wear track width increased to 184.6 μm, and the corresponding depth also increased dramatically due to the slight delamination which could be observed on the edge of wear track, thus, the specific wear rate of CrBCN-2 coatings was higher. For the CrBCN-3 coatings, the wear track became narrower and shallower, and no obvious grooves could be observed. For the CrBCN-4 coatings, the wear track was coarse and wide, and many obvious grooves could be observed. It is necessary to point out that the depth of wear track for all coatings was less than the corresponding coating thickness, in other words, all Cr-B-C-N coatings did not fail of work and showed relatively good tribological properties during sliding against SiC ball in