Figure 1.
Schematic of the set-up for a-C:H deposition by direct current discharge.
Figure 1.
Schematic of the set-up for a-C:H deposition by direct current discharge.
Figure 2.
Sliding ZrO2 ball moves across CoCrMo sample with 1 Hz.
Figure 2.
Sliding ZrO2 ball moves across CoCrMo sample with 1 Hz.
Figure 3.
Schematic of the test set up: (a) without hyaluronic gel (dry); (b) with hyaluronic gel Fn: normal load; s: sliding distance (stroke).
Figure 3.
Schematic of the test set up: (a) without hyaluronic gel (dry); (b) with hyaluronic gel Fn: normal load; s: sliding distance (stroke).
Figure 4.
Schematic of the wear trace in the disc with (a) the diameters d3 and d4, (b) Wq,disc.
Figure 4.
Schematic of the wear trace in the disc with (a) the diameters d3 and d4, (b) Wq,disc.
Figure 5.
Coefficient of friction COF during the dry sliding of ZrO2 ball against uncoated CoCrMo with 50 Hz or 1 Hz (Fn: 100 N).
Figure 5.
Coefficient of friction COF during the dry sliding of ZrO2 ball against uncoated CoCrMo with 50 Hz or 1 Hz (Fn: 100 N).
Figure 6.
Temperature change during the dry sliding of ZrO2 ball against uncoated CoCrMo with 50 Hz or 1 Hz (Fn: 100 N).
Figure 6.
Temperature change during the dry sliding of ZrO2 ball against uncoated CoCrMo with 50 Hz or 1 Hz (Fn: 100 N).
Figure 7.
Coefficient of friction COF during the sliding of ZrO2 ball against a-C:H coated CoCrMo without and with hyaluronic gel lubrication (Fn: 100 N, f: 50 Hz).
Figure 7.
Coefficient of friction COF during the sliding of ZrO2 ball against a-C:H coated CoCrMo without and with hyaluronic gel lubrication (Fn: 100 N, f: 50 Hz).
Figure 8.
Coefficient of friction COF during the sliding of ZrO2 ball against a-C:H coated CoCrMo without and with hyaluronic gel lubrication (Fn: 100 N, f: 1 Hz).
Figure 8.
Coefficient of friction COF during the sliding of ZrO2 ball against a-C:H coated CoCrMo without and with hyaluronic gel lubrication (Fn: 100 N, f: 1 Hz).
Figure 9.
Section with sharp spikes sections in COF curve without hyaluronic gel lubrication (a), smooth COF curve with hyaluronic gel lubrication (b) during sliding of ZrO2 ball against CoCrMo(a-C:H) (Fn: 100 N, f: 1 Hz).
Figure 9.
Section with sharp spikes sections in COF curve without hyaluronic gel lubrication (a), smooth COF curve with hyaluronic gel lubrication (b) during sliding of ZrO2 ball against CoCrMo(a-C:H) (Fn: 100 N, f: 1 Hz).
Figure 10.
ZrO2 ball wetted with hyaluronic gel before the wear test of a-C:H coated CoCrMo sample with 1 Hz.
Figure 10.
ZrO2 ball wetted with hyaluronic gel before the wear test of a-C:H coated CoCrMo sample with 1 Hz.
Figure 11.
Wear of uncoated and a-C:H coated discs at 1 Hz frequency (dry or with hyaluronic gel lubrication).
Figure 11.
Wear of uncoated and a-C:H coated discs at 1 Hz frequency (dry or with hyaluronic gel lubrication).
Figure 12.
Wear of uncoated and a-C:H coated discs at 50 Hz frequency (dry or with hyaluronic gel lubrication).
Figure 12.
Wear of uncoated and a-C:H coated discs at 50 Hz frequency (dry or with hyaluronic gel lubrication).
Figure 13.
Wear of a-C:H coated discs at different frequencies.
Figure 13.
Wear of a-C:H coated discs at different frequencies.
Figure 14.
Wear of ZrO2 balls sliding against a-C:H coated discs at different frequencies.
Figure 14.
Wear of ZrO2 balls sliding against a-C:H coated discs at different frequencies.
Figure 15.
Wear of ZrO2 balls at 1 Hz frequency (dry or with hyaluronic gel lubrication).
Figure 15.
Wear of ZrO2 balls at 1 Hz frequency (dry or with hyaluronic gel lubrication).
Figure 16.
Wear of ZrO2 balls at 50 Hz frequency (dry or with hyaluronic gel lubrication).
Figure 16.
Wear of ZrO2 balls at 50 Hz frequency (dry or with hyaluronic gel lubrication).
Figure 17.
Wear trace after sliding of ZrO2 ball against a-C:H coated CoCrMo without hyaluronic gel lubrication (dry, Fn: 100 N, f: 1 Hz); (a) overview of the wear trace; (b) edge of the wear trace.
Figure 17.
Wear trace after sliding of ZrO2 ball against a-C:H coated CoCrMo without hyaluronic gel lubrication (dry, Fn: 100 N, f: 1 Hz); (a) overview of the wear trace; (b) edge of the wear trace.
Figure 18.
Wear trace with wrinkled hydrogenated a-C:H and coating deadherence after dry sliding of ZrO2 ball against the CoCrMo(a-C:H) disc (Fn: 100 N, f: 1 Hz), SEM.
Figure 18.
Wear trace with wrinkled hydrogenated a-C:H and coating deadherence after dry sliding of ZrO2 ball against the CoCrMo(a-C:H) disc (Fn: 100 N, f: 1 Hz), SEM.
Figure 19.
Wear trace after sliding of ZrO2 ball against a-C:H coated CoCrMo with hyaluronic gel lubrication (Fn: 100 N, f: 1 Hz); (a) black and white image; (b) color image.
Figure 19.
Wear trace after sliding of ZrO2 ball against a-C:H coated CoCrMo with hyaluronic gel lubrication (Fn: 100 N, f: 1 Hz); (a) black and white image; (b) color image.
Figure 20.
Wear trace CoCrMo disc without a-C:H coating after dry sliding of ZrO2 ball, (Fn: 100 N, f: 1 Hz), SEM.
Figure 20.
Wear trace CoCrMo disc without a-C:H coating after dry sliding of ZrO2 ball, (Fn: 100 N, f: 1 Hz), SEM.
Figure 21.
Wear trace CoCrMo(a-C:H) disc after dry sliding of ZrO2 ball, (Fn: 100 N, f: 1 Hz), SEM.
Figure 21.
Wear trace CoCrMo(a-C:H) disc after dry sliding of ZrO2 ball, (Fn: 100 N, f: 1 Hz), SEM.
Figure 22.
Wear marks on the surface of ZrO2 ball after sliding against the uncoated CoCrMo disc, Fn: 100 N, f: 1 Hz, dry (3D image, digital microscopy).
Figure 22.
Wear marks on the surface of ZrO2 ball after sliding against the uncoated CoCrMo disc, Fn: 100 N, f: 1 Hz, dry (3D image, digital microscopy).
Figure 23.
Wear marks on the surface of ZrO2 ball after sliding against the uncoated CoCrMo disc, Fn: 100 N, f: 1 Hz, dry (2D image, digital microscopy).
Figure 23.
Wear marks on the surface of ZrO2 ball after sliding against the uncoated CoCrMo disc, Fn: 100 N, f: 1 Hz, dry (2D image, digital microscopy).
Figure 24.
Wear marks on the surface of ZrO2 ball after sliding against the a-C:H-coated CoCrMo disc, Fn: 100 N, f: 1 Hz, dry (3D image, digital microscopy).
Figure 24.
Wear marks on the surface of ZrO2 ball after sliding against the a-C:H-coated CoCrMo disc, Fn: 100 N, f: 1 Hz, dry (3D image, digital microscopy).
Figure 25.
Wear marks on the surface of ZrO2 ball after sliding against the a-C:H-coated CoCrMo disc, Fn: 100 N, f: 1 Hz, dry (2D image, digital microscopy).
Figure 25.
Wear marks on the surface of ZrO2 ball after sliding against the a-C:H-coated CoCrMo disc, Fn: 100 N, f: 1 Hz, dry (2D image, digital microscopy).
Figure 26.
Wear marks on the surface of ZrO2 ball after sliding against the a-C:H-coated CoCrMo disc, Fn: 100 N, f: 1 Hz, hyaluronic gel (3D image, digital microscopy).
Figure 26.
Wear marks on the surface of ZrO2 ball after sliding against the a-C:H-coated CoCrMo disc, Fn: 100 N, f: 1 Hz, hyaluronic gel (3D image, digital microscopy).
Figure 27.
Wear marks on the surface of ZrO2 ball after sliding against the a-C:H-coated CoCrMo disc, Fn: 100 N, f: 1 Hz, hyaluronic gel (2D image, digital microscopy).
Figure 27.
Wear marks on the surface of ZrO2 ball after sliding against the a-C:H-coated CoCrMo disc, Fn: 100 N, f: 1 Hz, hyaluronic gel (2D image, digital microscopy).
Figure 28.
Raman spectra of a-C:H coatings on CoCrMo (as deposited and before wear tests).
Figure 28.
Raman spectra of a-C:H coatings on CoCrMo (as deposited and before wear tests).
Figure 29.
Raman spectra of hydrogenated a-C:H coatings on CoCrMo after wear tests w/o hyaluron-gel (Fn: 100 N, f: 1 Hz) (a) groove within the a-C:H wear trace, (b) crack within the a-C:H wear trace, (c) coherent failure within the a-C:H wear trace, (d) CoCrMo substrate after delamination of the coating.
Figure 29.
Raman spectra of hydrogenated a-C:H coatings on CoCrMo after wear tests w/o hyaluron-gel (Fn: 100 N, f: 1 Hz) (a) groove within the a-C:H wear trace, (b) crack within the a-C:H wear trace, (c) coherent failure within the a-C:H wear trace, (d) CoCrMo substrate after delamination of the coating.
Figure 30.
Measurement positions for Raman spectroscopy in the wear trace of a-C:H coated CoCrMo after dry sliding of ZrO
2 ball (F
n: 100 N, f: 1 Hz). For explanation of (
a–
d) see
Figure 29.
Figure 30.
Measurement positions for Raman spectroscopy in the wear trace of a-C:H coated CoCrMo after dry sliding of ZrO
2 ball (F
n: 100 N, f: 1 Hz). For explanation of (
a–
d) see
Figure 29.
Figure 31.
Shearing of a-C:H at the coatings surface with rearrangement of hydrogen during sliding is essential for transfer film formation.
Figure 31.
Shearing of a-C:H at the coatings surface with rearrangement of hydrogen during sliding is essential for transfer film formation.
Figure 32.
Plastic deformation of the substrate due to cyclic application of high loads and cyclic interfacial cracking with delamination.
Figure 32.
Plastic deformation of the substrate due to cyclic application of high loads and cyclic interfacial cracking with delamination.
Table 1.
Processing parameters for diamond-like carbon coatings deposition
Table 1.
Processing parameters for diamond-like carbon coatings deposition
Electric Parameters | |
---|
Hot cathode heating current UH | 30–80 A |
Discharge current | 0.1–1 A |
Current through substrate holder | 10–400 mA |
Voltage between cathode and anode grid | 30–300 V |
Bias voltage | 0–3.5 kV |
Table 2.
Parameters of the wear tests
Table 2.
Parameters of the wear tests
Disc | Ball | Intermediate Medium | Normal Force Fn (N) | Frequency (Hz) | Time (s) |
---|
CoCrMo | ZrO2 | dry | 100 | 1 | 1800 |
CoCrMo(a-C:H) | ZrO2 | dry | 100 | 1 | 1800 |
CoCrMo | ZrO2 | hyaluronic gel | 100 | 1 | 1800 |
CoCrMo(a-C:H) | ZrO2 | hyaluronic gel | 100 | 1 | 1800 |
CoCrMo | ZrO2 | dry | 100 | 50 | 1800 |
CoCrMo(a-C:H) | ZrO2 | dry | 100 | 50 | 1800 |
CoCrMo | ZrO2 | hyaluronic gel | 100 | 50 | 1800 |
CoCrMo(a-C:H) | ZrO2 | hyaluronic gel | 100 | 50 | 1800 |
Table 3.
Coefficients of friction
Table 3.
Coefficients of friction
Disc | Ball | Intermediate Medium | f (Hz) | COFmax | COF15 | COF30 |
---|
CoCrMo | ZrO2 | dry | 1 | 0.482 | 0.438 | 0.394 |
CoCrMo(a-C:H) | ZrO2 | dry | 1 | 0.369 | 0.113 | 0.105 |
CoCrMo | ZrO2 | hyaluronic gel | 1 | 0.401 | 0.308 | 0.204 |
CoCrMo(a-C:H) | ZrO2 | hyaluronic gel | 1 | 0.137 | 0.096 | 0.105 |
CoCrMo | ZrO2 | dry | 50 | 0.751 | 0.637 | 0.724 |
CoCrMo(a-C:H) | ZrO2 | dry | 50 | 0.678 | 0.466 | 0.552 |
CoCrMo | ZrO2 | hyaluronic gel | 50 | 0.733 | 0.310 | 0.277 |
CoCrMo(a-C:H) | ZrO2 | hyaluronic gel | 50 | 0.549 | 0.433 | 0.445 |
Table 4.
Wear rates according the standard DIN 51834-3
Table 4.
Wear rates according the standard DIN 51834-3
Disc | Ball | Intermediate Medium | f (Hz) | Wq,disc (µm2) | Wear Rate Disc (mm3/Nm) | Wear Rate Ball (mm3/Nm) |
---|
CoCrMo | ZrO2 | dry | 1 | 9422.93 | 67.01 × 10−6 | 39.13 × 10−6 |
CoCrMo(a-C:H) | ZrO2 | dry | 1 | 1231.11 | 21.09 × 10−6 | 18.37 × 10−6 |
CoCrMo | ZrO2 | hyaluronic gel | 1 | 2921.09 | 26.07 × 10−6 | 0.893 × 10−6 |
CoCrMo(a-C:H) | ZrO2 | hyaluronic gel | 1 | 27.09 | 0.16 × 10−6 | - |
CoCrMo | ZrO2 | dry | 50 | 260,716.36 | 77.37 × 10−6 | 13.19 × 10−6 |
CoCrMo(a-C:H) | ZrO2 | dry | 50 | 183,843.32 | 27.23 × 10−6 | 0.015 × 10−6 |
CoCrMo | ZrO2 | hyaluronic gel | 50 | 23,361.03 | 2.979 × 10−6 | 0.000762 × 10−6 |
CoCrMo(a-C:H) | ZrO2 | hyaluronic gel | 50 | 4313.19 | 0.57 × 10−6 | 1.87 × 10−6 |
Table 5.
Results from Raman spectroscopy (λ = 532 nm) of a-C:H coated medical grade CoCrMo
Table 5.
Results from Raman spectroscopy (λ = 532 nm) of a-C:H coated medical grade CoCrMo
a-C:H, as Deposited | D Peak Position/cm−1 | G Peak Position/cm−1 | ID/IG Ratio |
---|
a-C:H, as deposited position (1) | 1362.30 | 1541.29 | 0.48 |
a-C:H, as deposited position (2) | 1384.07 | 1542.12 | 0.33 |
a-C:H, as deposited position (3) | 1396.56 | 1542.56 | 0.20 |
Table 6.
Results from Raman spectroscopy (λ = 532 nm) of a-C:H coated medical grade CoCrMo after wear tests (Fn: 100 N; f: 1 Hz; dry)
Table 6.
Results from Raman spectroscopy (λ = 532 nm) of a-C:H coated medical grade CoCrMo after wear tests (Fn: 100 N; f: 1 Hz; dry)
CoCrMo(a-C:H) after ZrO2 Sliding (100 N; 1 Hz; Dry) | D Peak Position/cm−1 | G Peak Position/cm−1 | ID/IG Ratio |
---|
- (a)
groove within the wear trace in a-C:H
| 1408.81 | 1549.54 | 0.39 |
- (b)
crack within the wear trace in a-C:H
| 1412.01 | 1547.33 | 0.39 |
- (c)
deepening within the a-C:H wear trace (coherent failure)
| 1396.01 | 1545.22 | 0.22 |
- (d)
deepening within the wear trace (after coating delamination)
| - | - | - |