Issue 71

P. Doubek et alii, Fracture and Structural Integrity, 71 (2025) 67-79; DOI: 10.3221/IGF-ESIS.71.06

Material (specimen number)

Dimensions [mm]

CuAl/S960 (B9/17)

Hard chrome/S960 (T34)

Cobalt alloy (ST9/14)

Stainless steel/S960 (N9/17)

Height W ROI Width B ROI Depth H ROI

28.00 5.00 1.90 1.77 0.61

28.00 5.00 1.70 0.76

28.00 5.00 1.40 0.82 0.12

28.00 5.00 1.18 0.98

Thickness of the layer t Maximum length of damage

0.58 (0.27) 0.27 Table 3: Parameters of the monitored area of interest ROI and a maximum detected length of fault in the Y axis.

Material (specimen number)

Interval of length [mm]

Hard chrome/S960 (T34)

Stainless steel/S960 (N9/17)

CuAl/S960 (B9/17)

Cobalt alloy (ST9/14)

(0.02, 0.08> (0.08, 0.14> (0.14, 0.20> (0.20, 0.26> (0.26, 0.32> (0.32, 0.38> (0.38, 0.44> (0.44, 0.50> (0.50, 0.56> (0.56, 0.62>

11

0

0

122 110

9 0 0 0 1 1 1 3 1

41 25

22

2 0 0 0 0 0 0 0

14

3 1 1 2 0 0 0

7 1 0 0 0 0

0 Table 4: Interval distribution of frequencies of the detected defects according to a length in Y axis.

Aluminium bronze/S960 (B9/17) and Stainless steel/S960 (N9/17): Both samples evince very distinct and sharply restricted damage. The sample B9/17 has approximately twice the thickness of the layer and approximately twice times the maximum length of the defects presented than the sample N9/17 where fewer defects (about ten times) were detected, however smaller ones. The samples have a comparable porosity of the monitored areas of the deposit – 0.3% for B9/17 and 0.26% for N9/17. It is clear to see that in the sample B9/17, the damage appears almost exclusively to a depth of 0.6 mm and is often connected with the surface. On the contrary, the sample N9/17 has very little surface damage, but a large number of the defects can be found both between the individual layers of the coating and also at the border between the coating and the substrate, see Figs. 9 and 10.

12

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

1100%

10

900%

8

6

4

300%

2

Frequency of detected defects

100% 100% 100% 100%

0% 0% 0%

0

(0.08, 0.14>

(0.32, 0.38>

(0.44, 0.50>

(0.14, 0.20>

(0.26, 0.32>

(0.02, 0.08>

(0.50, 0.56>

(0.38, 0.44>

(0.56, 0.62>

(0.20, 0.26>

Interval of maximum length [mm]

Figure 5: Distribution of frequency of defects detected in sample B9/17.

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