Table 1.
The flow rate of the working gases during the deposition of TiCN coatings on the steel substrate
| Material | Flow rate (×10−3 m3/h) | |||
|---|---|---|---|---|
| Ar | N2 | C2H2 | ||
| Coating | TiC | 1.1 | - | 0.47 |
| TiN | 1.1 | 0.45 | - | |
| TiCN | 1.35 | 0.225 | 0.225 | |
Table 2.
Surface roughness parameters (ISO 25178) of TiCN coatings and the steel substrate before and after friction tests
| Material | Average values of surface roughness parameters before friction tests | |||||||
|---|---|---|---|---|---|---|---|---|
| Sa | Sq | Sz | Ssk | Sku | Sp | Sv | ||
| Coating | TiC | 0.508 | 0.592 | 2.548 | 0.164 | 2.018 | 1.375 | 1.173 |
| TiN | 0.278 | 0.327 | 1.946 | 0.027 | 2.151 | 0.763 | 1.183 | |
| TiCN | 0.251 | 0.309 | 2.317 | −0.797 | 6.745 | 0.666 | 1.651 | |
| Substrate | AISI 304 steel | 0.567 | 0.680 | 3.585 | 0.129 | 2.261 | 1.917 | 1.667 |
| Average values of surface roughness parameters after friction tests | ||||||||
|---|---|---|---|---|---|---|---|---|
| Coating | TiC | 0.613 | 0.731 | 4.172 | 0.012 | 2.503 | 1.941 | 2.2320 |
| TiN | 0.597 | 0.744 | 5.788 | −0.709 | 3.828 | 2.013 | 3.775 | |
| TiCN | 0.275 | 0.336 | 1.866 | 0.212 | 2.532 | 1.017 | 0.849 | |
| Substrate | AISI 304 steel | 0.909 | 1.196 | 11.867 | 0.986 | 10.617 | 4.065 | 7.803 |
Fig. 1.
Friction pair on tribotester ball-on-plate (1 – sample with tested coating, 2 – silicon carbide ball, 3 – ball holder, Fn – normal load, v – sliding speed in reciprocating motion)
Fig. 2.
Examples of changes in the friction coefficient as a function of successive movements (cycles) for the tested coatings: (A) TiC, (B) TiN, (C) TiCN. TiCN, titanium carbonitride
Table 3.
The average coefficient of friction for the tested coatings and the confidence intervals for the initial (Cycle 1–20) and final friction period (Cycle 90–100)
| Material | Coefficient of friction | Confidence interval | Coefficient of friction | Confidence interval | |
|---|---|---|---|---|---|
| Cycle: 1–20 | Cycle: 90–100 | ||||
| Coatings | TiC | 0.122 | ±0.003 | 0.143 | ±0.002 |
| TiN | 0.165 | ±0.001 | 0.168 | ±0.001 | |
| TiCN | 0.145 | ±0.002 | 0.166 | ±0.002 | |
| Substrate | AISI 304 steel | 0.139 | ±0.002 | 0.152 | ±0.002 |
Fig. 3.
Average coefficient of friction for TiCN coatings and steel substrate for the initial (Cycle 1–20) and final friction period (Cycle 90–100) (error bars correspond to confidence intervals of the confidence level α = 0.05). TiCN, titanium carbonitride
Fig. 4.
Example of wear (groove) test results on a TiC coating surface using a 3D surface metrology microscope: (A, B) wear track, (C) cross-section of wear track
Fig. 5.
Example of wear (groove) test results on a TiN coating surface using a 3D surface metrology microscope: (A, B) wear track, (C) cross-section of wear track
Fig. 6.
Example of wear (groove) test results on a TiCN coating surface using a 3D surface metrology microscope: (A, B) wear track, (C) cross-section of wear track. TiCN, titanium carbonitride
Table 4.
Wear of TiCN coatings as an average of the maximum friction track depth after 100 cycles of movement
| Material | Wear (μm) | Confidence interval |
|---|---|---|
| TiC | 4.64 | ±0.58 |
| TiN | 3.05 | ±0.17 |
| TiCN | 5.65 | ±0.38 |
Fig. 7.
Wear of TiCN coatings as an average of the maximum friction track depth after 100 cycles of movement during tribological tests (error bars correspond to confidence intervals of the confidence level α = 0.05). TiCN, titanium carbonitride
Fig. 8.
SEM microphotographs of friction tracks for coatings: (A) TiC, (B)TiN, (C) TiCN. The arrows indicate the area of cracking and the detachment of the coating from the substrate. SEM, scanning electron microscope; TiCN, titanium carbonitride
Fig. 9.
Normal force Fn and frictional force Ft versus distance L in the scratch test for coatings: (A) TiC, (B) TiN,(C) TiCN. TiCN, titanium carbonitride
Fig. 10.
Scratch microphotographs for TiC; (A) normal force in the range Fn = 10–1,400 mN, (B) normal force in the range Fn = 1,450–2,400 mN, (C) normal force in the range Fn = 1,250–1,500 mN, (D) normal force in the range Fn = 1,250–1,500 mN, (E) normal force in the range Fn = 2,000–2,400 mN, (F) normal force Fn = 2,000–2,400 mN. The arrows indicate the area of the detachment of the coating from the substrate
Fig. 11.
Scratch microphotographs for TiN; (A) normal force in the Fn range = 10–1,200 mN, (B) normal force in the Fn range Fn = 1,250–1,500 mN, (C) normal force in the Fn range Fn = 1,550–1,850 mN, (D) normal force Fn = 1,800 mN. The arrows indicate the area of cracking and the detachment of the coating from the substrate
Fig. 12.
Scratch microphotographs for TiCN; (A) normal force in the Fn range Fn = 10–860 mN, (B) normal force in the Fn range Fn = 1,050–2,500 mN, (C) normal force in the Fn range Fn = 800–1,200 mN, (D) normal force Fn = 1,350–2,400 mN. The arrows indicate the area of the detachment of the coating from the substrate. TiCN, titanium carbonitride